Shivnitwar Sachin, Raut Sandesh S, Kanitkar Shubhangi, Bagare Prasad Chandrakant
Dr. D. Y. Patil Medical College, Hospital and Research Centre, Pune, Maharashtra, India.
Ann Afr Med. 2025 Jun 2. doi: 10.4103/aam.aam_86_25.
Gitelman syndrome (GS) is a rare autosomal recessive salt-losing tubulopathy characterized by hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria. While typically presenting in adolescence or early adulthood, atypical presentations and delayed diagnoses into later adulthood pose significant clinical challenges. We report a case of a 60-year-old female who presented with generalized weakness, lethargy, and severe electrolyte abnormalities, including profound hyponatremia (109 mmol/L), hypokalemia (2.91 mmol/L), hypocalcemia (<6.0 mg/dL), and hypomagnesemia (0.6 mg/dL). Laboratory investigations revealed metabolic alkalosis, hypochloremia, elevated parathyroid hormone (172.90 pg/ml), and inappropriate renal potassium wasting. Urinary studies showed relative hypocalciuria in the context of severe hypocalcemia. Genetic testing revealed no pathogenic variants in the SLC12A3 gene typically associated with GS, though variants of uncertain significance were identified in SLC22A12 and VPS33B genes. Management included aggressive electrolyte replacement, spironolactone, and dietary modifications, resulting in clinical improvement despite incomplete normalization of electrolytes. This case illustrates the complex clinical spectrum of GS, highlighting the importance of considering this diagnosis in older adults with unexplained electrolyte abnormalities. The absence of confirmatory SLC12A3 mutations despite classic biochemical features supports emerging evidence of genetic heterogeneity in GS. This case emphasizes the value of clinical diagnosis when genetic confirmation is lacking and the effectiveness of targeted symptomatic management. GS should be considered in the differential diagnosis of electrolyte abnormalities across all age groups. A high index of clinical suspicion and characteristic biochemical profile can guide diagnosis and management even in the absence of confirmatory genetic findings.
吉特曼综合征（GS）是一种罕见的常染色体隐性遗传性失盐性肾小管病，其特征为低钾性代谢性碱中毒、低镁血症和低钙尿症。虽然该病通常在青春期或成年早期出现，但非典型表现以及诊断延迟至成年后期会带来重大的临床挑战。我们报告一例60岁女性病例，该患者表现为全身无力、嗜睡和严重的电解质异常，包括严重低钠血症（109 mmol/L）、低钾血症（2.91 mmol/L）、低钙血症（<6.0 mg/dL）和低镁血症（0.6 mg/dL）。实验室检查显示代谢性碱中毒、低氯血症、甲状旁腺激素升高（172.90 pg/ml）以及不适当的肾性钾丢失。尿液检查显示在严重低钙血症的情况下存在相对低钙尿症。基因检测未发现通常与GS相关的SLC12A3基因的致病变异，不过在SLC22A12和VPS33B基因中发现了意义未明的变异。治疗包括积极的电解质补充、螺内酯和饮食调整，尽管电解质未完全恢复正常，但临床症状有所改善。该病例说明了GS复杂的临床谱，强调了在患有不明原因电解质异常的老年人中考虑这一诊断的重要性。尽管具有典型的生化特征，但缺乏确诊的SLC12A3突变支持了GS中基因异质性的新证据。该病例强调了在缺乏基因确诊时临床诊断的价值以及针对性对症治疗的有效性。在所有年龄组的电解质异常鉴别诊断中都应考虑GS。即使在没有确诊基因结果的情况下，高度的临床怀疑和特征性的生化特征也可指导诊断和治疗。
