Fig. 1

Characterization of the TK2 compound heterozygous mutations in the patient. A Pedigree diagram of the family indicating the inheritance of the TK2 compound heterozygous mutations. B Sanger sequencing chromatograms showing the heterozygous c.311G > A mutation in the proband and the father (I-2). The large deletion mutation (E5–E10 del) in the proband was detected through MLPA, and this mutation was inherited from the patient's mother. C In silico prediction of the pathogenicity of the c.311G > A (p.Arg104His) mutation using the PolyPhen-2 software. The missense mutation is predicted to be "probably damaging". D Schematic of the TK2 protein structure a showing the location of the missense mutation (p.Arg104His) and the large deletion (E5–E10 del) mutation. Structural modeling b depicts the predicted impact of the p.Arg104His mutation on protein conformation. Structural modeling c shows the severe truncation resulting from the E5–E10 deletion