Background: Causes of death of patients with the 3243A>G mutation have been described in case reports or case series with a limited number of subjects.
Methods: Eighty-two maternally related sibships of 11 families with 3243A>G were included in this survey. The lifespan of each subject in these families was compared with the life expectancy of the general population, adjusted with respect to year of birth and gender. Causes of death were determined among 3243A>G carriers and their first-degree maternal relatives.
Results: We identified 123 deceased subjects in families with 3243A>G and found an excess mortality during the early years of life and young adulthood. The median age at death for 3243A>G carriers and their first-degree maternal relatives was significantly lower than that of the general population. Neurological and cardiovascular diseases made up one-third of the causes of death. Sudden and unexpected death was not uncommon in patients with cardiovascular diseases, diabetes and epilepsy.
Conclusions: 3243A>G carriers and their first-degree maternal relatives died younger than was predicted by their life expectancy at birth. Neurological disease was the most common cause of death.