Introduction:

Molecular diagnosis of monogenic diabetes mellitus is important for individualized patient

care. Next‑generation sequencing (NGS) enables a simultaneous analysis of multiple genes in a single test.

Objectives:

We aimed to assess the feasibility of using NGS for detecting mutations in a set of known

monogenic diabetes gene mutations in a cohort of Polish patients with maturity‑onset diabetes of the

young (MODY) with earlier negative Sanger sequencing results for HNF1A‑MODY or GCK‑MODY.

Patient s and methods

We selected a panel of 28 chromosomal genes in which mutations have been

reported to cause monogenic diabetes. The MiSeq platform was used for NGS. An exon‑capture assay

was designed to include coding regions and splice sites. A total of 54 patients with existing negative

Sanger sequencing screening results for HNF1A or GCK gene mutations were selected for the study.

Results:

NGS results were generated for all 54 patients and 9 positive controls with previously identified

HNF1A or GCK gene mutation. All selected positive controls were confirmed by NGS. Among 28

genes, mutations were detected in 16. The type of the analyzed genetic changes was described in the

NGS study as high (n = 3) or moderate (n = 76). Among the detected mutations, there were 4 known

GCK gene mutations that had been previously missed in Sanger sequencing. So far, Sanger sequencing

allowed us to confirm 21 gene mutations detected by NGS, and segregation with diabetes in 14 pedigrees.

Conclusions:

Our pilot study using NGS for monogenic diabetes screening in the MODY cohort confirmed

that it improves the detection of diabetes‑related sequence differences. The screening with NGS

should also include diabetic patients for whom Sanger‑based screening for particular subtypes of MODY

provided negative results.