Fig. 2

The genetic analysis of the family. (A) Sanger DNA sequencing chromatogram demonstrates the heterozygosity for a CTC1 missense mutation (c.391G > A/ p.Gly131Arg) in the family. (B) Alignment of multiple CTC1 protein sequences across species. The Gly131 affected amino acid locates in the highly conserved amino acid region in different mammals (from Ensembl). Red column shows the Gly131 site. (C) The wild type CTC1 (WT) protein structure and the mutant CTC1 (p.G131R) protein structure were predicted by SWISS-MODEL online software. The hydrophobic surface area, surface charge and polarity of the WT and mutated CTC1 were predicted. (D) Telomere length of the mutation carriers (II-1 and II-3) and healthy family member (II-5).