An unusual case of familial hypophosphatemic rickets

Abstract

Rickets is the failure of mineralisation of osteoid and newly formed bones in a child skeleton. It is commonly associated with vitamin D deficiency; however, it can be because of a decrease in serum phosphate level leading to inadequate mineralization of cartilage and bone, consequent skeletal deformities and growth retardation. In hypophosphatemic rickets, there are both inherited and acquired forms, where X-linked hypophosphatemic rickets (XLH) is the most prevalent genetic form and caused by mutations in the phosphate-regulating endopeptidase (PHEX) gene. XLH is associated with growth retardation and bone deformities. This rare variety was diagnosed in a 2 year 4 month old child who had brought by parents with complaint of abnormal gait. In the present case, clinical and radiographic aspects of manifestation of familial hypophosphatemic rickets are discussed.