Fig. 1.

Nonsyndromic profound deafness is diagnosed in affected individuals who are homozygous for a GRAP variant. (A) Pedigrees and segregation of the GRAP c.311A>T variant in families 1 and 2. (B) Hearing thresholds obtained from pure tone audiograms of the affected individuals showing severe to profound HL. Unaffected individuals display normal hearing. Ages indicated are at the time of the audiograms. (C) Electropherograms showing the identified variant. The wild-type (WT) traces are from an unrelated individual. Hom, homozygous mutant, Het, heterozygous mutant. (D) Amino acid sequences of the partial SH2 domain of GRAP in different species. Amino acid Gln104 (Q104) is highly conserved in mammals.