The disease ranges in severity from very mild to considerably disabling, with impairment of walking, chewing, swallowing and speaking. About half of those with the disorder retain the ability to walk throughout their lives. Orthopedic supports can be helpful early in the progression of the disease, and surgery is sometimes done to improve function in the shoulder area. One form that has been clearly described is Fukuyama congenital muscular dystrophy. This disorder involves severe weakness of the facial and limb muscles and a generalized lack of muscle tone, usually appearing before 9 months.
Joint contractures are common.
Brain abnormalities are also present, and most children have severe mental and speech problems. Seizures are often part of the disease, and medications are prescribed for these. Physical therapy is needed to minimize the contractures. The disease has been linked to a gene defect on chromosome 9, although the precise gene and its protein are so far unknown. Another form of congenital dystrophy seems to be related to a deficiency or malfunction of the protein merosin, which normally lies outside muscle cells and links them to the surrounding tissue.