Posters
Presenting Author Academic/Professional Position
Catherin Matos Munoz
Academic Level (Author 1)
Resident
Discipline/Specialty (Author 1)
Internal Medicine
Academic Level (Author 2)
Resident
Discipline/Specialty (Author 2)
Internal Medicine
Academic Level (Author 3)
Resident
Discipline/Specialty (Author 3)
Internal Medicine
Academic Level (Author 4)
Resident
Discipline/Specialty (Author 4)
Internal Medicine
Academic Level (Author 5)
Faculty
Discipline/Specialty (Author 5)
Internal Medicine
Discipline Track
Clinical Science
Abstract Type
Research/Clinical
Abstract
Introduction: Magnesium constitutes an essential electrolyte integral to the functioning of neuromuscular systems, the regulation of cardiovascular parameters, and the facilitation of metabolic processes. Chronic hypomagnesemia may precipitate significant complications, including the onset of arrhythmias and seizures. In cases where hypomagnesemia is refractory to supplementation and manifests in multiple family members, a hereditary tubulopathy, such as Gitelman syndrome (GS), warrants consideration. Gitelman syndrome is classified as an autosomal recessive disorder, resulting from mutations in the SLC12A3 gene, which impairs the thiazide-sensitive sodium-chloride cotransporter located in the distal convoluted tubule.
Case Presentation: A 39-year-old female with a history of classical Hodgkin lymphoma, which was managed with ABVD chemotherapy in 2023 and is presently in a state of remission, presented with a case of persistent hypomagnesemia. Serum magnesium levels persistently remained below 1.0 mg/dL despite the administration of both oral and intravenous magnesium supplementation. Importantly, hypomagnesemia was noted prior to the initiation of chemotherapy, thereby ruling it out as the singular contributing factor. Additionally, her sibling also experienced chronic hypomagnesemia necessitating intravenous therapy, and both individuals received diagnoses of type 2 diabetes mellitus in early adulthood.
In light of the familial predisposition, the early onset of diabetes, and the chronic electrolyte imbalances, a genetic assessment was undertaken. The differential diagnosis encompassed Gitelman syndrome as well as disorders associated with HNF1B. Genetic analysis substantiated the presence of biallelic mutations in the SLC12A3 gene, corroborating a diagnosis of Gitelman syndrome. The patient demonstrated clinical manifestations characteristic of Gitelman syndrome; however, she did not exhibit hypocalciuria, which is typically associated with this condition. Furthermore, her parathyroid hormone and vitamin D levels remained within normal limits, effectively excluding potential confounding endocrine disorders.
Discussion: Gitelman syndrome is distinguished by the presence of hypokalemia, hypomagnesemia, metabolic alkalosis, and typically hypocalciuria. Nonetheless, normocalciuria is observed in as many as 8% of cases that have been genetically validated. The clinical heterogeneity exhibited in Gitelman syndrome may be modulated by genetic modifiers, the hormonal environment, or concurrent metabolic disorders. In Gitelman syndrome, the impaired sodium-chloride cotransport induces a secondary stimulation of the renin-angiotensin-aldosterone system, which enhances sodium reabsorption in the distal tubule via epithelial sodium channels (ENaC) and facilitates the loss of potassium and hydrogen ions. The mechanisms responsible for magnesium wasting are not thoroughly elucidated but may involve dysfunction of the transient receptor potential melastatin 6 (TRPM6) channel or structural alterations in the distal renal tubule.
The persistent hypomagnesemia observed in this patient, coupled with early-onset diabetes and a positive family history, supports the notion of a genetic basis rather than an acquired etiology. Although her clinical presentation did not exhibit all of the classic biochemical markers of Gitelman syndrome, particularly hypocalciuria, her genetic confirmation emphasizes the necessity of recognizing atypical clinical manifestations. The therapeutic approach remains supportive, entailing continuous electrolyte replacement and vigilant monitoring for potential complications such as arrhythmias.
Conclusion: This case highlights the diagnostic importance of considering hereditary tubulopathies in patients with unexplained, refractory hypomagnesemia, especially with a positive family history and early-onset metabolic disturbances. Genetic testing for SLC12A3 mutations is essential for definitive diagnosis, even in the absence of classic biochemical features such as hypocalciuria. Identifying a genetic cause enables tailored long-term management and informs screening for at-risk family members.
Presentation Type
Poster
Recommended Citation
Calderon, Aura M. C.; Mogollon, Ivan; Matos, Catherine; Loayza, Jose; and Cobos, Everardo, "Case Report: Familial Hypomagnesemia in a Patient with History of Hodgkin Lymphoma" (2025). Research Colloquium. 16.
https://scholarworks.utrgv.edu/colloquium/2025/posters/16
Included in
Case Report: Familial Hypomagnesemia in a Patient with History of Hodgkin Lymphoma
Introduction: Magnesium constitutes an essential electrolyte integral to the functioning of neuromuscular systems, the regulation of cardiovascular parameters, and the facilitation of metabolic processes. Chronic hypomagnesemia may precipitate significant complications, including the onset of arrhythmias and seizures. In cases where hypomagnesemia is refractory to supplementation and manifests in multiple family members, a hereditary tubulopathy, such as Gitelman syndrome (GS), warrants consideration. Gitelman syndrome is classified as an autosomal recessive disorder, resulting from mutations in the SLC12A3 gene, which impairs the thiazide-sensitive sodium-chloride cotransporter located in the distal convoluted tubule.
Case Presentation: A 39-year-old female with a history of classical Hodgkin lymphoma, which was managed with ABVD chemotherapy in 2023 and is presently in a state of remission, presented with a case of persistent hypomagnesemia. Serum magnesium levels persistently remained below 1.0 mg/dL despite the administration of both oral and intravenous magnesium supplementation. Importantly, hypomagnesemia was noted prior to the initiation of chemotherapy, thereby ruling it out as the singular contributing factor. Additionally, her sibling also experienced chronic hypomagnesemia necessitating intravenous therapy, and both individuals received diagnoses of type 2 diabetes mellitus in early adulthood.
In light of the familial predisposition, the early onset of diabetes, and the chronic electrolyte imbalances, a genetic assessment was undertaken. The differential diagnosis encompassed Gitelman syndrome as well as disorders associated with HNF1B. Genetic analysis substantiated the presence of biallelic mutations in the SLC12A3 gene, corroborating a diagnosis of Gitelman syndrome. The patient demonstrated clinical manifestations characteristic of Gitelman syndrome; however, she did not exhibit hypocalciuria, which is typically associated with this condition. Furthermore, her parathyroid hormone and vitamin D levels remained within normal limits, effectively excluding potential confounding endocrine disorders.
Discussion: Gitelman syndrome is distinguished by the presence of hypokalemia, hypomagnesemia, metabolic alkalosis, and typically hypocalciuria. Nonetheless, normocalciuria is observed in as many as 8% of cases that have been genetically validated. The clinical heterogeneity exhibited in Gitelman syndrome may be modulated by genetic modifiers, the hormonal environment, or concurrent metabolic disorders. In Gitelman syndrome, the impaired sodium-chloride cotransport induces a secondary stimulation of the renin-angiotensin-aldosterone system, which enhances sodium reabsorption in the distal tubule via epithelial sodium channels (ENaC) and facilitates the loss of potassium and hydrogen ions. The mechanisms responsible for magnesium wasting are not thoroughly elucidated but may involve dysfunction of the transient receptor potential melastatin 6 (TRPM6) channel or structural alterations in the distal renal tubule.
The persistent hypomagnesemia observed in this patient, coupled with early-onset diabetes and a positive family history, supports the notion of a genetic basis rather than an acquired etiology. Although her clinical presentation did not exhibit all of the classic biochemical markers of Gitelman syndrome, particularly hypocalciuria, her genetic confirmation emphasizes the necessity of recognizing atypical clinical manifestations. The therapeutic approach remains supportive, entailing continuous electrolyte replacement and vigilant monitoring for potential complications such as arrhythmias.
Conclusion: This case highlights the diagnostic importance of considering hereditary tubulopathies in patients with unexplained, refractory hypomagnesemia, especially with a positive family history and early-onset metabolic disturbances. Genetic testing for SLC12A3 mutations is essential for definitive diagnosis, even in the absence of classic biochemical features such as hypocalciuria. Identifying a genetic cause enables tailored long-term management and informs screening for at-risk family members.
