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GENATLAS PHENOTYPE
last update : 19-08-2009
Symbol DFNA20
Location 17q25
HGNC id 2793
Name neurosensory deafness 20
Corresponding gene ACTG1
Other symbol(s) DFNA26
Main clinical features
  • non syndromic, post lingual, progressive, with marked decreases in their ability to hear high frequency sounds ranging from 4 to 8 kHz, overlapping DFNA26 region
  • later progresses to affect the entire frequency range
    • Genetic determination autosomal dominant
    Function/system disorder ear
    Type disease
    Gene product
    Name actin, gamma 1
    Mechanism(s)
    Gene mutationChromosome rearrangementEffectComments
    various types   abnormal protein/loss of function altered ability of the actin filaments to be properly regulated by actin-binding proteins rather than an inability to polymerize
    missense   abnormal protein/loss of function Thr278Ile
    Remark(s)
  • mutations, although they seem to not drastically affect polymerization, can cause a range of allele-specific effects of the ability of actin to be properly regulated by an actin-binding protein (Bryan 2009)
  • E241K mutation were remarkable in that the mutation also led to the abnormal formation of thick randomly oriented actin filament bundles and associated with very severe phenotype (Morin 2009)