Abstract
The renal cysts and diabetes syndrome (RCAD), also known as HNF1B-MODYor MODY5, is caused by the deletion or point mutation of HNF1B gene which leads to the depletion of HNF1B transcription factor. The main clinical components of RCAD include cystic kidney disease or other developmental anomalies of the kidneys and diabetes mellitus which typically manifests in the second decade of life or later.
Renal disorders may lead to the development of chronic renal insufficiency already in childhood or young adulthood. The other symptoms include hepatic impairment - cholestatic jaundice in middle-aged patients, sometimes even neonatal cholestasis, atrophy of the pancreas with the impairment of exocrine pancreatic secretion and some congenital anomalies of the genital tract.
As opposed to the other forms of MODY diabetes, the family history may not be positive because most of the deviations of HNF1B appear de novo. We associate RCAD in particular with adults suffering from diabetes and cystic kidney disease and/or cholestatic jaundice and children with cystic kidney disease of unclear etiology, even without the presence of diabetes.
A supportive finding may be hypomagnesemia which occurs in up to 70 % of patients diagnosed with HNF1B related disease and hyperuricemia.