ClinVar

Description

Variant summary: NF1 c.4986C>T alters a non-conserved nucleotide resulting in a synonymous change. 5/5 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant was observed with an allele frequency of 0.0001191 in 277132 control chromosomes (gnomAD). The observed variant frequency within Ashkenazi Jewish control individuals in the gnomAD database is approximately 8-folds higher than the estimated maximal expected allele frequency for a pathogenic variant in NF1 causing Neurofibromatosis Type 1 phenotype (0.00021), strongly suggesting that the variant is a benign polymorphism found primarily in population(s) of Ashkenazi Jewish origin. To our knowledge, no occurrence of c.4986C>T in individuals affected with Neurofibromatosis Type 1 and no experimental evidence demonstrating its impact on protein function have been reported. Multiple ClinVar submissions from clinical diagnostic laboratories (evaluation after 2014) cite the variant as "benign." Based on the evidence outlined above, the variant was classified as benign.