NORD gratefully acknowledges Chang-Yong Tsao, MD, FAAN, FAAP, Professor of Clinical Pediatrics and Neurology, College of Medicine and Public Health, Ohio State University, for assistance in the preparation of this report.
Fukuyama type congenital muscular dystrophy (FCMD) is one of several forms of a rare type of muscular dystrophy known as congenital muscular dystrophy. It is inherited as an autosomal recessive trait. Symptoms of this disorder are apparent at birth and progress slowly. In addition to general muscle weakness and deformities of the joints (contractures), FCMD is often accompanied by seizures, intellectual disability, and speech problems. This disorder is predominantly found in Japan.
Infants with Fukuyama congenital muscular dystrophy are “floppy” at birth and usually have problems sucking and swallowing. They have a weak cry and there is a loss of muscle tone as well as weakness of the muscles. The joints in the knees and elbows may be in a fixed position (contractures) and reflexes of the tendons are poor.
Mental retardation is characteristic of this form of muscular dystrophy. Also, some affected infants and children have seizures. A sunken chest, and a severe form of grand mal seizures called status epilepticus has been found in a few individuals with FCMD.
Fukuyama congenital muscular dystrophy is inherited as an autosomal recessive trait. It occurs as a result of a mutation in the gene that gives instructions for the production of (codes for) a protein known as fukutin. The normal role of this protein isn’t yet well understood.
Genetic diseases are determined by the combination of genes for a particular trait that are on the chromosomes received from the father and the mother.
Recessive genetic disorders occur when an individual inherits two copies of an abnormal gene for the same trait, one from each parent. If an individual inherits one normal gene and one gene for the disease, the person will be a carrier for the disease but usually will not show symptoms. The risk for two carrier parents to both pass the altered gene and have an affected child is 25% with each pregnancy. The risk to have a child who is a carrier like the parents is 50% with each pregnancy. The chance for a child to receive normal genes from both parents is 25%. The risk is the same for males and females.
Parents who are close relatives (consanguineous) have a higher chance than unrelated parents to both carry the same abnormal gene, which increases the risk to have children with a recessive genetic disorder.
Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary to cause a particular disease. The abnormal gene can be inherited from either parent or can be the result of a new mutation (gene change) in the affected individual. The risk of passing the abnormal gene from an affected parent to an offspring is 50% for each pregnancy. The risk is the same for males and females.
In some individuals, the disorder is due to a spontaneous (de novo) genetic mutation that occurs in the egg or sperm cell. In such situations, the disorder is not inherited from the parents.
Fukuyama type congenital muscular dystrophy is almost nonexistent in the United States, but in Japan is second only to Duchenne muscular dystrophy in frequency. The incidence in Japan is reported as about 0.7-1.2 cases per 100,000 children.
The diagnosis depends on a thorough physical examination and medical history. In addition, the physician will look for information to assist in the diagnosis from several tests such as blood tests to detect abnormally high levels of a particular enzyme (creatine kinase) released form the cells of damaged muscles, and blood fukutin gene mutations, electromyographic studies to determine the area of muscle that is damaged, and muscle biopsy to distinguish muscular dystrophy from other neuromuscular disorders.
Treatment
Patients with Fukuyama congenital muscular dystrophy may benefit from physical therapy to help prevent joints from becoming fixed.
For patients who have seizures, anti-convulsant drugs such as phenytoin, valproic acid, phenobarbitol, clonazepam, ethusuximide, primidone, corticotropin, and corticosteroid drugs may help prevent and control seizures.
Genetic counseling will be of benefit for patients and their families.
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: [email protected]
Some current clinical trials also are posted on the following page on the NORD website:
https://rarediseases.org/for-patients-and-families/information-resources/info-clinical-trials-and-research-studies/
For information about clinical trials sponsored by private sources, contact:
www.centerwatch.com
For information about clinical trials conducted in Europe, contact:
https://www.clinicaltrialsregister.eu/
Contact for additional information about Fukuyama type congenital muscular dystrophy:
Chang-Yong Tsao, MD, FAAN, FAAP
Professor of Clinical Pediatrics and Neurology
Nationwide Children’s Hospital
College of Medicine
Ohio State University
Columbus, Ohio 43210
614-722-4625
[email protected]
TEXTBOOKS
Rowland LP, ed. Merritt’s Neurology. 10th ed. Lippincott Williams & Wilkins. Philadelphia, PA. 2000:746.
Adams RD, Victor M, Ropper AA, eds. Principles of Neurology. 6th ed. McGraw-Hill Companies. New York, NY; 1997:1427.
Menkes JH, Pine Jr JW, et al., eds. Textbook of Child Neurology. 5th ed. Williams & Wilkins. Baltimore, MD; 1995:832, 843.
REVIEW ARTICLES
Grewal PK, Hewitt JE. Glycosylation defects: a new mechanism for muscular dystrophy? Hum Mol Genet. 2003;12 Spec No 2:R259-64.
Toda T, Kobayashi K, Takeda S, et al. Fukuyama-type congenital muscular dystrophy (FCMD) and alpha-dystroglycanopathy. Congenit Anom. (Kyoto). 2003;97-104.
Martin-Rendon E, Blake DJ. Protein glycosylation in disease: new insights into the congenital muscular dystrophies. Trends Pharmacol Sci. 2003;24:178-83.
JOURNAL ARTICLES
Yamamoto T, Kato Y, Karita M, et al. Expression of genes related to muscular dystrophy with lissencephaly. Pediatr Neurol. 2004;31:183-90.
Kato R, Kawamura J, Sugawara H, et al. A rapid diagnostic method or a retrotransposal insertional mutation into the FCMD gene in Japanese patients with Fukuyama congenital muscular dystrophy. Am J Med Genet A. 2004;127:54-57.
Takeda S, Kondo M, Sasaki J, et al. Fukutin is required for maintenance of muscle integrity, cortical histiogenesis and normal eye development. Hum Mol Genet. 2003;12:1449-59.
Saito Y, Kobayashi M, Itoh M, et al. Aberrant neuronal migration in the brainstem of Fukuyama-type congenital muscular dystrophy. J Neuropathol Exp Neurol. 2003;62:497-508.
Taniguchi K, Kobayashi K, Saito K, et al. Worldwide distribution and broader clinical spectrum of muscle-eye-brain disease. Hum Mol Genet. 2003;12:527-34.
INTERNET
Lopate G. Congenital Muscular Dystrophy.Medscape. http://emedicine.medscape.com/article/1180214-overview Updated: Dec 24, 2015. Accessed March 5, 2018.
Facts About Rare Muscular Dystrophies. MDA Publications. https://www.mda.org/sites/default/files/publications/Facts_RareMDs_P-214_0.pdf Updated December 2009. Accessed March 5, 2018.
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