Gastrointestinal tract symptoms in maternally inherited diabetes and deafness (MIDD)

Objective: To evaluate the prevalence and clinical consequences of gastro-intestinal manifestations in Maternally Inherited Diabetes and Deafness syndrome (MIDD). Methods: We report the case of fatal intestinal peudo-obstruction in a patient with severe MIDD. Using a standardized questionnaire, we evaluate the frequency of gastrointestinal tract (GIT) symptoms in 10 patients with MIDD (8 A3243G and 2 T14709C mutations of mitochondrial DNA). The reference population consisted of 50 patients with type 1 diabetes matched for disease duration. In 4 patients with digestive manifestations endoscopic examination of upper and lower GIT was performed allowing multiple biopsies for ultrastrutural and molecular analysis. Results: GIT symptoms were frequently reported in MIDD specially in patients bearing the mt 3243 mutation. The manifestations i.e. constipation, diarrhea or both, were more frequent in this subgroup than in type 1 diabetic population (88% vs 28%, p < 0.05). Ileus is a rare and severe complication with a frequent fatal issue. Ultrastructural analysis of the mucosa from oesophagus, stomach, duodenum, colon and rectum showed mild modifications such as accumulation of normal mitochondria and lipid droplets. Heteroplasmy levels were determined in 4 patients harboring the 3243 mutation. In three patients the percentage of mutated DNA increased from upper to lower GIT. Conclusions: Gastrointestinal symptoms are frequent in MIDD secondary to 3243 mutation. They might explain the lower body weight observed in these patients in comparison to reference diabetic populations. They can also lead to a severe complication namely the intestinal pseudo-obstruction.