BACKGROUND: HNF1A-MODY (MODY3) is a common subtype of autosomal dominant diabetes. Unlike HNF4-MODY where fetal macrosomia and early postnatal hyperinsulinemic hypoglycemia have been reported, history of transient insulin overproduction has not yet been recognized in individuals with HNF1A-MODY. CASE REPORT: Here, we report on a 40-year-old male patient with HNF1A mutation p.Arg272His (c.815G>A) having a history of fetal macrosomia (4750 g, 59 cm), and, at least, one attack of symptomatic hypoglycemia in childhood. Diabetes was subsequently diagnosed at 19 years of age. The proband's daughter who developed diabetes at 16 years carries the same mutation, but her birth weight and length were in the upper normal range, and she never experienced hypoglycemic symptoms. CONCLUSION: The observation of fetal macrosomia and hypoglycemia in childhood is indicative of a biphasic impact of the HNF1A mutation on p-cell function over the lifespan, leading from inappropriate insulin oversecretion to final clinical diabetes.

Department of Pediatrics University Hospital Motol and 2nd Faculty of Medicine Charles University Prague Prague Czech Republic

References provided by Crossref.org

Neonatal hypoglycaemia in the offsprings of parents with maturity-onset diabetes of the young (MODY)

Identification of MODY among patients screened for gestational diabetes: a clinician's guide