Variants of the HNF4A and HNF1A genes in patients with impaired glucose metabolism and dyslipidemia

Abstract

Maturity onset diabetes of the young is a dominantly inherited form of monogenic diabetes, diagnosed mainly before the age of 35 years. Mutations in the HNF1A and HNF4A genes are associated with diabetes mellitus of the HNF1A-MODY and HNF4A-MODY subtypes, respectively. These two forms of MODY are characterized by dyslipidemia in addition to impaired glucose metabolism due to the altered function HNF1A and HNF4A proteins. The aim of this study was a genetic analysis of young patients with the MODY phenotype and dyslipidemia with a burdened family history. Material and methods. The probands underwent targeted DNA sequencing using the Illumina MiSeq NGS System. The target panel included the coding regions and splicing sites of MODY-associated genes: HNF4A, GCK, HNF1A, PDX1, HNF1B, NEUROD1, KLF11, CEL, PAX4, INS, BLK, KCNJ11, ABCC8, and APPL1. Results. A heterozygous single nucleotide deletion NM_000457.4: c.153del (3’rule) was found in proband P1 in the HNF4A gene. In proband P2, single nucleotide deletion NM_000545.8: c.335del (3 ‘rule) in the HNF1A gene was detected in a heterozygous state. Both variants are located in the coding parts of the genes, led to a shift in the reading frame and have not been described in the literature and databases earlier. Conclusions. Taking into account the phenotypic features of probands, we assume that the variants NM_000545.8: c.335del (rule 3) in the HNF1A gene and NM_000457.4: c.153del (rule 3) of the HNF4A gene are associated with different MODY subtypes in these individuals. After verification of MODY-HNF1A and MODY-HNF4A diagnosis, it is necessary to monitor the lipid profile parameters (total cholesterol, low and high density lipoprotein cholesterol, triglycerides) and prescribe appropriate drug therapy.