Gender distributions in parents and children concordant for multiple sclerosis

The family histories of 7,802 multiple sclerosis (MS) patients were reviewed with respect to the familial pattern of the disease and the gender of the affected individuals. These patients joined an epidemiological study following a call for patients on French television and answered a questionnaire with the help of their physician. 170 had an affected parent, providing 72 mother-daughter pairs, 48 mother-son pairs, 37 father-daughter pairs, and 13 father-son pairs. From these data, the maximum likelihood estimate of the female to male ratio is 2.06, which is not different from what could be expected given the ratio of 2:1 usually found among patients. The apparent deficit of father-son concordant pairs probably simply reflects the well-known preponderance of the disease among females.