Fukuyama congenital muscular dystrophy (Fukuyama congenital muscular dystrophy) - Gen FKTN.
Congenital muscular dystrophy Fukuyama is an inherited disease that primarily affects the skeletal muscles, brain and eyes. Congenital muscular dystrophies are a group of genetic disorders that cause muscle weakness and atrophy.
The first signs of the disease appear in early childhood and include a weak cry, poor diet and hypotonia. Often, weakness of facial muscles leads to ptosis and mouth open. In childhood, muscle weakness and contractures restrict movement and interfere with the development of motor skills such as sitting, standing and walking. This disease also affects brain development. Affected individuals have a brain disorder called lissencephaly in Cobble, in which an uneven appearance on the surface of the brain develops. These changes in brain structure provocam a delay in the development of speech and motor skills and moderate to severe intellectual disabilities. Most children with congenital muscular dystrophy Fukuyama fail to be able to stand or walk, although some may sit unsupported and glide across the floor in a sitting position. More than half of all affected children also have seizures.
Other signs and symptoms of the disease include other eye abnormalities and heart problems progressing slowly after 10 years. As the disease progresses, affected individuals may develop swallowing difficulties that can lead to pneumonia. Due to the serious associated medical problems, most people survive until late childhood or adolescence.
This process is due to mutations in the gene FKTN, located on the long arm of chromosome 9 (9q31.2). This gene codes fukutin protein. Although the exact function of this protein is unclear, it is believed that this protein may chemically modified a protein called alpha-dystroglycan. This protein anchor cells to the extracellular matrix that surrounds it . In skeletal muscle, ?-dystroglycan helps stabilize and protect the muscle fibers. In the brain, this protein helps direct the migration of neurons during early development.
Virtually all people with congenital muscular dystrophy Fukuyama due to mutations in the gene FKTN have an insert of about 3,000 nucleotides (3 kilobases) in FKTN gene. This insertion occurs at a part of the gene known as the untranslated region 3 ', which helps regulate gene activity. This mutation in the gene FKTN, reduces the amount of fukutin encoded within cells. A deficiency prevents normal fukutin probably ?-dystroglycan modification which disrupts the normal function of the protein. No ?-dystroglycan to stabilize functional muscle cells, muscle fibers are damaged. Damaged fibers weaken and eventually die, leading to progressive weakness and atrophy of skeletal muscles. ?-dystroglycan defective also affects the migration of neurons during early development of the brain, causing some neurons migrate beyond the brain surface in the space surrounding liquid. It is believed that this alteration in neuronal migration cause lissencephaly in Cobble in children with congenital muscular dystrophy Fukuyama.
This disease is inherited in an autosomal recessive pattern, that is, both copies of the gene in every cell must have mutations for alteration is expressed. The parents of an individual with an autosomal recessive disease have a copy of the mutated gene, but usually show no signs and symptoms of the disease.
Tests in IVAMI: in IVAMI perform detection of mutations associated with congenital muscular dystrophy Fukuyama, by complete PCR amplification of exons FKTN gene, and subsequent sequencing.
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).