PDF(Pubmed)
Abstract：
Vitamin D hydroxylation-deficient rickets type 1A is an autosomal recessive disorder caused by pathogenic variants in CYP27B1 gene, which encodes for 1α-hydroxylase, the enzyme responsible for the conversion of 25-OH vitamin D into its active form 1,25(OH)2 vitamin D. We report the case of a 3-year-old female Mexican patient with growth retardation and progressive bone deformity, whose laboratory studies showed 25-OH vitamin D deficiency, a normal serum calcium and an elevated intact parathyroid hormone level that remained high despite calcitriol, cholecalciferol, and calcium supplementation. 99mTc sestamibi gammagram showed findings suggestive of parathyroid hyperplasia. Bone histomorphometry showed an image consistent with hyperparathyroidism without findings of osteomalacia, so normocalcemic primary hyperparathyroidism was suspected and a subtotal parathyroidectomy was performed, with the patient developing postoperative hypoparathyroidism. When she arrived at our clinic at age 18 years, she showed calcium- and calcitriol-dependent hypocalcemia, with secondary hyperparathyroidism and low levels of 1,25(OH)2 vitamin D in the absence of a 25-OH vitamin D deficiency, reflecting a defect in 1α-hydroxylation. Molecular testing revealed compound heterozygous variants in CYP27B1 gene. This is the first reported case of an inherited disorder of vitamin D metabolism that was diagnosed and surgically treated as primary hyperparathyroidism.
摘要：
维生素D羟化缺乏症1A型是一种由CYP27B1基因致病变异引起的常染色体隐性遗传疾病，编码1α-羟化酶，负责将25-OH维生素D转化为其活性形式1,25（OH）2维生素D的酶。我们报告了一名3岁的墨西哥女性患者，患有生长迟缓和进行性骨畸形，他们的实验室研究显示25-OH维生素D缺乏，正常的血清钙和完整的甲状旁腺激素水平升高，尽管骨化三醇，胆钙化醇,和补钙。99mTcsestamibigammagram显示提示甲状旁腺增生的发现。骨组织形态计量学显示图像与甲状旁腺功能亢进一致，没有骨软化的发现，因此怀疑血钙正常的原发性甲状旁腺功能亢进，并进行了甲状旁腺次全切除术，患者发生术后甲状旁腺功能减退。当她18岁来到我们的诊所时，她表现为钙和骨化三醇依赖性低钙血症,在没有25-OH维生素D缺乏的情况下，继发性甲状旁腺功能亢进和低水平的1,25（OH）2维生素D，反映了1α-羟基化的缺陷。分子测试显示CYP27B1基因中的复合杂合变体。这是第一例报道的遗传性维生素D代谢疾病，经诊断和手术治疗为原发性甲状旁腺功能亢进。
