When do we need to suspect maturity onset diabetes of the young in patients with type 2 diabetes mellitus?

ABSTRACT Objetivo: Maturity onset diabetes of the young (MODY) patients have clinical heterogeneity as shown by many studies. Thus, often it is misdiagnosed to type 1 or type 2 diabetes(T2DM). The aim of this study is to evaluate MODY mutations in adult T2DM patients suspicious in terms of MODY, and to show clinical and laboratory differences between these two situations. Subjects and methods: In this study, we analyzed 72 type 2 diabetic patients and their relatives (35F/37M) who had been suspected for MODY and referred to genetic department for mutation analysis. The gene mutations for MODY have been assessed in the laboratory of Marmara University genetics. Totally 67 (32F/35M; median age 36.1) diabetic patients were analyzed for 7 MODY mutations. Twelve patients who have uncertain mutation (VUS) were excluded from study for further evaluation. MODY(+) (n:30) patients and T2DM patients (n:25) were compared for clinical and laboratory parameters. Results: In MODY(+) subjects, mutations in GCK (MODY 2) (n:12; 40%) were the most common followed by HNF4A (MODY 1) (n:4; 13.3%). Diabetes diagnosis age was younger in MODY(+) group but not statistically significant. Sixty-six percent of MODY(+) subjects had diabetes history at 3-consecutive generations in their family compared with 28% of T2DM patients statistically significant (p:0.006). Gender, BMI, C-peptide, HbA1c, lipid parameters, creatinine, GFR, microalbuminuria, vitamin D and calcium were not statistically different between the groups. Conclusion: According to present study results, MODY mutation positivity is most probable in young autoantibody (-) diabetic patients diagnosed before 30 years of age, who have first degree family history of diabetes.

Screening for Mutations of MODY 1-5 Genes in Chinese Families with Early-onset Type 2 Diabetes / 中山大学学报(医学科学版)

[Objective] The aim of our study was to seek the mutations in MODY1～5 genes in Chinese population by direct sequencing in probands from families with early-onset type 2 diabetes.[Methods] Variants screening in MODY 1-5 genes were performed by PCR and direct sequencing in 19 probands from early-onset type 2 diabetes families.[Results] We found no mutation but many polymorphisms.There were 6,5,15,1,and 1 variants in MODY 1-5 genes respectively.[Conclusion] Our negative results in MODY genes suggest the genetic heterogeneity of different populations.Mutations in MODY 1-5 genes might not be the cause of diabetes in those 19 families.