Work

A Case of Hyperinsulinemic Hypoglycaemia Associated with Atypical Fanconi Renal Tubulopathy Syndrome Caused by an HNF4A Variant

Year: 2025

Type: article

Abstract: Introduction: This case illustrates the challenges in the diagnosis of a rare disease with an intricate orientation. The definitive genetic diagnosis was carried out after establishing crucial correlations between the preliminary clinical indications and the laboratory findings. Case Presentation: The initial presentation was myoclonic jerks. This was a direct consequence of hyperinsulinaemic hypoglycaemia (HH), and not a phenotypic characteristic described in previous case reports. Linking this to glycaemia led to the evaluation of response to fasting, where inadequate insulin suppression resulted in hypoketotic hypoglycaemia. The diagnosis of chronic kidney dysfunction associated with atypical Fanconi renal tubulopathy syndrome type 4 (FRTS4) was indicated on the basis of a decreased estimated glomerular filtration rate, nephrocalcinosis, millimetric lithiasis, rickets, and complex proximal tubulopathy. This indicated atypical FRTS4 as associated with HH and necessitated further molecular genetic testing. Conclusion: gene variants associated with atypical FRTS and HH is limited. It is therefore important to report such cases to contribute to the growing body of evidence and help identify pathogenic HNF4A variants and their implications.

Source: Case Reports in Nephrology and Dialysis

DOI: 10.1159/000549545