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.

Gitelman综合征（GS）是一种罕见的常染色体隐性盐丢失性肾小管病，特征为低钾血症代谢性碱中毒、低镁血症和低钙尿。尽管通常在青春期或成年早期出现症状，但不典型的临床表现和延迟至晚年才做出诊断的情况对临床治疗构成了重大挑战。我们报告了一例60岁女性患者病例，她表现为全身乏力、倦怠以及严重的电解质异常，包括重度低钠血症（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，以及甲状旁腺激素升高（172.90 pg/ml），并伴有不适当的肾钾丢失。尿液分析表明，在严重低钙血症的情况下存在相对的低钙尿症。基因检测未发现与GS相关的SLC12A3基因中的致病变异，尽管在SLC22A12和VPS33B基因中发现了意义不确定的变异。治疗包括积极的电解质替代、使用螺内酯以及饮食调整，结果临床症状得到改善，虽然电解质未完全恢复正常。此病例展示了Gitelman综合征复杂的临床谱系，并强调了对老年人不明原因电解质异常患者应考虑该诊断的重要性。尽管存在经典的生化特征但缺乏SLC12A3确认的变异支持该病遗传异质性的新兴证据。该案例突出了在缺乏基因确证时临床诊断的价值以及针对性症状管理的有效性。Gitelman综合征应在所有年龄段患者的电解质异常鉴别诊断中予以考虑。具有高度临床警觉性和特征生化谱图可指导诊断和治疗，即使没有确认的基因发现。

关键词： 电解质紊乱；Gitelman 综合征；SLC12A3；代谢性碱中毒；低钾血症；低镁血症；低钠血症；肾小管病。