RRAGD-associated autosomal dominant kidney hypomagnesemia with cardiomyopathy (ADKH-RRAGD): a review on the clinical manifestations and therapeutic options.

BACKGROUND: A hereditary condition primarily affecting the kidneys and heart has newly been identified: the RRAGD-associated Autosomal Dominant Kidney Hypomagnesemia with Cardiomyopathy (ADKH-RRAGD). This disorder is characterized by renal loss of magnesium and potassium, coupled with varying degrees of cardiac dysfunction. These range from arrhythmias to severe dilated cardiomyopathy, which may require heart transplantation. Mutations associated with RRAGD significantly disrupt the non-canonical branch of the mTORC1 pathway. This disruption hinders the the nuclear translocation and transcriptional activity of the transcription factor EB (TFEB) a crucial regulator of lysosomal and autophagic function. SUMMARY: All identified RRAGD variants compromise kidney function, leading to hypomagnesemia and hypokalemia of various severity. The renal phenotype for most of the variants (i.e. S76L, I221K, P119R, P119L), typically manifests in the second decade of life occasionally preceded by childhood symptoms of dilated cardiomyopathy. In contrast, the P88L variant is associated to dilated cardiomyopathy manifesting in adulthood. To date, the T97P variant has not been linked to cardiac involvement. The most severe manifestations of ADKH-RRAGD, particularly concerning electrolyte imbalance and heart dysfunction requiring transplantation in childhood appear to be associated with the S76L, I221K, P119R variants. KEY MESSAGES: This review aims to provide an overview of the clinical presentation for ADKH-RRAGD, aiming to enhance o awareness, promote early diagnosis and facilitate proper treatment. It also reports on the limited experience in patient management with diuretics, magnesium and potassium supplements, metformin, or calcineurin- and SGLT2-inhibitors.

[Hyponatremia and Electrolyte Disorders in Cancer Patients].

Onconephrology is a rising and rapidly expanding field of medicine in which nephrology and oncology meet each other. Besides multidisciplinary meetings, oncologists and nephrologists often discuss on timing of the treatment, dosage, and side effects management. Cancer patients often encounter different electrolyte disorders. They are mostly secondary to the tumor itself or consequences of its treatment. In the last years, the great efforts to find new therapies like targeted, immune, and cell-based led us to many new side effects. Hyponatremia, hypokalemia, hyperkalemia, hypercalcemia, and hypomagnesemia are among the most common electrolyte disorders. Data have shown a worse prognosis in patients with electrolytic imbalances. Additionally, they cause a delay in chemotherapy or even an interruption. It is important to diagnose promptly these complications and treat them. In this review, we provide a special focus on hyponatremia and its treatment as the most common electrolytes disorder in cancer patients, but also on newly described cases of hypo- and hyperkalemia and metabolic acidosis.