In the present study, novel mutations p.D175A and p.G269R were
found as compound heterozygous in infantile TSD. The missense mutation
p.D175A disrupts the β-sheet due to an amino acid change from a
positively charged aspartic acid to a hydrophobic alanine residue at
codon 175 of exon 5. At the same time, p.G269R mutation creates
over-packing and backbone disruption due to the replacement of a
small hydrophilic group (glycine) with a positively charged residue (Alanine)
at codon 269 of exon-7 [Fig. 2(a)–(b)]. Therefore, disruption of
the backbone from αGly269Arg may result in the movement of
αHis262, with the likelihood of disrupting the coordination of residues
in the active site. The RMSD of the modeled mutant is also significantly