Renal cysts and diabetes syndrome

Renal cysts and diabetes syndrome (RCAD), also known as maturity-onset diabetes of the young, type 5 (MODY5), refers to the combination of renal cortical cysts and diabetes mellitus in patients with mutations in the HNF1B gene. When renal cysts are associated with these mutations without disturbances in glucose metabolism, the term HNF1B-associated kidney disease may be used.

Epidemiology

The disorder is the most common known monogenic cause of congenital anomalies of the kidney and urinary tract, accounting for 5-31% depending on the phenotypic selection of the cohort . By contrast, the syndrome accounts for <1% of all maturity-onset diabetes of the young (MODY).

Pathology

Genetics

The disorder, like other forms of maturity-onset diabetes of the young (MODY), is inherited in an autosomal dominant fashion. De novo mutations occur in half of cases. The mutations, whether deletions or coding region/splicing mutations, result in haploinsufficiency of the HNF1B gene (also known as TCF2), which encodes the hepatocyte nuclear factor 1 beta (HNF-1β) transcription factor.

Radiographic features

Ultrasound

The most common finding is bilateral renal cystic dysplasia, including hyperechogenic parenchyma and anechoic cysts . The kidneys are normal to slightly increased in size.

Differential diagnosis

The differential is that of the other pediatric cystic renal diseases.