Fukuyama Congenital Muscular Dystrophy

Fukuyama congenital muscular dystrophy (FCMD), also known as FKTN-related Walker-Warburg Syndrome, is an extremely severe inherited disorder that affects muscle, brain, and eye development. Individuals with this disorder will typically have severe eye and brain abnormalities that are present at birth, as well as seizures and intellectual disability that develop later in infancy. It causes progressive muscle wasting and muscle weakness very early in life. Children affected with this disorder will not typically survive past age 3. Currently, there is no cure for this disorder but medical surveillance and care may help to improve some symptoms and overall condition of life. FCMD is caused by pathogenic variants in the FKTN gene.

FCMD is inherited in an 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 FCMD. However, the risk to have a child affected with FCMD is increased. Testing of reproductive partners is recommended for carriers of FCMD.

Walker-Warburg Syndrome affects 1 in 60,500 newborns worldwide. FKTN-related WWS is more common in the Ashkenazi Jewish population.

Genetics Home Reference: Walker-Warburg Syndrome (http://ghr.nlm.nih.gov)
Rare Diseases.org: Walker-Warburg Syndrome (https://www.rarediseases.org)

OMIM [Muscular Dystrophy-Dystroglycanopathy Type A: 253800] (http://www.ncbi.nlm.nih.gov/omim)
Gene Reviews: Congenital Muscular Dystrophy Overview (http://www.ncbi.nlm.nih.gov/books/NBK1116/)

• Full gene sequencing