Research Information System
13th Balkan Congress of Human Genetics, Edirne, Turkey, 17 - 20 April 2019, pp.38
Introduction and Aim X-linked hypophosphatemic rickets, inherited in a dominant manner, is the most common form of familial hypophosphatemic rickets. Clinical manifestations of XLHR can vary but most patients will present with limb deformity, primarily affecting the legs and short stature. A 2-year-old boy presented to us with a complaint of curvature of the legs. Physical examination revealed pectus carinatum and genu varum deformity. His mother had short stature and hypochondroplasic-disproportional body view. Biochemical blood measures were as follows: ALP:827 U/L, iP:2.6 mg/dL, PTH:107.1 pg/mL, calcium:10.37 mg/dL. We aimed to contribute to the literature by sharing the novel mutation of PHEX gene we found in our case. Material and Method With peripheral blood sample, the FGFR3 and PHEX genes were analyzed by sequence analysis and next generation sequencing (NGS) method respectively. Results FGFR3 gene sequence analysis revealed a heterozygous c.1082-13C>T alterati n in the intr n 8, near the ‘’splice site’’. His m ther had the same alteration; his brother without symptoms also had the mutation. Later, PHEX gene analysis revealed a hemizygous c.436+1G>T splice donor novel mutation in the intron 4. Discussion The phenotypic spectrum of XLHR ranges from isolated hypophosphatemia to severe lower-extremity bowing. The clinic of our case was compatible with this disease. Initially, the alteration in the FGRF3 gene suggested that it could not cause phenotype in our case because it was detected in the healthy brother. By showing a novel mutation in the PHEX gene, we highlighted the diagnosis of XLHR.
KEYWORDS: PHEX, hypophosphatemic rickets , NOVEL, NGS