Muscle-Eye-Brain Disease

Muscle-Eye-Brain disease (MEB), officially known as muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), is an inherited disorder caused by a dysfunctional enzyme called protein O-mannose beta-1,2-N-acetylglucosaminyltransferase. This condition is characterized with muscle weakness at birth, eye and vision abnormalities, including severe nearsightedness and brain abnormalities. Individuals with MEB usually have developmental delay and intellectual disability. Some affected individuals may learn how to walk and say a few words. There is no cure for MEB; however medical surveillance and care may help to improve some symptoms and overall condition of life. Life expectancy ranges from childhood into adolescence. MEB is caused by pathogenic variants in the POMGNT1 gene.

MEB is inherited in autosomal recessive manner. This type of inheritance requires the presence of two copies of a pathogenic variant in the gene for a person to have the genetic disease. Both parents must be carriers of a pathogenic variant in the gene in order to be at risk to have an affected child. The child must inherit a pathogenic variant from each carrier parent in order to be affected. There is a 1 in 4 chance that a baby will inherit two mutated copies of the gene and be affected when both parents are carriers.

There are generally no signs or symptoms associated with being a carrier for MEB. However, the risk to have a child affected with MEB is increased. Testing of reproductive partners is recommended for carriers of MEB.

MEB is estimated to affect 1 in 50,000 newborns in Finnish population. Although MEB has been reported in other populations, how often in occurs in the general population is unknown.

Genetics Home Reference: POMGNT1 (http://ghr.nlm.nih.gov/)
Genetic Alliance: Muscle eye brain disease (http://www.diseaseinfosearch.org/)

OMIM [POMGNT1:606822] (http://www.ncbi.nlm.nih.gov/omim)
Gene Reviews: Congenital muscle dystrophy (http://www.ncbi.nlm.nih.gov/books/NBK1116/)

• Full gene sequencing