Pathogenic variant in HNF1B – Implications for genetic testing and counseling

Pathogenic variants in HNF1B cause an autosomal dominant syndrome sometimes referred to as renal cysts and diabetes syndrome, although not all affected individuals have kidney cysts and diabetes, and some have other manifestations. We prefer the term "HNF1B syndrome." Up to 50% of pathogenic variants in HNF1B occur de novo. Identifying a familial variant and distinguishing a de novo from an inherited variant in the tested individual allows individuals without the variant to avoid extensive evaluations and monitoring. Monitoring for individuals who carry the familial variant is listed in the inset box. Involvement of a genetics expert or an expert in HNF1B syndromes is advised. Refer to UpToDate for additional details of evaluation, monitoring, and interventions.