Pseudovitamin D-deficiency rickets (PDDR) is a rare autosomal recessive disorder resulting from a defect in renal 25-hydroxyvitamin D 1α-hydroxylase, which is encoded by the CYP27B1 gene. To our best knowledge, 48 mutations of the CYP27B1 gene have been identified so far. In the present study, we investigated CYP27B1 mutations in seven individuals from six separate families and identified nine different mutations: two novel missense mutations (G194R, R259L), three novel and one reported deletion mutations (c1446delA, c1504delA, c311-321del and c. 48-60del), two novel nonsense mutations (c.85G>T, c.580G>T) and 1 reported insertion mutation (c1325-1332insCCCACCC). Our findings enriched the database of CYP27B1 mutations. To investigate the response to short-term treatment with calcitriol in PDDR patients, we additionally collected clinical data of eight PDDR patients from our previous study and analyzed the changes of clinical manifestations and biochemical parameters after treated with calcitriol in the whole 15 patients. The statistical analysis revealed that serum ALP and PTH significantly decreased after 6-month treatment with calcitriol. The height change of the patients is positively related to the duration of the treatment (r=0.772, P=0.009), which implicated the importance of long-term calcitriol supplementation for the growth development of children with PDDR.
14 May 2016 - 17 May 2016