Feinstein Yael, Yerushalmi Baruch, Loewenthal Neta, Alkrinawi Soliman, Birk Ohad S, Parvari Ruti, Hershkovitz Eli
Pediatric Endocrinology Unit, Soroka Medical Center, Faculty of Health Sciences, Beer Sheva, Israel.
Horm Res Paediatr. 2014;81(5):336-42. doi: 10.1159/000358327. Epub 2014 Apr 4.
We identified patients of Bedouin origin with a mutation in carbonic anhydrase XII (CA XII) leading to hyponatremia due to excessive salt loss via sweat.
The medical records of patients were reviewed for clinical and laboratory data.
A total of 11 subjects were identified; 7 symptomatic patients presented with hyponatremic dehydration in infancy. Screening of the entire kindred identified 4 asymptomatic individuals with elevated sweat chloride. All symptomatic patients had failure to thrive and moderate-severe hyponatremia (106-124 mmol·l(-1)); 6 had hypochloremia (79-94 mmol·l(-1)). All asymptomatic subjects had normal or near-normal serum sodium and chloride concentrations. Both symptomatic and asymptomatic subjects had normal renal functions and normal cortisol response on low-dose ACTH test. All symptomatic patients were treated by dietary salt, which prevents episodes of hyponatremic dehydration and promotes growth. At follow-up, the chief complaints remained heat intolerance, accumulation of salt precipitates on the face and hyperhidrosis. No evidence for chronic renal, respiratory, gastrointestinal or fertility abnormalities was found.
Recognizing this newly described entity and differentiating it from cystic fibrosis and pseudohypoaldosteronism are important. Patients with CA XII mutations should be followed even after early childhood, especially in hot temperatures and intense physical activity.
我们确定了一些贝都因族裔的患者，他们的碳酸酐酶XII（CA XII）发生突变，导致因汗液中盐分过度流失而出现低钠血症。
回顾患者的病历以获取临床和实验室数据。
共确定了11名受试者；7名有症状的患者在婴儿期出现低钠血症性脱水。对整个家族进行筛查发现4名无症状个体汗液氯化物升高。所有有症状的患者均生长发育迟缓且有中度至重度低钠血症（106 - 124 mmol·l⁻¹）；6名患者有低氯血症（79 - 94 mmol·l⁻¹）。所有无症状受试者的血清钠和氯化物浓度正常或接近正常。有症状和无症状的受试者肾功能均正常，低剂量促肾上腺皮质激素试验时皮质醇反应正常。所有有症状的患者均接受饮食补盐治疗，这可预防低钠血症性脱水发作并促进生长。随访时，主要症状仍为不耐热、面部盐沉淀积聚和多汗。未发现慢性肾脏、呼吸、胃肠道或生育异常的证据。
认识到这个新描述的疾病实体并将其与囊性纤维化和假性醛固酮减少症区分开来很重要。即使在儿童早期之后，CA XII突变患者也应接受随访，尤其是在炎热天气和剧烈体力活动时。
