Limb–girdle muscular dystrophy or (LGMD) is a genetically and clinically heterogeneous group of rare muscular dystrophies. It is characterised by progressive muscle wasting which affects predominantly hip and shoulder muscles. LGMD has an autosomal pattern of inheritance and currently has no known cure or treatment.
Spinal muscular atrophies (SMAs) are a genetically and clinically heterogeneous group of rare debilitating disorders characterised by the degeneration of lower motor neurons and subsequent atrophy (wasting) of various muscle groups in the body. While some SMAs lead to early infant death, other diseases of this group permit normal adult life with only mild weakness.
Spinal and bulbar muscular atrophy (SBMA), popularly known as Kennedy's disease, is a progressive debilitating neurodegenerative disorder resulting in muscle cramps and progressive weakness due to degeneration of motor neurons in the brainstem and spinal cord.
Progressive muscular atrophy (PMA) is a very rare subtype of motor neuron disease (MND) that affects only the lower motor neurons. PMA is thought to account for around 4% of all MND cases. This is in contrast to amyotrophic lateral sclerosis (ALS), the most common form of MND, which affects both the upper and lower motor neurons, or primary lateral sclerosis, another rare MND variant, which affects only the upper motor neurons. The distinction is important because PMA is associated with a better prognosis than classic ALS.
Spinal muscular atrophy (SMA) is a rare neuromuscular disorder that results in the loss of motor neurons and progressive muscle wasting. It is usually diagnosed in infancy or early childhood and if left untreated it is the most common genetic cause of infant death. It may also appear later in life and then have a milder course of the disease. The common feature is progressive weakness of voluntary muscles, with arm, leg and respiratory muscles being affected first. Associated problems may include poor head control, difficulties swallowing, scoliosis, and joint contractures.
Dejerine–Sottas disease, also known as, Dejerine–Sottas neuropathy, progressive hypertrophic interstitial polyneuropathy of childhood and onion bulb neuropathy, is a hereditary neurological disorder characterised by damage to the peripheral nerves and resulting progressive muscle wasting. The condition is caused by mutations in a various genes and currently has no known cure.
Episodic ataxia (EA) is an autosomal dominant disorder characterized by sporadic bouts of ataxia with or without myokymia. There are seven types recognized but the majority are due to two recognized entities. Ataxia can be provoked by psychological stress or startle, or heavy exertion, including exercise. Symptoms can first appear in infancy. There are at least six loci for EA, of which 4 are known genes. Some patients with EA also have migraine or progressive cerebellar degenerative disorders, symptomatic of either familial hemiplegic migraine or spinocerebellar ataxia. Some patients respond to acetazolamide though others do not.
Glycine—tRNA ligase also known as glycyl–tRNA synthetase is an enzyme that in humans is encoded by the GARS1 gene.
Cytoplasmic dynein 1 heavy chain 1 is a protein that in humans is encoded by the DYNC1H1 gene.
X-linked spinal muscular atrophy type 2, also known as arthrogryposis multiplex congenita X-linked type 1 (AMCX1), is a rare neurological disorder involving death of motor neurons in the anterior horn of spinal cord resulting in generalised muscle wasting (atrophy). The disease is caused by a mutation in UBA1 gene and is passed in an X-linked recessive manner by carrier mothers to affected sons.
Distal spinal muscular atrophy type 1 (DSMA1), also known as spinal muscular atrophy with respiratory distress type 1 (SMARD1), is a rare neuromuscular disorder involving death of motor neurons in the spinal cord which leads to a generalised progressive atrophy of body muscles.
Collagen VI (ColVI) is a type of collagen primarily associated with the extracellular matrix of skeletal muscle. ColVI maintains regularity in muscle function and stabilizes the cell membrane. It is synthesized by a complex, multistep pathway that leads to the formation of a unique network of linked microfilaments located in the extracellular matrix (ECM). ColVI plays a vital role in numerous cell types, including chondrocytes, neurons, myocytes, fibroblasts, and cardiomyocytes. ColVI molecules are made up of three alpha chains: α1(VI), α2(VI), and α3(VI). It is encoded by 6 genes: COL6A1, COL6A2, COL6A3, COL6A4, COL6A5, and COL6A6. The chain lengths of α1(VI) and α2(VI) are about 1,000 amino acids. The chain length of α3(VI) is roughly a third larger than those of α1(VI) and α2(VI), and it consists of several spliced variants within the range of 2,500 to 3,100 amino acids.
Spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME), sometimes called Jankovic–Rivera syndrome, is a very rare neurodegenerative disease whose symptoms include slowly progressive muscle wasting (atrophy), predominantly affecting proximal muscles, combined with denervation and myoclonic seizures. Only 12 known families are described in scientific literature to have SMA-PME.
Congenital distal spinal muscular atrophy is a hereditary condition characterized by muscle wasting (atrophy), particularly of distal muscles in legs and hands, and by early-onset contractures of the hip, knee, and ankle. Affected individuals often have shorter lower limbs relative to the trunk and upper limbs. The condition is a result of a loss of anterior horn cells localized to lumbar and cervical regions of the spinal cord early in infancy, which in turn is caused by a mutation of the TRPV4 gene. The disorder is inherited in an autosomal dominant manner. Arm muscle and function, as well as cardiac and respiratory functions are typically well preserved.
Distal spinal muscular atrophy type 2 (DSMA2), also known as Jerash type distal hereditary motor neuropathy (HMNJ), is a very rare childhood-onset genetic disorder characterised by progressive muscle wasting affecting lower and subsequently upper limbs. The disorder has been described in Arab inhabitants of Jerash region in Jordan as well as in a Chinese family.
Coiled-coil-helix-coiled-coil-helix domain-containing protein 10, mitochondrial, also known as Protein N27C7-4 is a protein that in humans is encoded by the CHCHD10 gene.
Distal hereditary motor neuropathy type V is a particular type of neuropathic disorder. In general, distal hereditary motor neuropathies affect the axons of distal motor neurons and are characterized by progressive weakness and atrophy of muscles of the extremities. It is common for them to be called "spinal forms of Charcot-Marie-Tooth disease (CMT)", because the diseases are closely related in symptoms and genetic cause. The diagnostic difference in these diseases is the presence of sensory loss in the extremities. There are seven classifications of dHMNs, each defined by patterns of inheritance, age of onset, severity, and muscle groups involved. Type V is a disorder characterized by autosomal dominance, weakness of the upper limbs that is progressive and symmetrical, and atrophy of the small muscles of the hands.
Spinal muscular atrophy with lower extremity predominance 2A (SMALED2A) is a rare neuromuscular disorder characterised by muscle weakness predominantly in legs. The disorder is usually diagnosed shortly after birth; affected children have a delayed motor development, waddling gait, difficulties walking, sometimes develop spasticity. Sensation, swallowing and cognitive development are not affected. The disorder is slowly progressive throughout the lifetime.
Spinal muscular atrophy with lower extremity predominance, sometimes called lower extremity-predominant spinal muscular atrophy, may refer to:
Spinal muscular atrophy with lower extremity predominance 2B (SMALED2B) is a rare neuromuscular disorder characterised by generalised muscle weakness.
