SHM Converge Scientific Abstract ePoster Gallery-Diabetes and a Solitary Kidney: A Unifying Diagnosis

Pdf Summary

This case describes a 44-year-old man with presumed type 2 diabetes, gastroparesis, cognitive impairment, chronic hypomagnesemia, and an incidental solitary cystic kidney. Because the combination of diabetes plus renal malformation suggested an underlying genetic syndrome, he underwent genetic testing, which revealed a heterozygous HNF1B deletion consistent with Maturity-Onset Diabetes of the Young type 5 (MODY5).<br /><br />MODY5 is one of several inherited MODY syndromes caused by mutations or deletions in the HNF1B gene, a transcription factor important in embryonic development. It is usually inherited in an autosomal dominant pattern with incomplete penetrance. Although MODY syndromes account for about 1% of diabetes cases, they are frequently misdiagnosed; MODY5 makes up roughly 5–6% of MODY diagnoses.<br /><br />Key clinical features of MODY5 include early-onset diabetes, pancreatic atrophy, renal developmental abnormalities, and progressive renal insufficiency. Other associated findings may include hypomagnesemia, elevated liver enzymes, genitourinary abnormalities, and cognitive impairment. Because the phenotype is variable, diagnosis often requires genetic panel testing.<br /><br />Correct diagnosis matters because it affects management. In MODY5, insulin is typically needed due to impaired beta-cell function and reduced insulin secretion, while oral agents such as sulfonylureas, meglitinides, and metformin are less effective. Close monitoring of kidney function is essential because renal disease can progress. Magnesium supplementation may be required for chronic hypomagnesemia, and nephrology referral may be needed.<br /><br />Overall, MODY5 should be suspected in patients with diabetes and abnormal renal development, especially when accompanied by genitourinary anomalies, liver abnormalities, cognitive impairment, or hypomagnesemia. Accurate diagnosis helps optimize diabetes treatment, reduce recurrent hospitalizations, monitor renal decline, and support genetic counseling and family planning.

Asset Subtitle

Esther Y. Hsiang

Meta Tag

Author List Esther Y. Hsiang, Robert J. Weber

Category Clinical Vignettes

Concept Maturity-Onset Diabetes of the Young type 5

Concept Diabetes Mellitus

Concept Renal Malformation

Concept Genetic Testing

Concept Hypomagnesemia

Distinguished Non-Finalist

Presenter Organization UCSF Division of Hospital Medicine

Presenting Author Esther Y. Hsiang

Track Adult

Keywords

MODY5

HNF1B deletion

diabetes

renal malformation

hypomagnesemia

cognitive impairment

cystic kidney

genetic testing

autosomal dominant

kidney disease

Maturity-Onset Diabetes of the Young type 5

Diabetes Mellitus

Renal Malformation

Genetic Testing

Hypomagnesemia