Non-random distribution of mutations in the PHEX gene, and under-detected missense mutations at non-conserved residues

Thirty newly detected mutations in the PHEX gene are reported, and pooled with all the previously published mutations, The spectrum of mutations displayed 16% deletions, 8% insertions, 34% missense, 27% nonsense, and 15% splice site mutations, with two peaks in exon 15, and 17, Since 32.8% of PHEX amino acids were conserved in the endopeptidases family, the number of missense mutations detected at non-conserved residues was smaller than expected, whereas the number of nonsense mutations observed at non-conserved residues was very close to the expected number, Compared with conserved amino acids, the changes in nonconserved amino acids may result in benign polymorphisms or possibly mild disease that may go undiagnosed.