ClinVar

Description

Variant summary: GAA c.368G>A (p.Gly123Glu) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00099 in 247744 control chromosomes, predominantly at a frequency of 0.0077 within the South Asian subpopulation in the gnomAD database, including 5 homozygotes. The observed variant frequency within South Asian control individuals in the gnomAD database is approximately 2 fold of the estimated maximal expected allele frequency for a pathogenic variant in GAA causing Glycogen Storage Disease, Type 2 (Pompe Disease) phenotype (0.0042), strongly suggesting that the variant is a benign polymorphism found primarily in populations of South Asian origin. To our knowledge, no occurrence of c.368G>A in individuals affected with Glycogen Storage Disease, Type 2 (Pompe Disease) and no experimental evidence demonstrating its impact on protein function have been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as benign/likely benign. Based on the evidence outlined above, the variant was classified as benign.