Adult polyglucosan body disease

Last updated
Adult polyglucosan disease
Other namesAFBD
Specialty Medical genetics

Adult polyglucosan body disease (APBD) is a rare genetic glycogen storage disorder caused by an inborn error of metabolism. Symptoms can emerge any time after the age of 30. Early symptoms include trouble controlling urination, trouble walking, lack of sensation in the legs and people eventually develop dementia.

Contents

A person inherits loss-of-function mutations in the GBE1 gene from each parent, and the lack of glycogen branching enzyme (the protein encoded by GBE1) leads to buildup of unbranched glycogen in cells, which harms neurons more than other kinds of cells.

Most people first go to the doctor due to trouble with urination. The condition is diagnosed by gathering symptoms, a neurological examination, laboratory tests including genetic testing, and medical imaging. As of 2015, there was no cure or treatment, but the symptoms could be managed. People diagnosed with APBD can live a long time after diagnosis, but will probably die earlier than people without the condition.

Signs and symptoms

Adult polyglucosan body disease is a condition that affects the nervous system. People with this condition have problems walking due to reduced sensation in their legs (peripheral neuropathy) and progressive muscle weakness and stiffness (spasticity). Damage to the nerves that control bladder function (neurogenic bladder) causes progressive difficulty in controlling the flow of urine. About half of people with adult polyglucosan body disease experience dementia. [1] Most people with the condition first complain of bladder issues. [2]

People with adult polyglucosan body disease typically first experience signs and symptoms related to the condition between ages 30 and 60. [1]

Causes

APBD is an autosomal recessive disorder that is caused when a person inherits genes from both parents containing one or more loss-of-function mutations in the gene GBE1 which encodes for glycogen branching enzyme, also called 1,4-alpha-glucan-branching enzyme. [3]

Mechanism

The GBE1 gene provides instructions for making the glycogen branching enzyme. This enzyme is involved in the production of a complex sugar called glycogen, which is a major source of stored energy in the body. Most GBE1 gene mutations result in a shortage (deficiency) of the glycogen branching enzyme, which leads to the production of abnormal glycogen molecules. These abnormal glycogen molecules, called polyglucosan bodies, accumulate within cells and cause damage. Neurons appear to be particularly vulnerable to the accumulation of polyglucosan bodies in people with this disorder, leading to impaired neuronal function. [1]

Some mutations in the GBE1 gene that cause adult polyglucosan body disease do not result in a shortage of glycogen branching enzyme. In people with these mutations, the activity of this enzyme is normal. How mutations cause the disease in these individuals is unclear. Other people with adult polyglucosan body disease do not have identified mutations in the GBE1 gene. In these individuals, the cause of the disease is unknown. [1]

Diagnosis

Along with evaluation of the symptoms and a neurological examination, a diagnosis can be made based on genetic testing. Whether or not a person is making sufficient amounts of functional glycogen branching enzyme can be determined by taking a skin biopsy and testing for activity of the enzyme. Examination of tissue biopsied from the sural nerve under a microscope can reveal the presence of polyglucosan bodies. There will also be white matter changes visible in a magnetic resonance imaging scans. [4]

Classification

Adult polyglucosan body disease is an orphan disease and a glycogen storage disorder that is caused by an inborn error of metabolism, that affects the central and peripheral nervous systems. [4] [5]

The condition in newborns caused by the same mutations is called glycogen storage disease type IV. [3]

Prevention

APBD can only be prevented if parents undergo genetic screening to understand their risk of producing a child with the condition; if in vitro fertilization is used, then preimplantation genetic diagnosis can be done to identify fertilized eggs that do not carry two copies of mutated GBE1. [4]

Management

As of 2015 there was no cure for APDB, instead symptoms are managed. [6] There are various approaches to managing neurogenic bladder dysfunction, physical therapy and mobility aids to help with walking, and dementia can be managed with occupational therapy, counseling and drugs. [3] Presently a number of promising research initiatives are underway in universities and hospitals in the United States, Canada, and Israel. These studies are in need of funding but due to the small number of known cases both research funding and participation is small. It is estimated that there are upwards of 12,000 cases in the United States, most of which are undiagnosed.[ citation needed ]

Outcomes

The rate of progression varies significantly from person to person. [4] [6]

There is not good data on outcomes; it appears that APBD likely leads to earlier death, but people with APBD can live many years after diagnosis with relatively good quality of life. [4]

Epidemiology

The prevalence is unknown; about 70 cases had been reported in the medical literature as of 2016. [1] As of 2016, the largest set of case studies included 50 people; about 70% of them were of Ashkenazic Jewish descent. [3] [7]

Society and culture

A person with APBD named Gregory Weiss created a foundation, the Adult Polyglucosan Body Disease Research Foundation, to fund research into the disease and its management. [2] [8]

Research directions

In 2015 the first transgenic mouse that appeared to be a useful model organism for studying APBD was published. [3]

Related Research Articles

Lafora disease is a rare, adult-onset and autosomal recessive genetic disorder which results in myoclonus epilepsy and usually results in death several years after the onset of symptoms. The disease is characterized by the accumulation of inclusion bodies, known as Lafora bodies, within the cytoplasm of the cells in the heart, liver, muscle, and skin. Lafora disease is also a neurodegenerative disease that causes impairment in the development of brain (cerebral) cortical neurons and is a glycogen metabolism disorder.

<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.

<span class="mw-page-title-main">Congenital insensitivity to pain with anhidrosis</span> Medical condition

Congenital insensitivity to pain with anhidrosis (CIPA) is a rare autosomal recessive disorder of the nervous system which prevents the feeling of pain or temperature, and prevents a person from sweating. Cognitive disorders are commonly coincident. CIPA is the fourth type of hereditary sensory and autonomic neuropathy (HSAN), and is also known as HSAN IV.

Inborn errors of metabolism form a large class of genetic diseases involving congenital disorders of enzyme activities. The majority are due to defects of single genes that code for enzymes that facilitate conversion of various substances (substrates) into others (products). In most of the disorders, problems arise due to accumulation of substances which are toxic or interfere with normal function, or due to the effects of reduced ability to synthesize essential compounds. Inborn errors of metabolism are often referred to as congenital metabolic diseases or inherited metabolic disorders. Another term used to describe these disorders is "enzymopathies". This term was created following the study of biodynamic enzymology, a science based on the study of the enzymes and their products. Finally, inborn errors of metabolism were studied for the first time by British physician Archibald Garrod (1857–1936), in 1908. He is known for work that prefigured the "one gene-one enzyme" hypothesis, based on his studies on the nature and inheritance of alkaptonuria. His seminal text, Inborn Errors of Metabolism, was published in 1923.

<span class="mw-page-title-main">Maple syrup urine disease</span> Autosomal recessive metabolic disorder

Maple syrup urine disease (MSUD) is an autosomal recessive metabolic disorder affecting branched-chain amino acids. It is one type of organic acidemia. The condition gets its name from the distinctive sweet odor of affected infants' urine and earwax, particularly prior to diagnosis and during times of acute illness. It was described by John Menkes in the 1950s.

<span class="mw-page-title-main">Glycogen storage disease type IV</span> Human disease

Glycogen storage disease type IV (GSD IV), or Andersen's Disease, is a form of glycogen storage disease, which is caused by an inborn error of metabolism. It is the result of a mutation in the GBE1 gene, which causes a defect in the glycogen branching enzyme. Therefore, glycogen is not made properly and abnormal glycogen molecules accumulate in cells; most severely in cardiac and muscle cells. The severity of this disease varies on the amount of enzyme produced. GSD IV is autosomal recessive, which means each parent has a mutant copy of the gene, but show no symptoms of the disease. Having an autosomal recessive inheritance pattern, males and females are equally likely to be affected by Andersen's disease. Classic Andersen's disease typically becomes apparent during the first few months after the patient is born. Approximately 1 in 20,000 to 25,000 newborns have a glycogen storage disease. Andersen's disease affects 1 in 800,000 individuals worldwide, with 3% of all GSDs being type IV. The disease was described and studied first by Dorothy Hansine Andersen.

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

Glycogen storage disease type III (GSD III) is an autosomal recessive metabolic disorder and inborn error of metabolism (specifically of carbohydrates) characterized by a deficiency in glycogen debranching enzymes. It is also known as Cori's disease in honor of the 1947 Nobel laureates Carl Cori and Gerty Cori. Other names include Forbes disease in honor of clinician Gilbert Burnett Forbes (1915–2003), an American physician who further described the features of the disorder, or limit dextrinosis, due to the limit dextrin-like structures in cytosol. Limit dextrin is the remaining polymer produced after hydrolysis of glycogen. Without glycogen debranching enzymes to further convert these branched glycogen polymers to glucose, limit dextrinosis abnormally accumulates in the cytoplasm.

<span class="mw-page-title-main">Glycogen branching enzyme</span> Mammalian protein involved in glycogen production

1,4-alpha-glucan-branching enzyme, also known as brancher enzyme or glycogen-branching enzyme is an enzyme that in humans is encoded by the GBE1 gene.

<span class="mw-page-title-main">MERRF syndrome</span> Medical condition

MERRF syndrome is a mitochondrial disease. It is extremely rare, and has varying degrees of expressivity owing to heteroplasmy. MERRF syndrome affects different parts of the body, particularly the muscles and nervous system. The signs and symptoms of this disorder appear at an early age, generally childhood or adolescence. The causes of MERRF syndrome are difficult to determine, but because it is a mitochondrial disorder, it can be caused by the mutation of nuclear DNA or mitochondrial DNA. The classification of this disease varies from patient to patient, since many individuals do not fall into one specific disease category. The primary features displayed on a person with MERRF include myoclonus, seizures, cerebellar ataxia, myopathy, and ragged red fibers (RRF) on muscle biopsy, leading to the disease's name. Secondary features include dementia, optic atrophy, bilateral deafness, peripheral neuropathy, spasticity, or multiple lipomata. Mitochondrial disorders, including MERRFS, may present at any age.

<span class="mw-page-title-main">Neuropathy, ataxia, and retinitis pigmentosa</span> Medical condition

Neuropathy, ataxia, and retinitis pigmentosa, also known as NARP syndrome, is a rare disease with mitochondrial inheritance that causes a variety of signs and symptoms chiefly affecting the nervous system Beginning in childhood or early adulthood, most people with NARP experience numbness, tingling, or pain in the arms and legs ; muscle weakness; and problems with balance and coordination (ataxia). Many affected individuals also have vision loss caused by changes in the light-sensitive tissue that lines the back of the eye. In some cases, the vision loss results from a condition called retinitis pigmentosa. This eye disease causes the light-sensing cells of the retina gradually to deteriorate.

<span class="mw-page-title-main">Mitochondrial neurogastrointestinal encephalopathy syndrome</span> Medical condition

Mitochondrial neurogastrointestinal encephalopathy syndrome (MNGIE) is a rare autosomal recessive mitochondrial disease. It has been previously referred to as polyneuropathy, ophthalmoplegia, leukoencephalopathy, and intestinal pseudoobstruction. The disease presents in childhood, but often goes unnoticed for decades. Unlike typical mitochondrial diseases caused by mitochondrial DNA (mtDNA) mutations, MNGIE is caused by mutations in the TYMP gene, which encodes the enzyme thymidine phosphorylase. Mutations in this gene result in impaired mitochondrial function, leading to intestinal symptoms as well as neuro-ophthalmologic abnormalities. A secondary form of MNGIE, called MNGIE without leukoencephalopathy, can be caused by mutations in the POLG gene.

Progressive Myoclonic Epilepsies (PME) are a rare group of inherited neurodegenerative diseases characterized by myoclonus, resistance to treatment, and neurological deterioration. The cause of PME depends largely on the type of PME. Most PMEs are caused by autosomal dominant or recessive and mitochondrial mutations. The location of the mutation also affects the inheritance and treatment of PME. Diagnosing PME is difficult due to their genetic heterogeneity and the lack of a genetic mutation identified in some patients. The prognosis depends largely on the worsening symptoms and failure to respond to treatment. There is no current cure for PME and treatment focuses on managing myoclonus and seizures through antiepileptic medication (AED).

<span class="mw-page-title-main">Beta-mannosidosis</span> Medical condition

Beta-mannosidosis, also called lysosomal beta-mannosidase deficiency, is a disorder of oligosaccharide metabolism caused by decreased activity of the enzyme beta-mannosidase. This enzyme is coded for by the gene MANBA, located at 4q22-25. Beta-mannosidosis is inherited in an autosomal recessive manner. Affected individuals appear normal at birth, and can have a variable clinical presentation. Infantile onset forms show severe neurodegeneration, while some children have intellectual disability. Hearing loss and angiokeratomas are common features of the disease.

<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.

Leukoencephalopathy with neuroaxonal spheroids (LENAS) is an extremely rare kind of leukoencephalopathy and is classified as a neurodegenerative disease. LENAS is a cause of severe and subacute dementia that results from damage to certain areas of the brain. This damage is to a type of brain tissue called white matter and axon damage due to swellings which are termed spheroids.

Hereditary sensory and autonomic neuropathy (HSAN) or hereditary sensory neuropathy (HSN) is a condition used to describe any of the types of this disease which inhibit sensation.

Danon disease is a metabolic disorder. Danon disease is an X-linked lysosomal and glycogen storage disorder associated with hypertrophic cardiomyopathy, skeletal muscle weakness, and intellectual disability. It is inherited in an X-linked dominant pattern.

<span class="mw-page-title-main">Lysosomal acid lipase deficiency</span> Medical condition

Lysosomal acid lipase deficiency is an autosomal recessive inborn error of metabolism that results in the body not producing enough active lysosomal acid lipase (LAL) enzyme. This enzyme plays an important role in breaking down fatty material in the body. Infants, children and adults that have LAL deficiency experience a range of serious health problems. The lack of the LAL enzyme can lead to a build-up of fatty material in a number of body organs including the liver, spleen, gut, in the wall of blood vessels and other important organs.

Autophagic vacuolar myopathy (AVM) consists of multiple rare genetic disorders with common histological and pathological features on muscle biopsy. The features highlighted are vacuolar membranes of the autophagic vacuoles having sarcolemmal characteristics and an excess of autophagic vacuoles. There are currently five types of AVM identified. The signs and symptoms become more severe over the course of the disease. It begins with an inability to pick up small objects and progresses to difficulty in walking. The age of onset varies from early childhood to late adulthood, affecting people of all ages.

Autosomal dominant cerebellar ataxia, deafness, and narcolepsy (ADCADN) is a rare progressive genetic disorder that primarily affects the nervous system and is characterized by sensorineural hearing loss, narcolepsy with cataplexy, and dementia later in life. People with this disorder usually start showing symptoms when they are in their early-mid adulthoods. It is a type of autosomal dominant cerebellar ataxia.

References

  1. 1 2 3 4 5 "Adult polyglucosan body disease". NIH Genetics Home Reference. July 2016. Retrieved 7 March 2017.
  2. 1 2 DiMauro, S; Spiegel, R (October 2011). "Progress and problems in muscle glycogenoses". Acta Myologica. 30 (2): 96–102. PMC   3235878 . PMID   22106711.
  3. 1 2 3 4 5 McKusick, Victor A.; Kniffin, Cassandra L. (May 2, 2016). "OMIM Entry 263570 - Polyglucosan body neuropathy, adult form". Online Mendelian Inheritance in Man. Johns Hopkins University. Retrieved 7 March 2017.
  4. 1 2 3 4 5 Klein, Christopher J. (December 19, 2013). "Adult Polyglucosan Body Disease". In Pagon, RA; et al. (eds.). GeneReviews. Seattle: University of Washington.
  5. "Adult polyglucosan body disease". Orphanet. September 2012. Retrieved 7 March 2017.
  6. 1 2 "Adult Polyglucosan Body Disease". NORD (National Organization for Rare Disorders). 2015. Retrieved 7 March 2017.
  7. Mochel; et al. (September 2012). "Adult polyglucosan body disease: Natural History and Key Magnetic Resonance Imaging Findings". Annals of Neurology. 72 (3): 433–41. doi:10.1002/ana.23598. PMC   4329926 . PMID   23034915.
  8. "Adult Polyglucosan Body Disease Research Foundation (APBDRF)" . Retrieved 7 March 2017.