Metabolic myopathy

Last updated
Metabolic myopathy
Hydrolysis of ATP.png
Hydrolysis of ATP
1008 Skeletal Muscle Contraction.jpg
Skeletal muscle contraction

Metabolic myopathies are myopathies that result from defects in biochemical metabolism that primarily affect muscle. They are generally genetic defects (inborn errors of metabolism) that interfere with the ability to create energy, causing a low ATP reservoir within the muscle cell. [1] [2]

Contents

Types

Metabolic myopathies are generally caused by an inherited genetic mutation, an inborn error of metabolism. (In livestock, an acquired environmental GSD is caused by intoxication with the alkaloid castanospermine.) [3] Metabolic myopathies cause the underproduction of adenosine triphosphate (ATP) within the muscle cell. [4]

The genetic mutation typically has an autosomal recessive hereditary pattern making it fairly rare to inherit, and even more rarely it can be caused by a random de novo genetic mutation, or autosomal dominant, X-linked, or mitochondrial. [1] Metabolic myopathies are categorized by the metabolic pathway to which the deficient enzyme or transport protein belongs. The main categories of metabolic myopathies are listed below: [5]

Symptoms and signs

In the event more ATP is needed from the affected pathway, the lack of it becomes an issue and symptoms develop. People with a metabolic myopathy often experience symptoms such as:

The degree of symptoms varies greatly from person to person and is dependent on the severity of enzymatic or transport protein defect. In extreme cases it can lead to rhabdomyolysis. [19] The symptoms experienced also depend on which metabolic pathway is impaired, as different metabolic pathways produce ATP at different time periods during activity and rest, as well as the type of activity (anaerobic or aerobic) and its intensity (level of ATP consumption). [ citation needed ]

A majority of patients with metabolic myopathies have dynamic rather than static findings, typically experiencing exercise intolerance, muscle pain, and cramps with exercise rather than fixed muscle weakness. [1] [20] However, a minority of metabolic myopathies have fixed muscular weakness rather than exercise intolerance, imitating an inflammatory myopathy or limb girdle muscular dystrophy. It is uncommon that both static and dynamic signs predominate. [1] [20]

Mechanism

At the cellular level, metabolic myopathies lack some kind of enzyme or transport protein that prevents the chemical reactions necessary to create adenosine triphosphate (ATP). [1] [17] ATP is often referred to as the "molecular unit of currency" of intracellular energy transfer. The lack of ATP prevents the muscle cells from being able to function properly. Some people with a metabolic myopathy never develop symptoms due to the body's ability to produce enough ATP through alternative pathways (e.g. the majority of those with AMP-deaminase deficiency are asymptomatic [1] [21] ).

H2O + ATP → H+ + ADP + Pi + energy → muscle contraction [22]

ATP is needed for muscle contraction by two processes:

  1. Firstly, ATP is needed for transport proteins to actively transport calcium ions into the sarcoplasmic reticulum (SR) of the muscle cell between muscle contractions. Afterwards, when a nerve signal is received, calcium channels in the SR open briefly and calcium rushes into the cytosol by selective diffusion (which does not use ATP) in what is called a "calcium spark." The diffusion of calcium ions into the cytosol causes the myosin strands of the myofibril to become exposed, and the myosin strands pull the actin microfilaments together. The muscle begins to contract. [23]
  2. Secondly, ATP is needed to allow the myosin to release and pull again, so that the muscle can contract further in what is known as the sliding filament model. [23]

ATP is consumed at a high rate by contracting muscles. The need for ATP in muscle cells is illustrated by the phenomenon of Rigor mortis, which is the muscle rigidity that occurs in dead bodies for a short time after death. In these muscles, all the ATP has been used up and in the absence of further ATP being generated, the calcium transport proteins stop pumping calcium ions into the sarcoplasmic reticulum and the calcium ions gradually leak out. This causes the myosin proteins to grab the actin and pull once, but without further supply of ATP, cannot release and pull again. The muscles therefore remain rigid in the position at death until the binding of myosin to actin begins to break down and they become loose again. [23]

Diagnosis

The symptoms of a metabolic myopathy can be easily confused with the symptoms of another disease. As genetic sequencing research progresses, a non-invasive neuromuscular panel DNA test can help make a diagnosis. Whole genome sequencing is required in more complex cases. [1] If the DNA test is inconclusive (negative or VUS), then a muscle biopsy is necessary for an accurate diagnosis. In mitochondrial myopathies involving a single mtDNA deletion, DNA would have to be tested from affected muscle tissue rather than saliva or blood as unaffected tissues would show normal or near normal levels of mtDNA. [1] [24] [25]

A blood test for creatine kinase (CK) can be done under normal circumstances to test for signs of tissue breakdown, or with an added cardio portion that can indicate if muscle breakdown is occurring. In metabolic myopathies, baseline CK is either normal or elevated. [8] An electromyography (EMG) test is sometimes taken in order to rule out other disorders if the cause of fatigue is unknown. [4] In metabolic myopathies, the EMG is either normal or myopathic, but spontaneous activity is usually absent. [8]

An exercise stress test can be used to determine an inappropriate rapid heart rate (sinus tachycardia) response to exercise, which is seen in GSD-V, other glycogenoses, and mitochondrial myopathies. [7] [9] A 12 Minutes Walk Test (12MWT) can also be used to determine "second wind" which is also seen in McArdle disease (GSD-V) and phosphoglucomutase deficiency (PGM1-CDG/CDG1T/GSD-XIV). [7] [26]

A cardiopulmonary exercise test can measure both heart rate and breathing, to evaluate the oxygen cost (∆V'O2/∆Work-Rate) during incremental exercise. In both glycogenoses and mitochondrial myopathies, patients displayed an increased oxygen cost during exercise compared to control subjects; and therefore, can perform less work for a given V̇O2 consumption during submaximal daily life exercises. [9] [10]

In fatty acid oxidation disorders (FAOD), while at rest, some exhibit cardiac arrhythmia (commonly various forms of tachycardia, but more rarely, conduction disorders or acute bradycardia); while others have a normal heart rhythm. [27]

Some GSDs and a mitochondrial myopathy are known to have a pseudoathletic appearance. McArdle disease (GSD-V) and late-onset Pompe disease (GSD-II) are known to have hypertrophy, particularly of the calf muscles. [14] [15] Cori/Forbes disease (GSD-III) is known to have hypertrophy of the sternocleidomastoid, trapezius, quadriceps, and thigh muscles. [13] [28] [29] [30] Muscular dystrophy, limb-girdle, type 1H (which as of 2017 was excluded from LGMD for showing signs on muscle biopsy as being a mitochondrial myopathy, but not yet assigned new nomenclature) [31] is also known to have hypertrophy of the calf muscles. [32] Hereditary myopathy with lactic acidosis (HML), another mitochondrial myopathy, also has hypertrophy of the calf muscles in some. [16] [33]

Blood test may show a disturbance in pH, with lactic acidosis (low pH) in mitochondrial myopathies either at rest or exercise-induced. [34] Glycogen storage diseases may show transient exercise-induced alkalosis (high pH), hyperammonemia, and myogenic hyperuricemia. [35] [36] [37] [38] [39] During a non-ischemic forearm exercise test, in GSDs the plasma lactate typically fails to rise (and may fall below resting levels); except for a few GSDs such as phosphoglucomutase deficiency (GSD-XIV), [39] deficiency of functioning myophosphorylase-a (autosomal dominant PYGM), [40] phosphorylase-b kinase deficiency (GSD-IXd), and Pompe disease (GSD-II) where lactate production is normal. [2] In myoadenylate deaminase deficiency (AMPD1 deficiency), there is no rise in ammonia. [2] Some fatty acid oxidation disorders show lactic acidosis, hypoketotic hypoglycaemia and hyperammonemia, while others are asymptomatic. [2] [41] [42]

Differentiating between different types of metabolic myopathies can be difficult due to the similar symptoms of each type such as myoglobinuria and exercise intolerance. It has to be determined whether the patient has fixed (static) or exercise-induced (dynamic) manifestations; and if exercise-related, what kind of exercise, before extensive exercise-related lab testing is done to determine the underlying cause. [5]

Adequate knowledge is required of the body's bioenergetic systems, [8] [43] including:

For example, leisurely-paced walking and fast-paced walking on level ground (no incline) are both aerobic, but fast-paced walking relies on more muscle glycogen because of the higher intensity (which would cause exercise intolerance symptoms in those with muscle glycogenoses that hadn't yet achieved "second wind"). [11] [7] [18] [44]

When walking at a leisurely pace on level ground (no incline), but there is loose gravel or sand, long grass, snow, mud, or walking into a headwind, that added resistance (requiring more effort) makes the activity more reliant on muscle glycogen also. [7] [18] These and other surfaces, such as ice, can make you tense your muscles (which is anearobic requiring muscle glycogen) as you protect yourself from slipping or falling. [7] [18]

Those with muscle glycogenoses can maintain a healthy life of exercise by learning activity adaptations, utilizing the bioenergetic systems that are available to them. Depending on the type of activity and whether they are in second wind, they slow their pace or rest briefly when need be, to make sure not to empty their "ATP reservoir." [7] [18]

Main distinguishing features in metabolic myopathies with exercise intolerance [8] [9] [7] [11] [45] [27] [14] [15] [28] [29] [31] [32] [46] [36] [35] [37] [41]
Exercise intolerance

signs and symptoms

Triggered after prolonged activity,

and low-intensity aerobic activity

  • Muscle fatigue and pain (myalgia) with exercise;
  • Normal, rapid heart rate (tachycardia), or other arrhythmia at rest;
  • Also triggered by the 3 Fs: fasting, fever, or freezing (prolonged exposure to cold temperatures);
  • Cramps possible, but not as prominent as in muscle GSDs;
  • Rhabdomyolysis and myoglobinuria possible;
  • Baseline creatine kinase normal;
  • Plasma pH normal or lactic acidosis;
  • With or without hypoketotic hypoglycaemia and hyperammonemia.
Fatty acid oxidation disorder
  • Breathlessness (dyspnea) and premature muscle fatigue with exercise;
  • Inappropriate rapid heart rate response to exercise;
  • Muscle fatigue commonly described as heavy legs or burning;
  • May have a pseudoathletic appearance (particularly of the calf muscles);
  • Cramps possible, but not as prominent as in muscle GSDs;
  • Rhabdomyolysis and myoglobinuria possible;
  • Baseline lactic acid and creatine kinase normal or elevated;
  • Plasma pH disturbance of lactic acidosis (at rest and/or with exercise).
Mitochondrial myopathy
Triggered early in exercise

(within seconds to minutes), by high-intensity aerobic activity

and all anaerobic activity

  • "Second wind" or "out of wind" with exercise;
  • Rapid (tachypnea) and commonly heavy breathing (hyperpnea) with exercise (exercise hyperventilation);
  • Inappropriate rapid heart rate response to exercise;
  • Muscle fatigue, pain (myalgia), and cramps with exercise;
  • Sucrose taken shortly before exercise mitigates symptoms in glycogenolytic defects (e.g. GSD-V) or worsens symptoms in glycolytic defects (e.g. GSD-VII);
  • Ketosis improves symptoms;
  • May have a pseudoathletic appearance (particularly of the calf muscles);
  • Rhabdomyolysis and myoglobinuria possible;
  • Baseline creatine kinase normal or elevated;
  • Plasma pH disturbance of alkalosis during exercise;
  • Exercise-induced hyperammonemia and myogenic hyperuricemia with lactate failing to rise (rarely normal).
Glycogen storage disease

Treatment

Metabolic myopathies have varying levels of symptoms, being most severe when developed during infancy. Those who do not develop a form of a metabolic myopathy until they are in their young adult or adult life tend to have more treatable symptoms that can be helped with a change in diet and exercise. [19] It might be more accurate to say that metabolic myopathies described as adult-onset, it isn't necessarily that they didn't develop in infancy (they are inborn—from birth—errors of metabolism) but that they didn't display severe enough symptoms to warrant the attention of medical professionals until their adult years (severe symptoms such as rhabdomyolysis, fixed muscle weakness due to years of repetitive injury, or the de-conditioning of muscles from a more sedentary adult lifestyle which exacerbated symptoms).[ citation needed ]

Due to the rare nature of these diseases, it is very common to be misdiagnosed, even misdiagnosed multiple times. [11] [47] [43] [48] Once a correct diagnosis has been made, in adult years, looking back symptoms were present since childhood, but either brushed-off as growing pains, laziness, or told that they just needed to exercise more. [43] [47] [11] It is especially difficult to get a diagnosis when symptoms are dynamic (exercise-induced), such as in muscle glycogenoses. [11] [20] [43] Sitting in a doctor's office (at rest) or doing movements that only last a few seconds (within the time limit of the phosphagen system) the patient wouldn't display any noticeable abnormalities (such as muscle fatigue, cramping, or breathlessness).[ citation needed ]

A brief or only mildly elevated heart rate (heart rate taken while sitting down after recently walking across the room or getting up on the examination table) might be assumed to be due to anxiety or illness rather than exercise-induced inappropriate rapid heart rate due to an ATP shortage in the muscle cells. In the absence of severe symptoms (such as hepatomegaly, cardiomyopathy, hypoglycemia, lactic acidosis, myoglobinuria, rhabdomyolysis, acute compartment syndrome or renal failure), it is understandable that a disease would not be noticed by medical professionals for years, when at rest the patient appears completely normal.[ citation needed ]

Depending on what enzyme is affected, a high-protein or low-fat diet may be recommended along with mild exercise. It is important for people with metabolic myopathies to consult with their doctors for a treatment plan in order to prevent acute muscle breakdowns while exercising that lead to the release of muscle proteins into the bloodstream that can cause kidney damage. [4]

A ketogenic diet has a remarkable effect on CNS-symptoms in PDH-deficiency and has also been tried in complex I deficiency. [49] A ketogenic diet has demonstrated beneficial for McArdle disease (GSD-V) as ketones readily convert to acetyl CoA for oxidative phosphorylation, whereas free fatty acids take a few minutes to convert into acetyl CoA. [46] As of 2022, another study on a ketogenic diet and McArdle disease (GSD-V) is underway. [50]

For McArdle disease (GSD-V), regular aerobic exercise utilizing "second wind" to enable the muscles to become aerobically conditioned, as well as anaerobic exercise that follows the activity adaptations so as not to cause muscle injury, helps to improve exercise intolerance symptoms and maintain overall health. [7] [11] [51] [52] Studies have shown that regular low-moderate aerobic exercise increases peak power output, increases peak oxygen uptake (VO2 peak), lowers heart rate, and lowers serum CK in individuals with McArdle disease. [51] [52]

Regardless of whether the patient experiences symptoms of muscle pain, muscle fatigue, or cramping, the phenomenon of second wind having been achieved is demonstrable by the sign of an increased heart rate dropping while maintaining the same speed on the treadmill. [52] [43] Inactive patients experienced second wind, demonstrated through relief of typical symptoms and the sign of an increased heart rate dropping, while performing low-moderate aerobic exercise (walking or brisk walking). [52] [43] Conversely, patients that were regularly active did not experience the typical symptoms during low-moderate aerobic exercise (walking or brisk walking), but still demonstrated second wind by the sign of an increased heart rate dropping. [52] [43] For the regularly active patients, it took more strenuous exercise (very brisk walking/jogging or bicycling) for them to experience both the typical symptoms and relief thereof, along with the sign of an increased heart rate dropping, demonstrating second wind. [52] [43]

Society and culture

See also

Related Research Articles

Kocher–Debré–Semelaigne syndrome (KDSS) is hypothyroidism in infancy or childhood characterised by lower extremity or generalized muscular hypertrophy, myxoedema, short stature, and cognitive impairment.

<span class="mw-page-title-main">Adenosine monophosphate deaminase deficiency type 1</span> Metabolic disorder leading to muscle dysfunction

Adenosine monophosphate deaminase deficiency type 1 or AMPD1, is a human metabolic disorder in which the body consistently lacks the enzyme AMP deaminase, in sufficient quantities. This may result in exercise intolerance, muscle pain and muscle cramping. The disease was formerly known as myoadenylate deaminase deficiency (MADD).

<span class="mw-page-title-main">Glycogen storage disease type V</span> Human disease caused by deficiency of a muscle enzyme

Glycogen storage disease type V, also known as McArdle's disease, is a metabolic disorder, one of the metabolic myopathies, more specifically a muscle glycogen storage disease, caused by a deficiency of myophosphorylase. Its incidence is reported as one in 100,000, roughly the same as glycogen storage disease type I.

<span class="mw-page-title-main">Glycogen storage disease</span> Medical condition

A glycogen storage disease is a metabolic disorder caused by a deficiency of an enzyme or transport protein affecting glycogen synthesis, glycogen breakdown, or glucose breakdown, typically in muscles and/or liver cells.

Alkalosis is the result of a process reducing hydrogen ion concentration of arterial blood plasma (alkalemia). In contrast to acidemia, alkalemia occurs when the serum pH is higher than normal. Alkalosis is usually divided into the categories of respiratory alkalosis and metabolic alkalosis or a combined respiratory/metabolic alkalosis.

<span class="mw-page-title-main">Phosphoglucomutase</span> Metabolic enzyme

Phosphoglucomutase is an enzyme that transfers a phosphate group on an α-D-glucose monomer from the 1 to the 6 position in the forward direction or the 6 to the 1 position in the reverse direction.

<span class="mw-page-title-main">Phosphofructokinase deficiency</span> Medical condition

Phosphofructokinase deficiency is a rare muscular metabolic disorder, with an autosomal recessive inheritance pattern. It is characterized as a deficiency in the Phosphofructokinase (PFK) enzyme throughout the body, including the skeletal muscles and red blood cells. Phosphofrucotkinase is an enzyme involved in the glycolytic process. The lack of PFK blocks the completion of the glycolytic pathway. Therefore, all products past the block would be deficient, including Adenosine triphosphate (ATP).

<span class="mw-page-title-main">Exercise intolerance</span> Inability to perform physical exercise at normal levels

Exercise intolerance is a condition of inability or decreased ability to perform physical exercise at the normally expected level or duration for people of that age, size, sex, and muscle mass. It also includes experiences of unusually severe post-exercise pain, fatigue, nausea, vomiting or other negative effects. Exercise intolerance is not a disease or syndrome in and of itself, but can result from various disorders.

<span class="mw-page-title-main">Hitting the wall</span> Sudden fatigue during endurance sports

In endurance sports such as road cycling and long-distance running, hitting the wall or the bonk is a condition of sudden fatigue and loss of energy which is caused by the depletion of glycogen stores in the liver and muscles. Milder instances can be remedied by brief rest and the ingestion of food or drinks containing carbohydrates. Otherwise, it can be remedied by attaining second wind by either resting for approximately 10 minutes or by slowing down considerably and increasing speed slowly over a period of 10 minutes. Ten minutes is approximately the time that it takes for free fatty acids to sufficiently produce ATP in response to increased demand.

In biochemistry and metabolism, beta oxidation (also β-oxidation) is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA. Acetyl-CoA enters the citric acid cycle, generating NADH and FADH2, which are electron carriers used in the electron transport chain. It is named as such because the beta carbon of the fatty acid chain undergoes oxidation and is converted to a carbonyl group to start the cycle all over again. Beta-oxidation is primarily facilitated by the mitochondrial trifunctional protein, an enzyme complex associated with the inner mitochondrial membrane, although very long chain fatty acids are oxidized in peroxisomes.

<span class="mw-page-title-main">Sinus tachycardia</span> Sinus rhythm with a rate that is higher than normal

Sinus tachycardia is a sinus rhythm of the heart, with an increased rate of electrical discharge from the sinoatrial node, resulting in a tachycardia, a heart rate that is higher than the upper limit of normal.

<span class="mw-page-title-main">Mitochondrial myopathy</span> Muscle disorders caused by mitochondrial dysfunction

Mitochondrial myopathies are types of myopathies associated with mitochondrial disease. Adenosine triphosphate (ATP), the chemical used to provide energy for the cell, cannot be produced sufficiently by oxidative phosphorylation when the mitochondrion is either damaged or missing necessary enzymes or transport proteins. With ATP production deficient in mitochondria, there is an over-reliance on anaerobic glycolysis which leads to lactic acidosis either at rest or exercise-induced.

<span class="mw-page-title-main">Myophosphorylase</span> Muscle enzyme involved in glycogen breakdown

Myophosphorylase or glycogen phosphorylase, muscle associated (PYGM) is the muscle isoform of the enzyme glycogen phosphorylase and is encoded by the PYGM gene. This enzyme helps break down glycogen into glucose-1-phosphate, so it can be used within the muscle cell. Mutations in this gene are associated with McArdle disease, a glycogen storage disease of muscle.

<span class="mw-page-title-main">Bioenergetic systems</span> Metabolic processes for energy production

Bioenergetic systems are metabolic processes that relate to the flow of energy in living organisms. Those processes convert energy into adenosine triphosphate (ATP), which is the form suitable for muscular activity. There are two main forms of synthesis of ATP: aerobic, which uses oxygen from the bloodstream, and anaerobic, which does not. Bioenergetics is the field of biology that studies bioenergetic systems.

Second wind is a phenomenon in endurance sports, such as marathons or road running, whereby an athlete who is out of breath and too tired to continue, finds the strength to press on at top performance with less exertion. The feeling may be similar to that of a "runner's high", the most obvious difference being that the runner's high occurs after the race is over. In muscle glycogenoses, an inborn error of carbohydrate metabolism impairs either the formation or utilization of muscle glycogen. As such, those with muscle glycogenoses do not need to do prolonged exercise to experience "hitting the wall". Instead, signs of exercise intolerance, such as an inappropriate rapid heart rate response to exercise, are experienced from the beginning of an activity, and some muscle GSDs can achieve second wind within about 10 minutes from the beginning of the aerobic activity, such as walking. (See below in pathology).

<span class="mw-page-title-main">Inborn errors of carbohydrate metabolism</span> Medical condition

Inborn errors of carbohydrate metabolism are inborn error of metabolism that affect the catabolism and anabolism of carbohydrates.

<span class="mw-page-title-main">Fatty-acid metabolism disorder</span> Medical condition

A broad classification for genetic disorders that result from an inability of the body to produce or utilize an enzyme or transport protein that is required to oxidize fatty acids. They are an inborn error of lipid metabolism, and when it affects the muscles also a metabolic myopathy.

Hoffmann syndrome is a rare form of hypothyroid myopathy and is not to be confused with Werdnig-Hoffmann disease.

<span class="mw-page-title-main">Purine nucleotide cycle</span> Protein metabolic pathway

The Purine Nucleotide Cycle is a metabolic pathway in protein metabolism requiring the amino acids aspartate and glutamate. The cycle is used to regulate the levels of adenine nucleotides, in which ammonia and fumarate are generated. AMP converts into IMP and the byproduct ammonia. IMP converts to S-AMP (adenylosuccinate), which then converts to AMP and the byproduct fumarate. The fumarate goes on to produce ATP (energy) via oxidative phosphorylation as it enters the Krebs cycle and then the electron transport chain. Lowenstein first described this pathway and outlined its importance in processes including amino acid catabolism and regulation of flux through glycolysis and the Krebs cycle.

References

  1. 1 2 3 4 5 6 7 8 Urtizberea, Jon Andoni; Severa, Gianmarco; Malfatti, Edoardo (May 2023). "Metabolic Myopathies in the Era of Next-Generation Sequencing". Genes. 14 (5): 954. doi: 10.3390/genes14050954 . ISSN   2073-4425. PMC   10217901 . PMID   37239314.
  2. 1 2 3 4 Tobon, Alejandro (December 2013). "Metabolic myopathies". Continuum (Minneapolis, Minn.). 19 (6 Muscle Disease): 1571–97. doi:10.1212/01.CON.0000440660.41675.06. ISSN   1538-6899. PMC   10563931 . PMID   24305448.
  3. Stegelmeier BL, Molyneux RJ, Elbein AD, James LF (May 1995). "The lesions of locoweed (Astragalus mollissimus), swainsonine, and castanospermine in rats". Veterinary Pathology. 32 (3): 289–98. doi : 10.1177/030098589503200311 PMID 7604496. S2CID 45016726.
  4. 1 2 3 "Metabolic Myopathy". www.hopkinsmedicine.org. Retrieved 2019-11-19.
  5. 1 2 Berardo A, DiMauro S, Hirano M (March 2010). "A diagnostic algorithm for metabolic myopathies". Current Neurology and Neuroscience Reports. 10 (2): 118–126. doi:10.1007/s11910-010-0096-4. PMC   2872126 . PMID   20425236.
  6. Bhagavan, N.V.; Ha, Chung-Eun (2015). "25. Nucleotide Metabolism § Myoadenylate Deaminase Deficiency". Essentials of Medical Biochemistry (2nd ed.). Elsevier. pp. 465–487. doi:10.1016/B978-0-12-416687-5.00025-7. ISBN   978-0-12-416687-5.
  7. 1 2 3 4 5 6 7 8 9 10 Wakelin A (2017). Living With McArdle Disease (PDF). IAMGSD (International Association for Muscle Glycogen Disease). p. 15.
  8. 1 2 3 4 5 6 Bhai, S. (September 2021). "Neuromuscular Notes: Diagnosing Metabolic Myopathies". Practical Neurology. Retrieved 2023-07-30.
  9. 1 2 3 4 Noury JB, Zagnoli F, Petit F, Marcorelles P, Rannou F (May 2020). "Exercise efficiency impairment in metabolic myopathies". Sci Rep. 10 (1): 8765. Bibcode:2020NatSR..10.8765N. doi:10.1038/s41598-020-65770-y. PMC   7260200 . PMID   32472082.
  10. 1 2 Saltin, Bengt (2000). "Ch. 21. Circulatory Regulation in Muscle Disease". Exercise and Circulation in Health and Disease. Human Kinetics. pp. 271–9. ISBN   978-0-88011-632-9.
  11. 1 2 3 4 5 6 7 Lucia A, Martinuzzi A, Nogales-Gadea G, Quinlivan R, Reason S (December 2021). "Clinical practice guidelines for glycogen storage disease V & VII (McArdle disease and Tarui disease) from an international study group". Neuromuscular Disorders. 31 (12): 1296–1310. doi: 10.1016/j.nmd.2021.10.006 . PMID   34848128.
  12. Chen, Yuxi; Hagen, Michael; Lawandy, Marco; Yu, Jessi (2017-03-09). "Congenital and Acquired Myotonia". PM&R KnowledgeNow. Retrieved 2023-10-13.
  13. 1 2 Kishnani PS, Austin SL, Arn P, Bali DS, Boney A, Case LE, et al. (July 2010). "Glycogen storage disease type III diagnosis and management guidelines". Genetics in Medicine. 12 (7): 446–463. doi: 10.1097/GIM.0b013e3181e655b6 . PMID   20631546. S2CID   4609175.
  14. 1 2 3 Rodríguez-Gómez I, Santalla A, Díez-Bermejo J, Munguía-Izquierdo D, Alegre LM, Nogales-Gadea G, et al. (November 2018). "Non-osteogenic muscle hypertrophy in children with McArdle disease". Journal of Inherited Metabolic Disease. 41 (6): 1037–42. doi:10.1007/s10545-018-0170-7. hdl: 10578/19657 . PMID   29594644. S2CID   4394513.
  15. 1 2 3 Menon MS, Roopch PS, Kabeer KA, Shaji CV (July 2016). "Calf Muscle Hypertrophy in Late Onset Pompe's Disease". Archives of Medicine and Health Sciences. 4 (2): 251. doi: 10.4103/2321-4848.196188 . ISSN   2321-4848. S2CID   58424073.
  16. 1 2 Larsson, L. -E.; Linderholm, H.; Müller, R.; Ringqvist, T.; Sörnäs, R. (October 1964). "Hereditary metabolic myopathy with paroxysmal myoglobinuria due to abnormal glycolysis1". Journal of Neurology, Neurosurgery, and Psychiatry. 27 (5): 361–380. doi:10.1136/jnnp.27.5.361. ISSN   0022-3050. PMC   495765 . PMID   14213465.
  17. 1 2 "Metabolic Myopathies". www.rheumatology.org. Retrieved 2019-11-19.
  18. 1 2 3 4 5 Wakelin A (2013). 101 Tips For A Good Life With McArdle Disease (PDF). AGSD-UK.
  19. 1 2 "Metabolic Myopathies — Signs and Symptoms". Muscular Dystrophy Association. 2015-12-18. Retrieved 2019-11-19.
  20. 1 2 3 Darras BT, Friedman NR (February 2000). "Metabolic myopathies: a clinical approach; part I". Pediatric Neurology. 22 (2): 87–97. doi:10.1016/S0887-8994(99)00133-2. PMID   10738913.
  21. Kiani AK, Amato B, Maitz S, Nodari S, Benedetti S, Agostini F, et al. (November 2020). "Genetic test for Mendelian fatigue and muscle weakness syndromes". Acta Bio-Medica. 91 (13–S): e2020001. doi:10.23750/abm.v91i13-S.10642. PMC   8023128 . PMID   33170160.
  22. Baker JS, McCormick MC, Robergs RA (2010). "Interaction among Skeletal Muscle Metabolic Energy Systems during Intense Exercise". Journal of Nutrition and Metabolism. 2010: 905612. doi: 10.1155/2010/905612 . PMC   3005844 . PMID   21188163.
  23. 1 2 3 "lecture17, Energy, Use of ATP by Muscle Cells, Skeletal Muscle". www.uwyo.edu. February 18, 2005. Retrieved 2022-12-22.
  24. Ahmed, Syeda T.; Craven, Lyndsey; Russell, Oliver M.; Turnbull, Doug M.; Vincent, Amy E. (2018-10-01). "Diagnosis and Treatment of Mitochondrial Myopathies". Neurotherapeutics. 15 (4): 943–953. doi:10.1007/s13311-018-00674-4. ISSN   1878-7479. PMC   6277287 . PMID   30406383.
  25. Moraes, C T; Shanske, S; Tritschler, H J; Aprille, J R; Andreetta, F; Bonilla, E; Schon, E A; DiMauro, S (March 1991). "mtDNA depletion with variable tissue expression: a novel genetic abnormality in mitochondrial diseases". American Journal of Human Genetics. 48 (3): 492–501. ISSN   0002-9297. PMC   1682992 . PMID   1998336.
  26. Preisler, Nicolai; Cohen, Jonathan; Vissing, Christoffer Rasmus; Madsen, Karen Lindhardt; Heinicke, Katja; Sharp, Lydia Jane; Phillips, Lauren; Romain, Nadine; Park, Sun Young; Newby, Marta; Wyrick, Phil; Mancias, Pedro; Galbo, Henrik; Vissing, John; Haller, Ronald Gerald (2017-11-01). "Impaired glycogen breakdown and synthesis in phosphoglucomutase 1 deficiency". Molecular Genetics and Metabolism. 122 (3): 117–121. doi:10.1016/j.ymgme.2017.08.007. ISSN   1096-7192. PMID   28882528.
  27. 1 2 Bonnet D, Martin D, Villain E, Jouvet P, Rabier D, Brivet M, Saudubray JM (November 1999). "Arrhythmias and conduction defects as presenting symptoms of fatty acid oxidation disorders in children". Circulation. 100 (22): 2248–53. doi: 10.1161/01.CIR.100.22.2248 . PMID   10577999.
  28. 1 2 Marbini A, Gemignani F, Saccardi F, Rimoldi M (October 1989). "Debrancher deficiency neuromuscular disorder with pseudohypertrophy in two brothers". Journal of Neurology. 236 (7): 418–420. doi:10.1007/BF00314902. PMID   2809644. S2CID   21158814.
  29. 1 2 Hokezu Y, Nagamatsu K, Nakagawa M, Osame M, Ohnishi A (June 1983). "[Glycogenosis type III with peripheral nerve disorder and muscular hypertrophy in an adult]". Rinsho Shinkeigaku = Clinical Neurology. 23 (6): 473–9. PMID   6317246.
  30. Walters, Jon (October 2017). "Muscle hypertrophy and pseudohypertrophy". Practical Neurology. 17 (5): 369–379. doi: 10.1136/practneurol-2017-001695 . ISSN   1474-7766. PMID   28778933.
  31. 1 2 Straub V, Murphy A, Udd B (August 2018). "229th ENMC international workshop: Limb girdle muscular dystrophies — Nomenclature and reformed classification Naarden, the Netherlands, 17-19 March 2017". Neuromuscular Disorders. 28 (8): 702–710. doi:10.1016/j.nmd.2018.05.007. hdl: 10138/305127 . PMID   30055862. S2CID   51865029.
  32. 1 2 Bisceglia L, Zoccolella S, Torraco A, Piemontese MR, Dell'Aglio R, Amati A, et al. (June 2010). "A new locus on 3p23-p25 for an autosomal-dominant limb-girdle muscular dystrophy, LGMD1H". European Journal of Human Genetics. 18 (6): 636–641. doi:10.1038/ejhg.2009.235. PMC   2987336 . PMID   20068593.
  33. Crooks, Daniel R.; Natarajan, Thanemozhi G.; Jeong, Suh Young; Chen, Chuming; Park, Sun Young; Huang, Hongzhan; Ghosh, Manik C.; Tong, Wing-Hang; Haller, Ronald G.; Wu, Cathy; Rouault, Tracey A. (2014-01-01). "Elevated FGF21 secretion, PGC-1α and ketogenic enzyme expression are hallmarks of iron–sulfur cluster depletion in human skeletal muscle". Human Molecular Genetics. 23 (1): 24–39. doi:10.1093/hmg/ddt393. ISSN   0964-6906. PMC   3857942 . PMID   23943793.
  34. "Primary Mitochondrial Myopathies — Symptoms, Causes, Treatment | NORD". rarediseases.org. Retrieved 2024-05-13.
  35. 1 2 Hagberg, J. M.; King, D. S.; Rogers, M. A.; Montain, S. J.; Jilka, S. M.; Kohrt, W. M.; Heller, S. L. (April 1990). "Exercise and recovery ventilatory and VO2 responses of patients with McArdle's disease". Journal of Applied Physiology. 68 (4): 1393–8. doi:10.1152/jappl.1990.68.4.1393. ISSN   8750-7587. PMID   2347781.
  36. 1 2 Hagberg, J. M.; Coyle, E. F.; Carroll, J. E.; Miller, J. M.; Martin, W. H.; Brooke, M. H. (April 1982). "Exercise hyperventilation in patients with McArdle's disease". Journal of Applied Physiology: Respiratory, Environmental and Exercise Physiology. 52 (4): 991–4. doi:10.1152/jappl.1982.52.4.991. ISSN   0161-7567. PMID   6953061.
  37. 1 2 Rodriguez-Lopez, Carlos; Santalla, Alfredo; Valenzuela, Pedro L.; Real-Martínez, Alberto; Villarreal-Salazar, Mónica; Rodriguez-Gomez, Irene; Pinós, Tomàs; Ara, Ignacio; Lucia, Alejandro (February 2023). "Muscle glycogen unavailability and fat oxidation rate during exercise: Insights from McArdle disease". The Journal of Physiology. 601 (3): 551–566. doi:10.1113/JP283743. ISSN   1469-7793. PMC   10099855 . PMID   36370371.
  38. Mineo, I.; Kono, N.; Hara, N.; Shimizu, T.; Yamada, Y.; Kawachi, M.; Kiyokawa, H.; Wang, Y. L.; Tarui, S. (1987-07-09). "Myogenic hyperuricemia. A common pathophysiologic feature of glycogenosis types III, V, and VII". The New England Journal of Medicine. 317 (2): 75–80. doi:10.1056/NEJM198707093170203. ISSN   0028-4793. PMID   3473284.
  39. 1 2 Hogrel, Jean-Yves; Janssen, Jorien B. E.; Ledoux, Isabelle; Ollivier, Gwenn; Béhin, Anthony; Stojkovic, Tanya; Eymard, Bruno; Voermans, Nicol C.; Laforet, Pascal (October 2017). "The diagnostic value of hyperammonaemia induced by the non-ischaemic forearm exercise test" (PDF). Journal of Clinical Pathology. 70 (10): 896–8. doi:10.1136/jclinpath-2017-204324. ISSN   1472-4146. PMID   28400468 via HAL.
  40. Echaniz-Laguna, Andoni; Lornage, Xavière; Laforêt, Pascal; Orngreen, Mette C.; Edelweiss, Evelina; Brochier, Guy; Bui, Mai T.; Silva-Rojas, Roberto; Birck, Catherine; Lannes, Béatrice; Romero, Norma B.; Vissing, John; Laporte, Jocelyn; Böhm, Johann (August 2020). "A New Glycogen Storage Disease Caused by a Dominant PYGM Mutation". Annals of Neurology. 88 (2): 274–282. doi:10.1002/ana.25771. ISSN   1531-8249. PMID   32386344.
  41. 1 2 Baker, Joshua J; Burton, Barbara K (November 2021). "Diagnosis and Clinical Management of Long-chain Fatty-acid Oxidation Disorders: A Review". TouchREVIEWS in Endocrinology. 17 (2): 108–111. doi:10.17925/EE.2021.17.2.108. ISSN   2752-5457. PMC   8676101 . PMID   35118456.
  42. Ventura, F. V.; Ruiter, J. P.; IJlst, L.; de Almeida, I. T.; Wanders, R. J. (August 1998). "Lactic acidosis in long-chain fatty acid beta-oxidation disorders". Journal of Inherited Metabolic Disease. 21 (6): 645–654. doi:10.1023/a:1005480516801. ISSN   0141-8955. PMID   9762600.
  43. 1 2 3 4 5 6 7 8 Reason SL, Voermans N, Lucia A, Vissing J, Quinlivan R, Bhai S, Wakelin A (July 2023). "Development of Continuum of Care for McArdle disease: A practical tool for clinicians and patients". Neuromuscular Disorders. 33 (7): 575–9. doi: 10.1016/j.nmd.2023.05.006 . PMID   37354872.
  44. van Loon LJ, Greenhaff PL, Constantin-Teodosiu D, Saris WH, Wagenmakers AJ (October 2001). "The effects of increasing exercise intensity on muscle fuel utilisation in humans". The Journal of Physiology. 536 (Pt 1): 295–304. doi:10.1111/j.1469-7793.2001.00295.x. PMC   2278845 . PMID   11579177.
  45. Scalco RS, Lucia A, Santalla A, Martinuzzi A, Vavla M, Reni G, et al. (November 2020). "Data from the European registry for patients with McArdle disease and other muscle glycogenoses (EUROMAC)". Orphanet Journal of Rare Diseases. 15 (1): 330. doi: 10.1186/s13023-020-01562-x . PMC   7687836 . PMID   33234167.
  46. 1 2 Løkken N, Hansen KK, Storgaard JH, Ørngreen MC, Quinlivan R, Vissing J (July 2020). "Titrating a modified ketogenic diet for patients with McArdle disease: A pilot study". J Inherit Metab Dis. 43 (4): 778–786. doi:10.1002/jimd.12223. PMID   32060930.
  47. 1 2 Reason SL (2013). One Step at a Time: Walking with McArdle Disease (PDF). AGSD-UK. ISBN   978-0-9569658-3-7.
  48. Scalco RS, Morrow JM, Booth S, Chatfield S, Godfrey R, Quinlivan R (September 2017). "Misdiagnosis is an important factor for diagnostic delay in McArdle disease". Neuromuscular Disorders. 27 (9): 852–5. doi: 10.1016/j.nmd.2017.04.013 . PMID   28629675.
  49. Das AM, Steuerwald U, Illsinger S (2010). "Inborn errors of energy metabolism associated with myopathies". J Biomed Biotechnol. 2010: 340849. doi: 10.1155/2010/340849 . PMC   2877206 . PMID   20589068.
  50. Clinical trial number NCT04694547 for "Ketogenic Diet Survey in Patients With McArdle Disease (GSDV)" at ClinicalTrials.gov
  51. 1 2 Kitaoka Y (February 2014). "McArdle Disease and Exercise Physiology". Biology. 3 (1): 157–166. doi: 10.3390/biology3010157 . PMC   4009758 . PMID   24833339.
  52. 1 2 3 4 5 6 Salazar-Martínez E, Santalla A, Valenzuela PL, Nogales-Gadea G, Pinós T, Morán M, et al. (2021). "The Second Wind in McArdle Patients: Fitness Matters". Frontiers in Physiology. 12: 744632. doi: 10.3389/fphys.2021.744632 . PMC   8555491 . PMID   34721068.
  53. Sanders, Lisa; M.D (2018-04-11). "What Is Causing This Woman's Severe Muscle Pain?". The New York Times. ISSN   0362-4331 . Retrieved 2024-05-13.
  54. "Angel's Story On 'Diagnosis' Will Warm Your Heart In Unimaginable Ways". Romper. 2024-02-20. Retrieved 2024-05-13.
  55. Jessop, Edmund (2015). "Walking with McArdle disease: alienation and solidarity in a rare disease journey". Rare Diseases and Orphan Drugs. 2 (3): 45–48.
  56. "Charity Walk Over Wales reaches the halfway point". County Times. 2010-07-22. Retrieved 2024-05-13.
  57. "IAMGSD | Get involved | Go on a course". iamgsd. Retrieved 2024-05-13.
  58. "GSD5 Section 3 Tab 5". AGSD-UK. 2018-11-29. Retrieved 2024-05-13.
  59. "Mattie Stepanek dies at 13". NBC News. 2004-06-23. Retrieved 2024-05-13.
  60. Hayman, John (May 2013). "Charles Darwin's Mitochondria". Genetics. 194 (1): 21–25. doi:10.1534/genetics.113.151241. ISSN   0016-6731. PMC   3632469 . PMID   23633139.

Further reading