What are the other Names for this Condition? (Also known as/Synonyms)
- Cerebromuscular Dystrophy (Fukuyama Type)
- Congenital Muscular Dystrophy (Progressive with Mental Retardation)
- Micropolygyria with Muscular Dystrophy
What is Fukuyama Type Congenital Muscular Dystrophy? (Definition/Background Information)
- Fukuyama Type Congenital Muscular Dystrophy (FCMD) is a rare form of muscular dystrophy. It primarily affects the brain, muscles, and eyes, and is inherited genetically as an autosomal recessive trait (both parents are carriers of the condition)
- Typically, such muscular dystrophies are a group of genetic conditions that can cause muscle wasting and weaknesses from an early age. Signs of Fukuyama Type Congenital Muscular Dystrophy are visible from infancy and include poor feeding, weak muscle tone, weak cry, and droopy eyelids
- FCMD can also cause impairment in the brain. Individuals with this condition have a brain abnormality referred to as ‘cobblestone lissencephaly’. This abnormality creates a bumpy, patchy appearance of the brain that resembles cobblestones
- A diagnosis of this disorder can be made through medical history and physical exams with other blood tests and procedures to assist in the diagnosis
- The treatment of Fukuyama Type Congenital Muscular Dystrophy includes physical therapy to prevent fixed joints, the administration of anticonvulsant drugs
- The outcome of Fukuyama Type Congenital Muscular Dystrophy is dependent on several factors. It depends on the severity of complications, such as cardiac, respiratory, or neurologic defects; however, the prognosis is generally poor
Who gets Fukuyama Type Congenital Muscular Dystrophy? (Age and Sex Distribution)
- Individuals of all ages, races, ethnic groups, and both gender can be affected by Fukuyama Type Congenital Muscular Dystrophy
- In Japan, the incidence reports a higher prevalence of 0.7 to 1.2 cases per every 100,000 children
What are the Risk Factors for Fukuyama Type Congenital Muscular Dystrophy? (Predisposing Factors)
- The main risk factor for Fukuyama Type Congenital Muscular Dystrophy is having a family history of the condition
It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.
Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.
What are the Causes of Fukuyama Type Congenital Muscular Dystrophy? (Etiology)
- Fukuyama Type Congenital Muscular Dystrophy is inherited in an autosomal recessive manner
- The cause of this disorder is a mutation in the gene that instructs the production of fukutin, a type of protein. This mutation is located on chromosome 9
- A mutation in the gene coding for the protein fukutin is the main cause behind this disorder
Autosomal recessive: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children, born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).
What are the Signs and Symptoms of Fukuyama Type Congenital Muscular Dystrophy?
The signs and symptoms of Fukuyama Type Congenital Muscular Dystrophy are recognizable from infancy. Infants with this condition may have the following features:
- Problems with suckling and swallowing
- A loss of muscle tone; weak muscles
- Weak cries
- Fixed joints of the knees or elbows; poor tendon reflexes
- Mental retardation
- Frequent seizures; some individuals can even be affected by status epilepticus, a form of grand mal seizures
How is Fukuyama Type Congenital Muscular Dystrophy Diagnosed?
A diagnosis of Fukuyama Type Congenital Muscular Dystrophy may be undertaken as follows:
- A thorough physical examination and medical history examination
- Blood tests to check if there is a high level of creatine kinase, an enzyme released from damaged muscle cells
- Electromyographic studies to determine the region of muscle that is affected
- Muscle biopsy to differentiate muscular dystrophy from other neuromuscular disorder
- Genetic testing, such as linkage, deletion, and sequence analysis, can be done to diagnose Fukuyama Type Congenital Muscular Dystrophy
Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.
What are the possible Complications of Fukuyama Type Congenital Muscular Dystrophy?
- Fukuyama Type Congenital Muscular Dystrophy particularly affects the brain, eyes, and muscles. It impairs development of the skeletal muscles, which leads to weaknesses and even deformed appearances
- FCMD can also cause serious brain development complications. Brain evolution can be affected, damaging cognitive functioning as well as social skills. It can also lead to mental retardation
How is Fukuyama Type Congenital Muscular Dystrophy Treated?
Currently, this Fukuyama Type Congenital Muscular Dystrophy has no known cures and no successful treatments exist. The following treatments are available though:
- Treatments to delay muscle breakdown and increase life expectancy, such as through physical therapy and stretching to increase mobility or benefit the muscles, may be attempted
- Individuals with seizures may be given anticonvulsant drugs and corticosteroid drugs, which may help prevent seizures
- Respiratory assistance
- ACE inhibitors and beta-blockers can provide assistance in treating heart conditions
- Treatment may also include orthopedic surgery or other orthopedic techniques to correct skeletal abnormalities
- Genetic counseling: It can offer help to individuals with FCMD and their families by planning out for the future
How can Fukuyama Type Congenital Muscular Dystrophy be Prevented?
- Currently, there are no specific methods or guidelines to prevent Fukuyama Type Congenital Muscular Dystrophy, since it is a genetic condition
- Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
- If there is a family history of the condition, then genetic counseling will help assess risks before planning for a child
- Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders such as Fukuyama Type Congenital Muscular Dystrophy
- Regular medical screening at periodic intervals with tests and physical examinations are strongly recommended
- Some preventative measures include physical therapy and stretching to loosen the muscles, and taking prescriptive medications such as muscle relaxants
What is the Prognosis of Fukuyama Type Congenital Muscular Dystrophy? (Outcomes/Resolutions)
In general, Fukuyama Type Congenital Muscular Dystrophy has a poor prognosis.
- Most children with this form of muscular dystrophy have limited mobility (may only be able to sit upright and slide)
- Heart abnormalities are known to continually increase in severity and worsen
- In most individuals, the mental development is impaired
The effect of complications due to Fukuyama Type Congenital Muscular Dystrophy is that children rarely live through adolescence; most individuals die by or before they reach the age of 20 years.
Additional and Relevant Useful Information for Fukuyama Type Congenital Muscular Dystrophy:
FCMD is very common in Japan. One out of every 90 people in Japan is a heterozygous carrier of this disorder.