Congenital muscular dystrophy (CMD), which is present from birth, results in generalized weakness, and usually progresses slowly.
A subtype, called Fukuyama CMD, also involves mental retardation.
Several of the muscular dystrophies, including DMD, BMD, CMD, and most forms of LGMD, are due to defects in the genes for a complex of muscle proteins.
Some forms of LGMD and DD exhibit this pattern of inheritance, as does CMD.
Nonetheless, a child with CMD may learn to walk, either with or without some assistive device, and live into young adulthood or beyond.
In contrast, children with Fukuyama CMD are rarely able to walk and have severe mental retardation.