ClinVar

Description

Variant summary: ALMS1 c.9819C>G (also known as c.9825C>G) alters a non-conserved nucleotide resulting in a synonymous change. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.0023 in 249364 control chromosomes, predominantly at a frequency of 0.0029 within the Non-Finnish European subpopulation in the gnomAD database. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database is approximately 1.3 fold of the estimated maximal expected allele frequency for a pathogenic variant in ALMS1 causing Cardiomyopathy phenotype (0.0022), strongly suggesting that the variant is a benign polymorphism found primarily in populations of Non-Finnish European origin. To our knowledge, no occurrence of c.9819C>G in individuals affected with Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (2x Benign/likely benign ; 1x uncertain significance). Based on the evidence outlined above, the variant was classified as benign.