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Easy fatigability

MedGen UID:
373253
Concept ID:
C1837098
Finding
Synonym: Tired easily
 
HPO: HP:0003388

Definition

Increased susceptibility to fatigue. [from HPO]

Term Hierarchy

Conditions with this feature

Diaphyseal dysplasia
MedGen UID:
4268
Concept ID:
C0011989
Finding
Camurati-Engelmann disease (CED) is characterized by hyperostosis of the long bones and the skull, proximal muscle weakness, limb pain, a wide-based, waddling gait, and joint contractures. Facial features such as macrocephaly, frontal bossing, enlargement of the mandible, proptosis, and cranial nerve impingement resulting in facial palsy are seen in severely affected individuals later in life.
Glycogen storage disease, type VII
MedGen UID:
5342
Concept ID:
C0017926
Disease or Syndrome
Glycogen storage disease VII is an autosomal recessive metabolic disorder characterized clinically by exercise intolerance, muscle cramping, exertional myopathy, and compensated hemolysis. Myoglobinuria may also occur. The deficiency of the muscle isoform of PFK results in a total and partial loss of muscle and red cell PFK activity, respectively. Raben and Sherman (1995) noted that not all patients with GSD VII seek medical care because in some cases it is a relatively mild disorder.
Autosomal recessive limb-girdle muscular dystrophy type 2K
MedGen UID:
332193
Concept ID:
C1836373
Disease or Syndrome
Limb-girdle muscular dystrophies resulting from defective glycosylation of alpha-dystroglycan (DAG1; 128239) represent the mildest end of the phenotypic spectrum of muscular dystrophies collectively known as dystroglycanopathies. The limb-girdle phenotype is characterized by onset of muscular weakness apparent after ambulation is achieved; mental retardation and mild brain anomalies are variable (Balci et al., 2005; review by Godfrey et al., 2007). The most severe end of the phenotypic spectrum of dystroglycanopathies is represented by congenital muscular dystrophy-dystroglycanopathy with brain and eye anomalies (type A; see MDDGA1, 236670), previously designated Walker-Warburg syndrome (WWS) or muscle-eye-brain disease (MEB), and the intermediate range of the spectrum is represented by congenital muscular dystrophy-dystroglycanopathy with or without mental retardation (type B; see MDDGB1, 613155). Genetic Heterogeneity of Limb-Girdle Muscular Dystrophy-Dystroglycanopathy (Type C) Limb-girdle muscular dystrophy due to defective glycosylation of DAG1 is genetically heterogeneous. See also MDDGC2 (613158), caused by mutation in the POMT2 gene (607439); MDDGC3 (613157), caused by mutation in the POMGNT1 gene (606822); MDDGC4 (611588), caused by mutation in the FKTN gene (607440); MDDGC5 (607155), caused by mutation in the FKRP gene (606596); MDDGC7 (616052), caused by mutation in the ISPD gene (CRPPA; 614631); MDDGC8 (618135), caused by mutation in the POMGNT2 gene (614828); MDDGC9 (613818) caused by mutation in the DAG1 gene (128239); MDDGC12 (616094), caused by mutation in the POMK gene (615247); MDDGC14 (615352) caused by mutation in the GMPPB gene (615320); and MDDGC15 (612937), caused by mutation in the DPM3 gene (605951).
Congenital myasthenic syndrome 4C
MedGen UID:
373251
Concept ID:
C1837091
Disease or Syndrome
Congenital myasthenic syndrome associated with AChR deficiency is a disorder of the postsynaptic neuromuscular junction (NMJ) clinically characterized by early-onset muscle weakness with variable severity. Electrophysiologic studies show low amplitude of the miniature endplate potential (MEPP) and current (MEPC) resulting from deficiency of AChR at the endplate. Patients with mutations in the CHRNE gene may have compensatory increased expression of the fetal subunit CHRNG (100730) and may respond to treatment with cholinergic agents, pyridostigmine, or amifampridine (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Nemaline myopathy 2
MedGen UID:
342534
Concept ID:
C1850569
Disease or Syndrome
Nemaline myopathy-2 (NEM2) is an autosomal recessive skeletal muscle disorder with a wide range of severity. The most common clinical presentation is early-onset (in infancy or childhood) muscle weakness predominantly affecting proximal limb muscles. Muscle biopsy shows accumulation of Z-disc and thin filament proteins into aggregates named 'nemaline bodies' or 'nemaline rods,' usually accompanied by disorganization of the muscle Z discs. The clinical and histologic spectrum of entities caused by variants in the NEB gene is a continuum, ranging in severity. The distribution of weakness can vary from generalized muscle weakness, more pronounced in proximal limb muscles, to distal-only involvement, although neck flexor weakness appears to be rather consistent. Histologic patterns range from a severe usually nondystrophic disturbance of the myofibrillar pattern to an almost normal pattern, with or without nemaline bodies, sometimes combined with cores (summary by Lehtokari et al., 2014). Genetic Heterogeneity of Nemaline Myopathy See also NEM1 (255310), caused by mutation in the tropomyosin-3 gene (TPM3; 191030) on chromosome 1q22; NEM3 (161800), caused by mutation in the alpha-actin-1 gene (ACTA1; 102610) on chromosome 1q42; NEM4 (609285), caused by mutation in the beta-tropomyosin gene (TPM2; 190990) on chromosome 9p13; NEM5A (605355), also known as Amish nemaline myopathy, NEM5B (620386), and NEM5C (620389), all caused by mutation in the troponin T1 gene (TNNT1; 191041) on chromosome 19q13; NEM6 (609273), caused by mutation in the KBTBD13 gene (613727) on chromosome 15q22; NEM7 (610687), caused by mutation in the cofilin-2 gene (CFL2; 601443) on chromosome 14q13; NEM8 (615348), caused by mutation in the KLHL40 gene (615340), on chromosome 3p22; NEM9 (615731), caused by mutation in the KLHL41 gene (607701) on chromosome 2q31; NEM10 (616165), caused by mutation in the LMOD3 gene (616112) on chromosome 3p14; and NEM11 (617336), caused by mutation in the MYPN gene (608517) on chromosome 10q21. Several of the genes encode components of skeletal muscle sarcomeric thin filaments (Sanoudou and Beggs, 2001). Mutations in the NEB gene are the most common cause of nemaline myopathy (Lehtokari et al., 2006).
Hereditary myopathy with lactic acidosis due to ISCU deficiency
MedGen UID:
342573
Concept ID:
C1850718
Disease or Syndrome
Hereditary myopathy with lactic acidosis (HML) is an autosomal recessive muscular disorder characterized by childhood onset of exercise intolerance with muscle tenderness, cramping, dyspnea, and palpitations. Biochemical features include lactic acidosis and, rarely, rhabdomyolysis. It is a chronic disorder with remission and exacerbation of the muscle phenotype (summary by Sanaker et al., 2010).
Congenital myasthenic syndrome 10
MedGen UID:
376880
Concept ID:
C1850792
Disease or Syndrome
Congenital myasthenic syndromes (CMS) are a group of inherited disorders affecting the neuromuscular junction (NMJ). Patients present clinically with onset of variable muscle weakness between infancy and adulthood. These disorders have been classified according to the location of the defect: presynaptic, synaptic, and postsynaptic. CMS10 is an autosomal recessive CMS resulting from a postsynaptic defect affecting endplate maintenance of the NMJ. Patients present with limb-girdle weakness in the first decade. Treatment with ephedrine or salbutamol may be beneficial; cholinesterase inhibitors should be avoided (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Neutral lipid storage myopathy
MedGen UID:
339913
Concept ID:
C1853136
Disease or Syndrome
Neutral lipid storage disease with myopathy (NLSDM) is an autosomal recessive muscle disorder characterized by adult onset of slowly progressive proximal muscle weakness affecting the upper and lower limbs and associated with increased serum creatine kinase; distal muscle weakness may also occur. About half of patients develop cardiomyopathy later in the disease course. Other variable features include diabetes mellitus, hepatic steatosis, hypertriglyceridemia, and possibly sensorineural hearing loss. Leukocytes and muscle cells show cytoplasmic accumulation of triglycerides (summary by Reilich et al., 2011). Neutral lipid storage disease with myopathy belongs to a group of disorders termed neutral lipid storage disorders (NLSDs). These disorders are characterized by the presence of triglyceride-containing cytoplasmic droplets in leukocytes and in other tissues, including bone marrow, skin, and muscle. Chanarin-Dorfman syndrome (CDS; 275630) is defined as NLSD with ichthyosis (NLSDI). Patients with NLSDM present with myopathy but without ichthyosis (summary by Fischer et al., 2007).
Sengers syndrome
MedGen UID:
395228
Concept ID:
C1859317
Disease or Syndrome
Sengers syndrome is an autosomal recessive mitochondrial disorder characterized by congenital cataracts, hypertrophic cardiomyopathy, skeletal myopathy, exercise intolerance, and lactic acidosis. Mental development is normal, but affected individuals may die early from cardiomyopathy (summary by Mayr et al., 2012). Skeletal muscle biopsies of 2 affected individuals showed severe mtDNA depletion (Calvo et al., 2012).
Congenital myasthenic syndrome 5
MedGen UID:
400481
Concept ID:
C1864233
Disease or Syndrome
Congenital myasthenic syndromes (CMS) are a group of inherited disorders affecting the neuromuscular junction. Patients present clinically with onset of variable muscle weakness between infancy and adulthood. These disorders have been classified according to the location of the defect: presynaptic, synaptic, and postsynaptic. Endplate acetylcholinesterase deficiency is an autosomal recessive congenital myasthenic syndrome characterized by a defect within the synapse at the neuromuscular junction (NMJ). Mutations in COLQ result in a deficiency of acetylcholinesterase (AChE), which causes prolonged synaptic currents and action potentials due to extended residence of acetylcholine in the synaptic space. Treatment with ephedrine may be beneficial; AChE inhibitors and amifampridine should be avoided (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Myofibrillar myopathy 6
MedGen UID:
414119
Concept ID:
C2751831
Disease or Syndrome
Myofibrillar myopathy-6 is an autosomal dominant severe neuromuscular disorder characterized by onset in the first decade of rapidly progressive generalized and proximal muscle weakness, respiratory insufficiency, cardiomyopathy, and skeletal deformities related to muscle weakness. Muscle biopsy shows fiber-type grouping, disruption of the Z lines, and filamentous inclusions, and sural nerve biopsy shows a neuropathy, often with giant axonal neurons. Most patients are severely affected by the second decade and need cardiac transplant, ventilation, and/or a wheelchair (summary by Jaffer et al., 2012). For a phenotypic description and a discussion of genetic heterogeneity of myofibrillar myopathy (MFM), see MFM1 (601419).
Neuronopathy, distal hereditary motor, type 2C
MedGen UID:
461969
Concept ID:
C3150619
Disease or Syndrome
Any neuronopathy, distal hereditary motor in which the cause of the disease is a mutation in the HSPB3 gene.
Congenital myasthenic syndrome 16
MedGen UID:
481742
Concept ID:
C3280112
Disease or Syndrome
Congenital myasthenic syndrome is a disorder characterized by variable degrees of muscle fatigability caused by impaired transmission of electrical signals at the neuromuscular junction (NMJ) (summary by Arnold et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Congenital myasthenic syndrome 12
MedGen UID:
765249
Concept ID:
C3552335
Disease or Syndrome
Congenital myasthenic syndrome-12 is an autosomal recessive neuromuscular disorder characterized by onset of proximal muscle weakness in the first decade. EMG classically shows a decremental response to repeated nerve stimulation. Affected individuals show a favorable response to acetylcholinesterase (AChE) inhibitors (summary by Senderek et al., 2011). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Mitochondrial DNA depletion syndrome 11
MedGen UID:
767376
Concept ID:
C3554462
Disease or Syndrome
Mitochondrial DNA depletion syndrome-11 is an autosomal recessive mitochondrial disorder characterized by onset in childhood or adulthood of progressive external ophthalmoplegia (PEO), muscle weakness and atrophy, exercise intolerance, and respiratory insufficiency due to muscle weakness. More variable features include spinal deformity, emaciation, and cardiac abnormalities. Skeletal muscle biopsies show deletion and depletion of mitochondrial DNA (mtDNA) with variable defects in respiratory chain enzyme activities (summary by Kornblum et al., 2013). For a discussion of genetic heterogeneity of autosomal recessive mtDNA depletion syndromes, see MTDPS1 (603041).
Congenital myasthenic syndrome 8
MedGen UID:
815069
Concept ID:
C3808739
Disease or Syndrome
Congenital myasthenic syndromes are genetic disorders of the neuromuscular junction (NMJ) that are classified by the site of the transmission defect: presynaptic, synaptic, and postsynaptic. CMS8 is an autosomal recessive disorder characterized by prominent defects of both the pre- and postsynaptic regions. Affected individuals have onset of muscle weakness in early childhood; the severity of the weakness and muscles affected is variable (summary by Maselli et al., 2012). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Mitochondrial DNA depletion syndrome 12B (cardiomyopathic type), autosomal recessive
MedGen UID:
815773
Concept ID:
C3809443
Disease or Syndrome
Mitochondrial DNA depletion syndrome-12B is an autosomal recessive mitochondrial disorder characterized by childhood onset of slowly progressive hypertrophic cardiomyopathy and generalized skeletal myopathy resulting in exercise intolerance, and, in some patients, muscle weakness and atrophy. Skeletal muscle biopsy shows ragged-red fibers, mtDNA depletion, and accumulation of abnormal mitochondria (summary by Echaniz-Laguna et al., 2012). For a discussion of genetic heterogeneity of mtDNA depletion syndromes, see MTDPS1 (603041).
Proximal myopathy with extrapyramidal signs
MedGen UID:
816615
Concept ID:
C3810285
Disease or Syndrome
Myopathy with extrapyramidal signs is an autosomal recessive disorder characterized by early childhood onset of proximal muscle weakness and learning disabilities. While the muscle weakness is static, most patients develop progressive extrapyramidal signs that may become disabling (summary by Logan et al., 2014). Brain MRI in 1 patient showed congenital malformations, including polymicrogyria and cerebellar dysplasia (Wilton et al., 2020).
Myopathy, tubular aggregate, 1
MedGen UID:
860163
Concept ID:
C4011726
Disease or Syndrome
Tubular aggregates in muscle, first described by Engel (1964), are structures of variable appearance consisting of an outer tubule containing either one or more microtubule-like structures or amorphous material. They are a nonspecific pathologic finding that may occur in a variety of circumstances, including alcohol- and drug-induced myopathies, exercise-induced cramps or muscle weakness, and inherited myopathies. Tubular aggregates are derived from the sarcoplasmic reticulum (Salviati et al., 1985) and are believed to represent an adaptive mechanism aimed at regulating an increased intracellular level of calcium in order to prevent the muscle fibers from hypercontraction and necrosis (Martin et al., 1997; Muller et al., 2001). Genetic Heterogeneity of Tubular Aggregate Myopathy See also TAM2 (615883), caused by mutation in the ORAI1 gene (610277) on chromosome 12q24.
Congenital myasthenic syndrome 7
MedGen UID:
863475
Concept ID:
C4015038
Disease or Syndrome
Presynaptic congenital myasthenic syndrome-7A with distal motor neuropathy (CMS7A) is an autosomal dominant neuromuscular disorder characterized by onset of foot deformities, delayed motor development, and slowly progressive distal muscle weakness resulting in gait difficulties in early childhood. Other features may include hyporeflexia, muscle atrophy, and upper limb involvement. Electrophysiologic studies show low compound muscle action potentials (CMAPs), consistent with a distal hereditary motor neuropathy (dHMN), as well as a decremental response to repetitive stimulation, indicating presynaptic defects at the neuromuscular junction (NMJ), consistent with myasthenic syndrome (summary by Fionda et al., 2021). The complex phenotype of patients with dominant SYT2 mutations likely results from impairment of 2 fundamental functions of SYT2: (1) disturbance of calcium-dependent synchronous presynaptic neurotransmitter release, resulting in a myasthenic disorder, and (2) disruption of exocytosis and endocytosis, causing a degenerative process affecting peripheral motor nerve terminals and resulting in a motor neuropathy (Maselli et al., 2021). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462). For a discussion of genetic heterogeneity of dHMN, see 182960.
Autosomal recessive spinocerebellar ataxia 17
MedGen UID:
863738
Concept ID:
C4015301
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-17 (SCAR17) is a neurologic disorder characterized by onset of gait ataxia and cerebellar signs in early childhood. Patients also have variably impaired intellectual development (summary by Evers et al., 2016).
Myopathy due to calsequestrin and SERCA1 protein overload
MedGen UID:
864061
Concept ID:
C4015624
Disease or Syndrome
Vacuolar myopathy with CASQ1 aggregates is an autosomal dominant mild muscle disorder characterized by adult onset of muscle cramping and weakness as well as increased levels of serum creatine kinase (CK). The disorder is not progressive, and some patients may be asymptomatic (summary by Rossi et al., 2014).
Combined oxidative phosphorylation defect type 24
MedGen UID:
864080
Concept ID:
C4015643
Disease or Syndrome
Combined oxidative phosphorylation deficiency-24 (COXPD24) is an autosomal recessive mitochondrial disorder with wide phenotypic variability. Most patients present in infancy with delayed neurodevelopment, refractory seizures, hypotonia, and hearing impairment due to auditory neuropathy. Less common features may include cortical blindness, renal dysfunction, and/or liver involvement, suggestive of Alpers syndrome (MTDPS4A; 203700). Patients with the severe phenotype tend to have brain abnormalities on imaging, including cerebral atrophy and hyperintensities in the basal ganglia and brainstem, consistent with Leigh syndrome. Laboratory values may be normal or show increased lactate and evidence of mitochondrial respiratory chain defects, particularly in muscle. Some patients achieve little developmental milestones and may die in infancy or early childhood. However, some patients have a less severe phenotype manifest only by myopathy (summary by Sofou et al., 2015, Vanlander et al., 2015, and Mizuguchi et al., 2017). For a discussion of genetic heterogeneity of combined oxidative phosphorylation deficiency, see COXPD1 (609060).
Charcot-Marie-Tooth disease type 4K
MedGen UID:
895560
Concept ID:
C4225246
Disease or Syndrome
Charcot-Marie-Tooth disease type 4K is an autosomal recessive demyelinating peripheral neuropathy characterized by onset in the first decade of distal muscle weakness and atrophy associated with impaired distal sensation. Both upper and lower limbs are affected. Affected individuals may also have nystagmus and late-onset cerebellar ataxia. Laboratory studies show increased serum lactate and isolated mitochondrial complex IV deficiency (summary by Echaniz-Laguna et al., 2013). For a phenotypic description and a discussion of genetic heterogeneity of autosomal recessive demyelinating Charcot-Marie-Tooth disease, see CMT4A (214400).
Congenital myasthenic syndrome 11
MedGen UID:
902189
Concept ID:
C4225367
Disease or Syndrome
Congenital myasthenic syndrome associated with AChR deficiency is a disorder of the postsynaptic neuromuscular junction (NMJ) clinically characterized by early-onset muscle weakness with variable severity. Electrophysiologic studies show low amplitude of the miniature endplate potential (MEPP) and current (MEPC) resulting from deficiency of AChR at the endplate. Treatment with cholinesterase inhibitors or amifampridine may be helpful (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Congenital myasthenic syndrome 9
MedGen UID:
895641
Concept ID:
C4225368
Disease or Syndrome
Congenital myasthenic syndrome associated with AChR deficiency is a disorder of the postsynaptic neuromuscular junction (NMJ) clinically characterized by early-onset muscle weakness with variable severity. Electrophysiologic studies show low amplitude of the miniature endplate potential (MEPP) and current (MEPC) resulting from deficiency of AChR at the endplate. Patients may show a favorable response to amifampridine (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Congenital myasthenic syndrome 4B
MedGen UID:
904424
Concept ID:
C4225369
Disease or Syndrome
Fast-channel congenital myasthenic syndrome (FCCMS) is a disorder of the postsynaptic neuromuscular junction (NMJ) characterized by early-onset progressive muscle weakness. The disorder results from kinetic abnormalities of the AChR channel, specifically from abnormally brief opening and activity of the channel, with a rapid decay in endplate current and a failure to reach the threshold for depolarization. Treatment with pyridostigmine or amifampridine may be helpful; quinine, quinidine, and fluoxetine should be avoided (summary by Sine et al., 2003 and Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Congenital myasthenic syndrome 3B
MedGen UID:
909404
Concept ID:
C4225371
Disease or Syndrome
Fast-channel congenital myasthenic syndrome (FCCMS) is a disorder of the postsynaptic neuromuscular junction (NMJ) characterized by early-onset progressive muscle weakness. The disorder results from kinetic abnormalities of the acetylcholine receptor channel, specifically from abnormally brief opening and activity of the channel, with a rapid decay in endplate current and a failure to reach the threshold for depolarization. Treatment with pyridostigmine or amifampridine may be helpful; quinine, quinidine, and fluoxetine should be avoided (summary by Sine et al., 2003 and Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Congenital myasthenic syndrome 3A
MedGen UID:
898378
Concept ID:
C4225372
Disease or Syndrome
Slow-channel congenital myasthenic syndrome (SCCMS) is a disorder of the postsynaptic neuromuscular junction (NMJ) characterized by early-onset progressive muscle weakness. The disorder results from kinetic abnormalities of the AChR channel, specifically from prolonged opening and activity of the channel, which causes prolonged synaptic currents resulting in a depolarization block. This is associated with calcium overload, which may contribute to subsequent degeneration of the endplate and postsynaptic membrane. Treatment with quinine, quinidine, or fluoxetine may be helpful; acetylcholinesterase inhibitors and amifampridine should be avoided (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Congenital myasthenic syndrome 2A
MedGen UID:
908185
Concept ID:
C4225374
Disease or Syndrome
Slow-channel congenital myasthenic syndrome (SCCMS) is a disorder of the postsynaptic neuromuscular junction (NMJ) characterized by early-onset progressive muscle weakness. The disorder results from kinetic abnormalities of the acetylcholine receptor channel, specifically from prolonged opening and activity of the channel, which causes prolonged synaptic currents resulting in a depolarization block. This is associated with calcium overload, which may contribute to subsequent degeneration of the endplate and postsynaptic membrane. Treatment with quinine, quinidine, or fluoxetine may be helpful; cholinesterase inhibitors and amifampridine should be avoided (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Myasthenic syndrome, congenital, 1B, fast-channel
MedGen UID:
909200
Concept ID:
C4225405
Disease or Syndrome
Fast-channel congenital myasthenic syndrome (FCCMS) is a disorder of the postsynaptic neuromuscular junction (NMJ) characterized by early-onset progressive muscle weakness. The disorder results from kinetic abnormalities of the acetylcholine receptor (AChR) channel, specifically from abnormally brief opening and activity of the channel, with a rapid decay in endplate current and a failure to reach the threshold for depolarization. Treatment with pyridostigmine or amifampridine may be helpful; quinine, quinidine, and fluoxetine should be avoided (summary by Sine et al., 2003 and Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Congenital myasthenic syndrome 4A
MedGen UID:
908188
Concept ID:
C4225413
Disease or Syndrome
Slow-channel congenital myasthenic syndrome (SCCMS) is a disorder of the postsynaptic neuromuscular junction (NMJ) characterized by early-onset progressive muscle weakness. The disorder results from kinetic abnormalities of the acetylcholine receptor channel, specifically from prolonged opening and activity of the channel, which causes prolonged synaptic currents resulting in a depolarization block. This is associated with calcium overload, which may contribute to subsequent degeneration of the endplate and postsynaptic membrane. Treatment with quinine, quinidine, or fluoxetine may be helpful; acetylcholinesterase inhibitors and amifampridine should be avoided (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Myofibrillar myopathy 8
MedGen UID:
934612
Concept ID:
C4310645
Disease or Syndrome
Myofibrillar myopathy-8 (MFM8) is an autosomal recessive myopathy characterized by slowly progressive proximal muscle weakness and atrophy affecting the upper and lower limbs, resulting in increased falls, gait problems, difficulty running or climbing stairs, and upper limb weakness or scapular winging. Some patients develop distal muscle weakness and atrophy. The phenotype may also be consistent with a clinical diagnosis of limb-girdle muscular dystrophy (LGMD). Age at symptom onset ranges from infancy to adulthood. Ambulation is generally preserved and cardiac involvement is rare, but respiratory compromise with decreased forced vital capacity often occurs. Muscle biopsy shows a mix of myopathic features, including myofibrillar inclusions and sarcomeric disorganization; some patients have been reported to have dystrophic changes on muscle biopsy (O'Grady et al., 2016; Daimaguler et al., 2021). There is significant phenotypic variation, even in patients with the same mutation, which must be taken into account when counseling affecting individuals (Woods et al., 2020). For a general phenotypic description and a discussion of genetic heterogeneity of myofibrillar myopathy, see MFM1 (601419).
Congenital myasthenic syndrome 21
MedGen UID:
934621
Concept ID:
C4310654
Disease or Syndrome
Any congenital myasthenic syndrome in which the cause of the disease is a mutation in the SLC18A3 gene.
Immunodeficiency, developmental delay, and hypohomocysteinemia
MedGen UID:
1616061
Concept ID:
C4540293
Disease or Syndrome
IMDDHH is a multisystem disorder characterized by immunodeficiency, mildly delayed psychomotor development, poor overall growth from infancy, and hypohomocysteinemia. Additional features, such as congenital heart defects and liver involvement, are more variable (summary by Huppke et al., 2017).
Myopathy, centronuclear, 6, with fiber-type disproportion
MedGen UID:
1627492
Concept ID:
C4540345
Disease or Syndrome
Centronuclear myopathy-6 with fiber-type disproportion (CNM6) is an autosomal recessive, slowly progressive congenital myopathy with onset in infancy or early childhood. Patients may be hypotonic at birth, but all show delayed motor development and walking difficulties due to muscle weakness mainly affecting the proximal lower and upper limbs. Other features include scapular winging, scoliosis, and mildly decreased respiratory vital capacity. The phenotype and muscle biopsy abnormalities are variable, although centralized nuclei and fiber-type disproportion appear to be a common finding on muscle biopsy (summary by Vasli et al., 2017). For a discussion of genetic heterogeneity of centronuclear myopathy, see CNM1 (160150).
Autosomal dominant centronuclear myopathy
MedGen UID:
1645741
Concept ID:
C4551952
Disease or Syndrome
Centronuclear myopathy-1 (CNM1) is an autosomal dominant congenital myopathy characterized by slowly progressive muscular weakness and wasting. The disorder involves mainly limb girdle, trunk, and neck muscles but may also affect distal muscles. Weakness may be present during childhood or adolescence or may not become evident until the third decade of life, and some affected individuals become wheelchair-bound in their fifties. Ptosis and limitation of eye movements occur frequently. The most prominent histopathologic features include high frequency of centrally located nuclei in a large number of extrafusal muscle fibers (which is the basis of the name of the disorder), radial arrangement of sarcoplasmic strands around the central nuclei, and predominance and hypotrophy of type 1 fibers (summary by Bitoun et al., 2005). Genetic Heterogeneity of Centronuclear Myopathy Centronuclear myopathy is a genetically heterogeneous disorder. See also X-linked CNM (CNMX; 310400), caused by mutation in the MTM1 gene (300415) on chromosome Xq28; CNM2 (255200), caused by mutation in the BIN1 gene (601248) on chromosome 2q14; CNM4 (614807), caused by mutation in the CCDC78 gene (614666) on chromosome 16p13; CNM5 (615959), caused by mutation in the SPEG gene (615950) on chromosome 2q35; and CNM6 (617760), caused by mutation in the ZAK gene (609479) on chromosome 2q31. The mutation in the MYF6 gene that was reported to cause a form of CNM, formerly designated CNM3, has been reclassified as a variant of unknown significance; see 159991.0001. Some patients with mutation in the RYR1 gene (180901) have findings of centronuclear myopathy on skeletal muscle biopsy (see 255320).
Osteochondrodysplasia, brachydactyly, and overlapping malformed digits
MedGen UID:
1648332
Concept ID:
C4748496
Disease or Syndrome
Osteochondrodysplasia, brachydactyly, and overlapping malformed digits (OCBMD) is characterized by bilateral symmetric skeletal defects that primarily affect the limbs. Affected individuals have mild short stature due to shortening of the lower leg bones, as well as hand and foot malformations, predominantly brachydactyly and overlapping digits. Other skeletal defects include scoliosis, dislocated patellae and fibulae, and pectus excavatum (Shabbir et al., 2018).
Myasthenic syndrome, congenital, 23, presynaptic
MedGen UID:
1648392
Concept ID:
C4748678
Disease or Syndrome
Mitochondrial complex 1 deficiency, nuclear type 29
MedGen UID:
1648451
Concept ID:
C4748830
Disease or Syndrome
Spinocerebellar ataxia, autosomal recessive 23
MedGen UID:
1667331
Concept ID:
C4750914
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-23 is a neurologic disorder characterized by epilepsy, intellectual disability, and gait ataxia (summary by Gomez-Herreros et al., 2014).
Metabolic crises, recurrent, with variable encephalomyopathic features and neurologic regression
MedGen UID:
1681269
Concept ID:
C5193083
Disease or Syndrome
Recurrent metabolic crises with variable encephalomyopathic features and neurologic regression (MECREN) is an autosomal recessive metabolic disorder with a highly variable phenotype. Most affected individuals present in the first years of life with episodic lactic acidosis associated with illness or stress, resulting in transient or permanent neurologic dysfunction. Some patients may recover, whereas others show subsequent variable developmental regression of motor and cognitive skills. Other features may include dystonia, hypotonia with inability to sit or walk, seizures, and abnormal signals in the basal ganglia. There is significant phenotypic heterogeneity, even among patients with the same mutation (summary by Almannai et al., 2018).
Myasthenic syndrome, congenital, 7B, presynaptic, autosomal recessive
MedGen UID:
1794157
Concept ID:
C5561947
Disease or Syndrome
Autosomal recessive presynaptic congenital myasthenic syndrome-7B (CMS7B) is characterized by severe generalized muscle weakness apparent from birth; decreased fetal movements may be apparent in utero. Affected infants have generalized hypotonia with poor cry and feeding, head lag, and facial muscle weakness with ptosis. Some patients may have respiratory involvement. Electrophysiologic studies show decreased compound muscle action potentials (CMAPs) and a decremental response to repetitive nerve stimulation. Treatment with 3,4-diaminopyridine and pyridostigmine may result in clinical improvement (summary by Bauche et al., 2020).
Pulmonary hypertension, primary, autosomal recessive
MedGen UID:
1802382
Concept ID:
C5676877
Disease or Syndrome
Primary pulmonary hypertension-5 (PPH5) is an autosomal recessive disorder characterized by the onset of pulmonary arterial hypertension in infancy, resulting in right heart dysfunction and ultimately right heart failure. Death in early childhood is common (Machado et al., 2022). For a discussion of genetic heterogeneity of primary pulmonary hypertension, see PPH1 (178600).
Thyroid hormone metabolism, abnormal, 3
MedGen UID:
1824065
Concept ID:
C5774292
Disease or Syndrome
Abnormal thyroid hormone metabolism-3 (THMA3) is characterized by euthyroid hyperthyroxinemia, with elevated free T4 and reverse T3 levels, and normal TSH (see 188540) and free T3 levels. Patients also show low plasma selenium levels and reduced levels of stress-related selenoproteins (Schoenmakers et al., 2016; Geslot et al., 2021). For a discussion of genetic heterogeneity of abnormal thyroid hormone metabolism, see THMA1 (609698).

Professional guidelines

PubMed

Wu M, Liu C, Sun D
Horm Metab Res 2024 May;56(5):341-349. Epub 2024 Jan 15 doi: 10.1055/a-2246-2900. PMID: 38224966
Fung RCM, Hon KL, Leung AKC
Recent Pat Inflamm Allergy Drug Discov 2020;14(2):106-116. doi: 10.2174/1872213X14666200204103714. PMID: 32013855
Okano Y, Ohura T, Sakamoto O, Inui A
Mol Genet Metab 2019 Jul;127(3):175-183. Epub 2019 Jun 15 doi: 10.1016/j.ymgme.2019.06.004. PMID: 31255436

Recent clinical studies

Etiology

Henderson FC Sr, Austin C, Benzel E, Bolognese P, Ellenbogen R, Francomano CA, Ireton C, Klinge P, Koby M, Long D, Patel S, Singman EL, Voermans NC
Am J Med Genet C Semin Med Genet 2017 Mar;175(1):195-211. Epub 2017 Feb 21 doi: 10.1002/ajmg.c.31549. PMID: 28220607
Hoshino C, Satoh N, Narita M, Kikuchi A, Inoue M
BMJ Case Rep 2011 Apr 9;2011 doi: 10.1136/bcr.02.2011.3888. PMID: 22700935Free PMC Article
Ishaque S, Ahmed S, Ali R, Minhas K
J Coll Physicians Surg Pak 2011 Jul;21(7):434-6. PMID: 21777536
Church T
Obesity (Silver Spring) 2009 Dec;17 Suppl 3:S39-42. doi: 10.1038/oby.2009.387. PMID: 19927145
Tahir MH, Iqbal T, Raja MK
J Coll Physicians Surg Pak 2005 Jun;15(6):362-3. PMID: 15924843

Diagnosis

Wu M, Liu C, Sun D
Horm Metab Res 2024 May;56(5):341-349. Epub 2024 Jan 15 doi: 10.1055/a-2246-2900. PMID: 38224966
Van Hul W, Boudin E, Vanhoenacker FM, Mortier G
Calcif Tissue Int 2019 May;104(5):554-560. Epub 2019 Feb 5 doi: 10.1007/s00223-019-00532-1. PMID: 30721323
Henderson FC Sr, Austin C, Benzel E, Bolognese P, Ellenbogen R, Francomano CA, Ireton C, Klinge P, Koby M, Long D, Patel S, Singman EL, Voermans NC
Am J Med Genet C Semin Med Genet 2017 Mar;175(1):195-211. Epub 2017 Feb 21 doi: 10.1002/ajmg.c.31549. PMID: 28220607
Hoshino C, Satoh N, Narita M, Kikuchi A, Inoue M
BMJ Case Rep 2011 Apr 9;2011 doi: 10.1136/bcr.02.2011.3888. PMID: 22700935Free PMC Article
Taniegra ED
Am Fam Physician 2004 Jan 15;69(2):333-9. PMID: 14765772

Therapy

Wu M, Liu C, Sun D
Horm Metab Res 2024 May;56(5):341-349. Epub 2024 Jan 15 doi: 10.1055/a-2246-2900. PMID: 38224966
Sachin J, Shukla R, Anil A, Saravanan A, Santhyavu S, Varthya SB, Ambwani S, Singh S
J Med Case Rep 2023 Dec 15;17(1):542. doi: 10.1186/s13256-023-04279-0. PMID: 38098118Free PMC Article
Okano Y, Ohura T, Sakamoto O, Inui A
Mol Genet Metab 2019 Jul;127(3):175-183. Epub 2019 Jun 15 doi: 10.1016/j.ymgme.2019.06.004. PMID: 31255436
Van Hul W, Boudin E, Vanhoenacker FM, Mortier G
Calcif Tissue Int 2019 May;104(5):554-560. Epub 2019 Feb 5 doi: 10.1007/s00223-019-00532-1. PMID: 30721323
Tahir MH, Iqbal T, Raja MK
J Coll Physicians Surg Pak 2005 Jun;15(6):362-3. PMID: 15924843

Prognosis

Ma J, Zhang H, Pang X, Zhang J, Zhao R, Wang J, Chang X, Guo J, Zhang W
Muscle Nerve 2024 Feb;69(2):199-205. Epub 2023 Dec 21 doi: 10.1002/mus.28020. PMID: 38124677
Francini-Pesenti F, Vitturi N, Tresso S, Sorarù G
Rev Neurol (Paris) 2020 Dec;176(10):780-787. Epub 2020 Jul 4 doi: 10.1016/j.neurol.2020.03.020. PMID: 32631678
Ishaque S, Ahmed S, Ali R, Minhas K
J Coll Physicians Surg Pak 2011 Jul;21(7):434-6. PMID: 21777536
Tahir MH, Iqbal T, Raja MK
J Coll Physicians Surg Pak 2005 Jun;15(6):362-3. PMID: 15924843
Silverberg SJ
J Bone Miner Res 2002 Nov;17 Suppl 2:N117-25. PMID: 12412788

Clinical prediction guides

Ma J, Zhang H, Pang X, Zhang J, Zhao R, Wang J, Chang X, Guo J, Zhang W
Muscle Nerve 2024 Feb;69(2):199-205. Epub 2023 Dec 21 doi: 10.1002/mus.28020. PMID: 38124677
Akkan Suzan A, Kahraman Koytak P, Uluc K, Tanridag T
Acta Neurol Belg 2022 Aug;122(4):915-923. Epub 2022 Mar 25 doi: 10.1007/s13760-022-01919-y. PMID: 35334084
Onakpoya UU, Ojo OO, Eyekpegha OJ, Oguns AE, Akintomide AO
Pan Afr Med J 2020;36:177. Epub 2020 Jul 13 doi: 10.11604/pamj.2020.36.177.24425. PMID: 32952821Free PMC Article
Bebeshko VG, Bruslova KM, Volodina TT, Lyashenko LO, Tsvetkova NM, Trychlib IV, Chernysh TO, Boyarskiy VG, Gonchar LO, Kavardakova NV
Probl Radiac Med Radiobiol 2019 Dec;24:322-334. doi: 10.33145/2304-8336-2019-24-322-334. PMID: 31841477
Miike T, Tomoda A, Jhodoi T, Iwatani N, Mabe H
Brain Dev 2004 Oct;26(7):442-7. doi: 10.1016/j.braindev.2003.10.004. PMID: 15351079

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