Endocrine Abstracts

A 37-year-old Caucasian female, pharmacist, referred to Diabetological center in February 2017. The main complaint was frequent urination.

Medical history: She was diagnosed with T2DM at the age of 32 year. She was taking Metformin 850 mg twice daily. Her plasma glucose was 7.8 mmol/l at fasting; 10.8 mmol/l postprandial.

Family history: Her father has elevated glucose levels also (up to 8 mmol/l before meal). Her mother has passed away soon after the delivery of her second child at the age of 31 year (baby died also on the second day after birth).

Patient has a 12- year- old daughter.

Physical examination: BMI is 23 kg/m² (height 157 cm, weight 56 kg)

No other NeuroD1-associated clinical phenotypes, including cerebellum hypoplasia, psychic development retardation, sensorineural bradyacuasia or visual impairment were revealed.

Laboratory findings: Her HbA1c was 5.77%, C-peptide level was 1.52 ng/ml (1.07–11.8 ng/ml); glutamate decarboxylase and pancreatic islet antibodies were negative.

The probability of patient having MODY was 58% (using Diabetes Diagnostics calculator by Exeter University).

Patient`s daughter glycemia was 9.8 mmol/l at random site. She had not been diagnosed with diabetes mellitus previously. Her HbA1c was 6.3%, C- peptide level was 1.96 ng\ml (1.07–11.8 ng/ml); glutamate decarboxylase, zinc transporter 8 and IA-8 antibodies were negative. The results of the oral glucose tolerance test were 6.4 mmol/l at fasting, 12.3 mmol/l after 30 minutes, 15.3 mmol/l after 60 minutes, 13.6 mmol/l after 120 minutes.

In July 2017 the mutation in the neurogenic differentiation factor 1 gene (NeuroD1) was revealed in both patients (a heterozygous undescribed previously mutation variant c. 1022A > T: p. H341L. The analysis was performed at The National Endocrinology Research Centre. Moscow) The diagnosis of MODY6 was established.

To the date both patients take no medication. Their blood glucose levels are 6–7 mmol/l at fasting, 6–8 mmol/l after the meal.