The classification of diabetes mellitus in adolescents and young adults is often difficult. The diagnosis of the monogenic form of diabetes may have substantial influence on quality of life, prognosis and the choice of the appropriate treatment of affected patients. Among MODY (maturity-onset of diabetes in the young) MODY-1 is rarely detected, only 13 families were described in 2000, and 103 different mutations in 173 families were known in 2013 worldwide. The authors present the first Hungarian case of a monogenic form of diabetes due to HNF4α mutation (MODY-1). The diabetes of the index patient No. 1 (42-year-old woman with insulin treated diabetes) was diagnosed as gestational diabetes at age of 20 when she was treated with diet only. Later, insulin treatment has been initiated when marked hyperglycaemia was detected during an episode of acute pneumonia at age of 26. The diabetes of the index patient No. 2 (20-year-old daughter of the index patient No. 1, treated also with insulin) was diagnosed as type 2 diabetes at age of 13 and the patient was treated with diet only. Later the classification was modified to type 1 and insulin therapy was initiated at age of 14. The manifestation of diabetes, the familial occurrence and the low dose insulin requirement were suggestive for monogenic diabetes. Using molecular genetic method a mutation (c.869G>A, p.R290H) of HNF4α gene was found and MODY-1 was diagnosed in both cases. Insulin therapy was switched to treatment with low dose sulfanylurea and an excellent glycaemic control was achieved and sustained at follow-up of 1-year. No further positive cases were found during screening of other family members.
Keywords: MODY (maturity-onset of diabetes in the young); MODY-1; diabetes mellitus; monogenic diabetes; monogénes diabetes; sulfanylurea treatment; szulfanilureaterápia.