Abou Ziki Maen D, Verjee Mohamud A
Yale Waterbury Internal Medicine Residency Program, Yale University School of Medicine, New Haven, Connecticut, USA.
Department of Medical Education, Weill Cornell Medical College in Qatar, Doha, Qatar.
BMJ Case Rep. 2015 Jan 7;2015:bcr2014206849. doi: 10.1136/bcr-2014-206849.
SLC26A3, a chloride/bicarbonate transporter mainly expressed in the intestines, plays a pivotal role in chloride absorption. We present a 23-year-old woman with a history of congenital chloride diarrhoea (CCD) and renal transplant who was admitted for rehydration and treatment of acute kidney injury after she presented with an acute diarrhoeal episode. Laboratory investigations confirmed metabolic alkalosis and severe hypochloraemia, consistent with her underlying CCD. This contrasts with most other forms of diarrhoea, which are normally associated with metabolic acidosis. Genetic testing was offered and revealed a homozygous non-sense mutation in SLC26A3 (Gly-187-Stop). This loss-of-function mutation results in bicarbonate retention in the blood and chloride loss into the intestinal lumen. Symptomatic management with daily NaCl and KCl oral syrups was supplemented with omeprazole therapy. The loss of her own kidneys is most likely due to crystal-induced nephropathy secondary to chronic volume contraction and chloride depletion. This case summarises the pathophysiology and management of CCD.
SLC26A3是一种主要在肠道表达的氯化物/碳酸氢盐转运体，在氯化物吸收中起关键作用。我们报告一名23岁女性，有先天性氯化物腹泻（CCD）病史且接受了肾移植，在出现急性腹泻发作后因补液及治疗急性肾损伤入院。实验室检查证实存在代谢性碱中毒和严重低氯血症，与她潜在的CCD相符。这与大多数其他形式的腹泻不同，后者通常与代谢性酸中毒相关。进行了基因检测，结果显示SLC26A3存在纯合无义突变（Gly-187-Stop）。这种功能丧失突变导致血液中碳酸氢盐潴留以及氯化物流入肠腔。通过每日口服氯化钠和氯化钾糖浆进行对症治疗，并辅以奥美拉唑治疗。她自身肾脏丧失很可能是由于慢性容量收缩和氯化物耗竭继发的晶体诱导性肾病。本病例总结了CCD的病理生理学及治疗方法。
