[Estimation of the probability of heterozygosity in Duchenne-type progressive muscular dystrophy].

The severe Duchenne type of muscular dystrophy is inherited as an X-linked recessive trait. Approximately two thirds of healthy female heterozygous carriers have a high serum creatine kinase (SCK). A suspected carrier with a normal SCK level therefore, presents an important problem in genetic counselling. Based on Bayesian methods, Emery and Hollyway derived a formula which is applicable when the sporadic case is either the son or brother of a consultant and which also includes information on SCK levels in the consultant and in normal daughters and sisters. The present paper describes the results obtained with use of this formula in 27 families with at least a propositus with Duchenne muscular dystrophy.