Genetic linkage between the loci for colour blindness and Duchenne type muscular dystrophy.

Duchenne type muscular dystrophy is a condition which begins in infancy or early childhood, and is characterized by progressive muscle weakness leading to death in the late teens or early twenties (Walton and Nattrass, I954). This type of muscular dystrophy has been variously referred to as 'pseudo- hypertrophic muscular dystrophy' (Bell, I948), 'progressive muscular dystrophy of childhood' (Stephens and Tyler, 195i), and 'rapidly progressive muscular dystrophy of young boys' (Stevenson, I953). This type of muscular dystrophy will be referred to here as Duchenne type muscular dystrophy, in agreement with the suggestion made by Walton (I955, 1957) that this is probably the best designation for that type of muscular dystrophy which affects young boys and is inherited as an X-linked recessive trait.