Muscular Dystrophy and Eye Defects

photo by Look Into My Eyes

Facioscapulohumeral muscular dystrophy (FSHD) is a degenerative disease causing the weakening of muscles in the face, shoulders, and upper arms. The disease usually manifests itself by the age of 20 and progresses slowly, with occasional stages of rapid deterioration. As an autosomal dominant disorder, FSHD is caused by a DNA deletion in chromosome 4. In addition to the weakening of muscles, many with the disorder experience vision problems due to abnormal blood vessel formation in the eyes.

About 95% of those affected show a defect in the expression of FRG1, a gene which aids in skeletal muscle development in frogs as well as humans. Researchers at the University of Illinois decided to determine if the FRG1 gene was also responsible for the defective angiogenesis in the eye of FSHD patients. They determined that the FRG1 gene product was highly expressed in the blood vessels of frogs and is important for proper vessel growth and organization. Thus the lack of this gene would account for abnormalities seen in the eye of humans, which was further shown by the study. Aberrant FRG1 expression therefore leads to defective skeletal muscle development and angiogenesis of the eye, both hallmarks of FSHD.

Source: Science Daily- Researchers Identify Gene Associated With Muscular Dystrophy-related Vision Problems