Abstract
OBJECTIVE: To assess the family history of diabetes in non-insulin dependent diabetes mellitus with particular emphasis on parental phenotype. DESIGN: Family histories were obtained from an existing computerised database and supplemented by postal questionnaires. SETTING: Diabetic service of a provincial teaching hospital. SUBJECTS: A total of 1326 patients with non-insulin dependent diabetes who had been referred to diabetic clinics over the past 10 years and from whom data had been collected for inclusion in the database, of whom 347 had affected first degree relatives. Nineteen non-white patients were excluded because of the differential hereditability of the disease, and 230 (70%) patients with an affected first degree relative responded to the postal questionnaire. RESULTS: Mothers were implicated in significantly more cases than fathers in patients with a single affected parent: 125 mothers and 48 fathers from database; 82 mothers and 34 fathers from postal questionnaire; p less than 0.001 in both cases. CONCLUSIONS: Maternal influences seem to have an important role in the inheritance of non-insulin dependent diabetes.