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GENATLAS PHENOTYPE
last update : 06/12/2009
Symbol MEAX
Location Xq28
HGNC id 22082
Name myopathy with excessive autophagy
Corresponding gene VMA21
Other symbol(s) XMEA
Main clinical features
  • is a skeletal muscle disorder inherited in recessive fashion, affecting boys and sparing carrier females
  • weakness of the proximal muscles of the lower extremities, progressing slowly to involve other skeletal muscle groups
  • myofiber demise occurs through a form of autophagic cell death
  • vacuolar myopathy spearing cardiac muscle and central nervous system, congenital hypotonia, dyspnea, and dysphagia withdelayed motor milestones
  • at the muscular biopsy, autophagic vacuoles with sarcolemmal features, multilayered basal lamina with marked sarcolemmal deposition of C5-9 membrane attack complex and calcium
  • childhood-onset disease characterized by progressive vacuolation and atrophy of skeletal muscle
    • Genetic determination sex linked
    Function/system disorder neuromuscular
    Type disease
    Gene product
    Name VMA21 vacuolar H+-ATPase homolog Vacuolar ATPase assembly integral membrane protein VMA21
    Mechanism(s)
    Gene mutationChromosome rearrangementEffectComments
    various types   under-expression XMEA is caused by hypomorphic alleles of the VMA21 gene
    Remark(s)