RENAL CYSTS AND DIABETES (RCAD)
ANALYSIS OF THE HNF1B GENE IN RENAL CYSTS AND DIABETES (RCAD)
The Renal Cysts And Diabetes (RCAD) syndrome is caused by heterozygous mutations in the HNF1B gene (Bingham et al. 2000 Kidney Int 57:898-907; Edghill et al. 2006 J Med Genet 43:84-90). Whole gene deletions account for up to 50% of mutations, and 40% of HNF1B mutations are de novo. An absence of family history of renal disease or diabetes should therefore not exclude genetic testing for RCAD.
Clinical presentations of RCAD usually include at least two of the following:
- Unexplained renal cystic disease (renal cysts may be detected in utero)
- Renal dysplasia
- Renal hypoplasia/agenesis
- Early onset non-insulin dependent diabetes
- Reproductive tract malformations
- Hyperuricaemia and early onset gout
- Deranged liver functionFurther information is available at diabetesgenes and rarerenal about RCAD and HNF1B mutations
- The severity of the renal phenotype is variable, from enlarged cystic kidneys incompatible with life to normal renal development and function, and HNF1B mutations are a rare cause of diabetes in the absence of known renal disease (Edghill et al. 2013 Diabet Med 30:114-117).