What is Fukuhara Syndrome?
Fukuhara Syndrome is an extremely rare pathological condition which begins in childhood and affects primarily the nervous and the skeletal systems, although other systems of the body may also get affected as a result of Fukuhara Syndrome. The primary presenting feature of Fukuhara Syndrome is the distinct involuntary jerking of the arms and legs and in some cases even the entire body starts shaking. Muscle weakness is yet another symptom that children with Fukuhara Syndrome tend to have which is a distinguishing feature of this condition.
Additionally, children with Fukuhara Syndrome also have impaired coordination, ataxia, seizures, and a gradual but progressive deterioration of their functional skills along with gradual degeneration of the optic nerve causing visual impairment, hearing deficits, and peripheral neuropathy as a result of Fukuhara Syndrome.
What are the Causes of Fukuhara Syndrome?
The root cause of Fukuhara Syndrome is mutations in mitochondrial DNA. These faulty genes are usually inherited by the mother of the affected individual and these mutated genes are lost in the sperm cells and hence cannot be inherited by the father.
The affected can pass the genes to her children but further inheritance of this condition will only take place through the daughters of the affected mother and not the sons. Mitochondrial are essential for the human body for energy and other important functions that are required for regular functioning of the human body.
Until and unless the mutations outnumber the normal mitochondrial DNAs the affected individual will show no symptoms of Fukuhara Syndrome. The main gene responsible for development of Fukuhara Syndrome is the MT-TK gene, although de novo mutations have also been responsible for the development of Fukuhara Syndrome.
What are the Symptoms of Fukuhara Syndrome?
The symptoms of Fukuhara Syndrome start to show up in early childhood of the individual, although in some cases symptoms may not be apparent till adolescence. The symptoms of Fukuhara Syndrome are quite variable and members of the same family if affected will show different symptoms as a result of Fukuhara Syndrome.
The primary symptom of Fukuhara Syndrome is myoclonus or involuntary jerking of the upper and lower extremities and in some severe cases even the entire body. Seizures, ataxia, muscle weakness and dementia are some of the other symptoms that are commonly seen in individuals with Fukuhara Syndrome.
Additionally, affected individuals are of short stature and tend to have optic nerve degeneration affecting vision of the individual along with hearing deficit and altered sensation in some parts of the body. Lactic acidosis is a condition which is commonly seen in individuals with Fukuhara Syndrome.
Such people tend to complain of abdominal pain, persistent fatigue and problems with breathing as a result of lactic acidosis caused by Fukuhara Syndrome.
How is Fukuhara Syndrome Diagnosed?
The front line method for diagnosis of Fukuhara Syndrome is genetic testing done to see mutations in the Mt-TK gene and abnormalities in the mitochondrial DNA. This will more or less confirm the diagnosis of Fukuhara Syndrome. Additionally, a lab test will reveal increased levels of lactic acid which will further cement the diagnosis of this condition.
How is Fukuhara Syndrome Treated?
There is no cure for Fukuhara Syndrome but treatment is mainly aimed at treating the symptoms caused by it. Anticonvulsants may be used to control seizures caused by Fukuhara Syndrome.
To control the symptoms of myoclonus, levetiracetam has shown to be effective in controlling the involuntary jerking. Treatments may also be given for optic nerve degeneration and hearing aid may be of benefit for treating hearing deficits in individuals with Fukuhara Syndrome.
Additionally, physical therapy and exercises directed towards increasing the energy level of the patient and slow down the process of the condition has also been quite effective in individuals with Fukuhara Syndrome.