Department of Paediatric Endocrinology and Diabetes, University of Child Health Sciences, The Children's Hospital, Lahore, Pakistan.
Paediatric Endocrinology, Hameed Lateef Hospital, Lahore, Pakistan.
J Pediatr Endocrinol Metab. 2022 Dec 19;36(2):152-157. doi: 10.1515/jpem-2022-0550. Print 2023 Feb 23.
Vitamin D dependent rickets type 1A (VDDR1A) is a rare autosomal recessive condition due to inactivating mutation of . It mimics clinically, biochemically and rediologically to nutritional and hypophosphatemic rickets. In developing countries like Pakistan, VDDR1A is often misdiagnosed as nutritional rickets or hypophosphatemic rickets due lack of free access to 1,25 (OH) 2 D level and genetic testing. This study was aimed to determine the clinical spectrum and diagnostic challenges of VDDR1A due to CYP27B1 mutation in developing countries.
Retrospective review of all cases of VDDR1A due to mutation over a period of two years presenting in the Pediatric Endocrine clinic of Hameed Latif Hospital, Lahore, Pakistan.
Six cases of VDDR1A (4 males) were identified. Mean age of clinical manifestation was 14 (9-24) months. Mean age of presentation to endocrine department was 5.5 (1.5-11.8) years. Growth failure and bony deformities were the most common presentation (n=6), followed by repeated diarrheas and abdominal distension (n=3) and recurrent fractures (n=1). All cases shared same biochemical profile of low/normal calcium, hypophosphatemia, raised alkaline phosphatase, raised PTH, normal/high 25(OH)D and tubular reabsorption of phosphate (TRP) <85%. Patients treated with calcitriol showed rapid healing as compared to those treated with 1-alfacalcidol.
We should have a high index of suspicion of VDDR1A in rickets not responding to cholecalciferol therapy.
维生素 D 依赖性佝偻病 1A 型（VDDR1A）是一种罕见的常染色体隐性遗传疾病，由 基因失活突变引起。它在临床上、生化上和影像学上与营养性佝偻病和低磷血症性佝偻病相似。在像巴基斯坦这样的发展中国家，由于无法自由获得 1,25（OH）2D 水平和基因检测，VDDR1A 经常被误诊为营养性佝偻病或低磷血症性佝偻病。本研究旨在确定由于 CYP27B1 突变导致的 VDDR1A 在发展中国家的临床谱和诊断挑战。
回顾性分析了在巴基斯坦拉合尔 Hameed Latif 医院儿科内分泌科就诊的 2 年内患有 CYP27B1 突变导致的 VDDR1A 的所有病例。
共发现 6 例 VDDR1A（4 名男性）。临床表现的平均年龄为 14 个月（9-24 个月）。到内分泌科就诊的平均年龄为 5.5 岁（1.5-11.8 岁）。生长发育迟缓和骨骼畸形是最常见的表现（n=6），其次是反复腹泻和腹胀（n=3）和反复骨折（n=1）。所有病例均具有相同的生化特征，即低/正常钙、低磷血症、碱性磷酸酶升高、甲状旁腺激素升高、25（OH）D 正常/升高和磷重吸收（TRP）<85%。与用 1-阿尔法骨化醇治疗的患者相比，用骨化三醇治疗的患者恢复更快。
对于对胆钙化醇治疗无反应的佝偻病，我们应该高度怀疑 VDDR1A。
