A novel CHSY1 gene mutation underlies Temtamy preaxial brachydactyly syndrome in a Pakistani family.

Temtamy preaxial brachydactyly syndrome (TPBS) is an autosomal recessive rare disorder characterized by hyperphalangism of digits, facial dysmorphism, dental anomalies, sensorineural hearing loss, delayed motor and mental development, and growth retardation. Loss of function mutations have been recently reported in the CHSY1 gene to cause the TPBS. Here, we report a novel missense mutation (c.1897 G > A) in the CHSY1 gene in two TPBS patients from a consanguineous Pakistani family. The mutation predicted substitution of a highly conserved aspartate amino acid residue to asparagine at position 633 in the protein (D633N). Polyphen analysis supported the pathogenicity of D36N mutation. Our finding extends the body of recent evidence that supports the role of CHSY1 as a potential mediator of BMP signaling.