Loss-of-function short coding mutations in SOX5
. (a) Pedigree of the family investigated in this study. SOX5
mutational status is shown below each tested family member. Symbols are as follows: circles, females; squares, males; filled, phenotypically abnormal; empty, healthy; slash, deceased. (b) Dideoxy sequencing traces document SOX5
c.13C>T (p.Arg5X) in genomic DNA of the index patient II-2 and her son III-1. Individuals I-2 and III-2 show homozygous wild-type sequence at this site. Arrows indicate the mutant nucleotide positions. (c) Schematic overview of the human SOX5
locus (NM_152989.3; top) and its encoded protein (NP_694534.1; bottom) illustrates the newly identified c.13C>T (p.Arg5X) stop-gain variant (boxed) and a loss-of-function point mutation previously described [6
]. Notably, all of the critical SOX-5 protein domains are distal to the p.Arg5X protein-truncation site and thus the truncated protein, if expressed, is highly unlikely to retain residual function. The schematic is simplified and not drawn to exact scale.