Atypical Fanconi syndrome-neonatal hyperinsulinism syndrome

A rare genetic disease characterized by the association of Fanconi syndrome and nephrocalcinosis in addition to neonatal hyperinsulinism and macrosomia. Patients display a phenotype of proximal tubulopathy characterized by generalized aminoaciduria, low molecular weight proteinuria, glycosuria, hyperphosphaturia and hypouricemia, and additional features not normally seen in Fanconi syndrome (apart from nephrocalcinosis), namely renal impairment, hypercalciuria with relative hypocalcemia, and hypermagnesemia.