A synonymous variant in GCK gene as a cause of gestational diabetes mellitus

The diagnosis of MODY as a subtype of gestational diabetes mellitus (GDM) is important for an adequate management during pregnancy and the postnatal period. The present report describes a case of GDM caused by a synonymous с.666C>G р.V222V substitution in the GCK gene. The variant, which was initially ranked as ‘likely benign’, was later proven to be pathogenic by in vitro studies. The с.666C>G substitution led to the use of a new donor splice site and synthesis of the aberrant mRNA with deletion of 16 base pairs. The case illustrates that additional clinical and experimental data may be required for the correct interpretation of sequence variants pathogenicity

Erratum: a synonymous variant in GCK gene as a cause of gestational diabetes mellitus (diabetes mellitus. 2019;22(2). Doi: 10.14341/dm9938)

An erratum on «A synonymous variant in GCK gene as a cause of gestational diabetes mellitus» by Natalya A. Zubkova, Petr M. Rubtsov, Liudmila I. Ibragimova, Nina A. Makretskaya, Evgeny V. Vasiliev, Vasily M. Petrov, Anatoly N. Tiulpakov (2019). Diabetes mellitus. 22(2). doi: 10.14341/DM9938An error was made in the list of authors: Fatima F. Burumkulova was not indicated as author of this article. The correct list of authors: Natalya A. Zubkova, Petr M. Rubtsov, Fatima F. Burumkulova, Liudmila I. Ibragimova, Nina A. Makretskaya, Evgeny V. Vasiliev, Vasily M. Petrov, Anatoly N. Tiulpakov.The editorial board apologize for this error and state that this does not change the scientific conclusions of the article in any way.The original article has been updated

Birth weight and length in offsprings of mothers with gestational diabetes mellitus due to mutations in GCK gene

Background. Gestational diabetes (GDM) due to GCK gene mutations is the most frequent form of monogenic diabetes mellitus (DM) presenting during pregnancy. It has been suggested that the use of insulin in pregnancies with fetuses carrying GCK mutations may lead to intrauterine growth retardation. In the present study we evaluated the effect of insulin therapy during pregnancy on birth weight and length in the offsprings of mothers with GDM due to GCK mutations. Aims. The aim was to study birth weight and length in offsprings of mothers with gestational diabetes mellitus due to mutations in GCK, depending on the therapy during pregnancy. Materials and methods. The study included 38 patients with GDM caused by GCK gene mutations (18.7%) and the 45 offsprings. To define molecular basis of GDM in pregnant women we used a targeted NGS. Diabetes panel genes were sequenced using a custom Ion Ampliseq gene panel and PGM semiconductor sequencer (Ion Torrent). To found the same mutations in their offsprings was used Sanger sequencing. All children were divided into 3 groups depending of their genotype and therapy received by the mothers during pregnancy. Results. We found statistically significant differences in birth length (p=0.04) and weight (p=0,031) depending on the genotype of the child and therapy in the mother. The risk of macrosomia was shown in non-mutation-carrying offsprings only. The birth weight in children with GCK gene mutations whose mothers received insulin during pregnancy was significantly lower. However, the birth weight remained in the normal range. Conclusions. Since prenatal diagnostics in the mothers with GCK gene mutations is not always justified, we recommend insulin therapy in order to prevent fetal macrosomia, which, however, should be less aggressive than in GDM due to other causes

Mutations in transcription factor as rare causes of diabetes in pregnancy

MODY1 and MODY3 represent rare causes of diabetes in pregnancy. Establishing a molecular diagnosis of MODY1 or MODY3 during pregnancy may be important for minimizing risk of perinatal complications and for improving glycemic control after pregnancy. The objective of the study was to evaluate the contribution of mutations in HNF4A and HNF1A genes in development of diabetes in pregnancy and to describe clinical characteristics of diabetes in pregnancy associated with these mutations. 230 pregnant women (20-43 years) with different type of glucose intolerance complicated during their current pregnancy were included in the study. A custom NGS panel targeting 28 diabetes causative genes was used for sequencing. Heterozygous mutations in HNF4A and HNF1A genes were detected in 3% of cases. Mutations p.I271T in HNF4A gene and p.L148F, p.Y265C, p.G288W in HNF1A gene were novel. This study includes a description of patients with pregnancy diabetes due to mutations in hepatocyte nuclear factors