[Vitamin D1alpha-hydroxylase deficiency as the cause of severe rickets in a 1-year-old-old boy].
We describe a 15-month-old boy referred to the hospital because of delayed development of motor skills and growth retardation. Blood samples and X-rays of the wrists and knees revealed rickets. He was treated with oral calcium and vitamin D with modest clinical and biochemical effect. 1,25-dihydroxyvitamin D was undetectable in laboratory tests. Vitamin D1alpha-hydroxylase deficiency was suspected and confirmed by DNA analysis, which revealed a 7 bp duplication in exon 8 of the CYP27B1 gene. The treatment was changed to an activated formula of vitamin D, alphacalcidol, whereupon the clinical and biochemical symptoms rapidly improved.
Odense Universitetshospital, Børneafdelingen. sbeck-nielsen@health.sdu.dk
Signe Sparre
SS
Beck-Nielsen
Niels Thomas
NT
Hertel
Bendt
B
Brock-Jacobsen
D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000172:deficiency* / Q000235:genetics; D002118:Calcium / Q000008:administration & dosage; D006130:Growth Disorders / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000201:enzymology / Q000209:etiology; D006225:Hand / Q000000981:diagnostic imaging; D006801:Humans; D006887:Hydroxycholecalciferols / Q000008:administration & dosage; D007223:Infant; D008297:Male; D009048:Motor Skills; D011859:Radiography; D012279:Rickets / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000201:enzymology* / Q000209:etiology; D013250:Steroid Hydroxylases / Q000172:deficiency*
D006887:Hydroxycholecalciferols; D013250:Steroid Hydroxylases; C406322:vitamin D 1-alpha hydroxylase; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase; D002118:Calcium; C008088:alfacalcidol