Singhania Pankaj, Dhar Abhranil, Deshpande Aditya, Das Debaditya, Agrawal Neeti, Chakraborty Partha Pratim, Bhattacharjee Rana, Roy Ajitesh
Department of Endocrinology and Metabolism, Institute of Postgraduate Medical Education and Research, Kolkata, West Bengal, India.
Department of Endocrinology, Medical College Kolkata, Kolkata, India.
J Pediatr Endocrinol Metab. 2023 Jul 13;36(9):879-885. doi: 10.1515/jpem-2023-0155. Print 2023 Sep 26.
Proximal renal tubular acidosis (pRTA) is characterized by a defect in the ability of the proximal convoluted tubule to reabsorb bicarbonate. The biochemical hallmark of pRTA is hyperchloremic metabolic acidosis with a normal anion gap, accompanied by appropriate acidification of the urine (simultaneous urine pH <5.3). Isolated defects in bicarbonate transport are rare, and pRTA is more often associated with Fanconi syndrome (FS), which is characterized by urinary loss of phosphate, uric acid, glucose, amino acids, low-molecular-weight proteins, and bicarbonate. Children with pRTA may present with rickets, but pRTA is often overlooked as an underlying cause of this condition.
We report six children with rickets and short stature due to pRTA. One case was idiopathic, while the remaining five had a specific underlying condition: Fanconi-Bickel syndrome, Dent's disease, nephropathic cystinosis, type 1 tyrosinemia, and sodium-bicarbonate cotransporter 1-A (NBC1-A) defect.
Five of these six children had features of FS, while the one with NBC1-A defect had isolated pRTA.
近端肾小管酸中毒（pRTA）的特征是近端曲管重吸收碳酸氢盐的能力存在缺陷。pRTA的生化标志是高氯性代谢性酸中毒伴正常阴离子间隙，并伴有尿液的适当酸化（同时尿液pH<5.3）。孤立的碳酸氢盐转运缺陷很少见，pRTA更常与范科尼综合征（FS）相关，其特征是磷酸盐、尿酸、葡萄糖、氨基酸、低分子量蛋白质和碳酸氢盐的尿丢失。患有pRTA的儿童可能会出现佝偻病，但pRTA常被忽视是这种情况的潜在原因。
我们报告了6例因pRTA导致佝偻病和身材矮小的儿童。1例为特发性，其余5例有特定的潜在疾病：范科尼-比克尔综合征、丹特病、肾病性胱氨酸病、1型酪氨酸血症和碳酸氢钠协同转运蛋白1-A（NBC1-A）缺陷。
这6名儿童中有5名具有FS的特征，而1名患有NBC1-A缺陷的儿童患有孤立性pRTA。
