Novel HNF1A gene mutation in maturity-onset diabetes of the young: A case report

BACKGROUNDMaturity-onset diabetes of the young 3 (MODY3), caused by mutations in the HNF1A gene, is the most common subtype of MODY. The diagnosis of MODY3 is critical because a low dose of sulfonylurea agents can achieve glucose control. CASE SUMMARYWe describe a patient with MODY3 involving a novel splicing mutation, in whom low-dose gliclazide was sufficient to control clinically significant hyperglycemia. Sanger sequencing identified a splicing HNF1A mutation in 12q24 NM_000545.5 Intron5 c.1108-1G>A. Glycemic control has been maintained without insulin therapy for 28 mo after the diagnosis of diabetes. CONCLUSIONThis case report highlights a novel HNF1A gene mutation in MODY3 that is responsive to sulfonylurea therapy.