Three novel mutations of the PHEX gene in three Chinese families with X-linked dominant hypophosphatemic rickets.
X-linked dominant hypophosphatemia (XLH, OMIM307800), the most prevalent form of inherited rickets in humans, is a dominant disorder of phosphate homeostasis characterized by growth retardation, rachitic and osteomalacic bone disease, hypophosphatemia, and renal phosphate wasting. The gene responsible for XLH was identified by positional cloning and designated PHEX (formerly PEX) to depict a phosphate-regulating gene homologous with endopeptidases on the X chromosome. Recently, extensive mutation analysis of the PHEX gene has revealed a wide variety of gene defects in XLH. The ethnic distribution of the mutations is very widespread but only a few mutations in Chinese have been reported. To analyze the molecular basis in three unrelated Chinese families with XLH, we determined the nucleotide sequence of the PHEX gene and fibroblast growth factor 23 (FGF23) gene of affected members. The serum FGF23 concentrations of these patients with XLH were also measured. Three different novel mutations were observed in these three families: one deletion mutation c.264delG causing p.W88 X; one missense mutation c.1673C>G causing p.P558A; one nonsense mutation c.1809G>A causing p.W603 X. Serum concentration of FGF23 in XLH patients of these three families was significantly higher than normal. The results suggest that PHEX gene mutations were responsible for XLH in these patients and these mutations may contribute to a higher serum FGF23 level.
Xia
Weibo
W
Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, 100730, China. xiaweibo@medmail.com.cn
Meng
Xunwu
X
Jiang
Yan
Y
Li
Mei
M
Xing
Xiaoping
X
Pang
Li
L
Wang
Ou
O
Pei
Yu
Y
Yu
Li-Yun
LY
Sun
Yue
Y
Hu
Yingying
Y
Zhou
Xueying
X
D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D002681:China; D053098:Familial Hypophosphatemic Rickets / Q000235:genetics*; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood; D040181:Genetic Diseases, X-Linked; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D053402:PHEX Phosphate Regulating Neutral Endopeptidase / Q000235:genetics*; D010375:Pedigree; D017422:Sequence Analysis, DNA
C000717427:FGF23 protein, human; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D053402:PHEX Phosphate Regulating Neutral Endopeptidase; C506231:PHEX protein, human