Jokela type spinal muscular atrophy

A rare form of spinal muscular atrophy

Template:Medical condition (new)

Jokela type spinal muscular atrophy is a rare genetic disorder characterized by progressive muscle weakness and atrophy, primarily affecting the proximal muscles. It is a form of spinal muscular atrophy (SMA), which is a group of inherited diseases that cause muscle degeneration and weakness due to the loss of motor neurons in the spinal cord and brainstem.

Genetics

Jokela type spinal muscular atrophy is inherited in an autosomal recessive pattern, meaning that an individual must inherit two copies of the mutated gene, one from each parent, to be affected by the disorder. The specific genetic mutation responsible for this type of SMA has been identified in the CHCHD10 gene, which plays a role in mitochondrial function and maintenance.

Pathophysiology

The mutation in the CHCHD10 gene leads to mitochondrial dysfunction, which in turn causes the degeneration of motor neurons. This degeneration results in the characteristic muscle weakness and atrophy seen in affected individuals. The proximal muscles, which are closer to the center of the body, such as those in the shoulders, hips, and thighs, are typically more affected than distal muscles.

Clinical Features

Individuals with Jokela type spinal muscular atrophy typically present with symptoms in early adulthood, although the age of onset can vary. Common symptoms include:

• Progressive muscle weakness
• Muscle atrophy
• Difficulty walking or climbing stairs
• Fatigue
• Muscle cramps

The progression of the disease can vary, with some individuals experiencing a slow progression of symptoms, while others may have a more rapid decline in muscle function.

Diagnosis

Diagnosis of Jokela type spinal muscular atrophy is based on clinical evaluation, family history, and genetic testing. Genetic testing can confirm the presence of mutations in the CHCHD10 gene, which is diagnostic for this condition. Electromyography (EMG) and nerve conduction studies may also be used to assess the extent of muscle and nerve involvement.

Management

There is currently no cure for Jokela type spinal muscular atrophy, and treatment is primarily supportive. Management strategies may include:

• Physical therapy to maintain muscle strength and flexibility
• Occupational therapy to assist with daily activities
• Assistive devices such as braces or wheelchairs
• Nutritional support to maintain a healthy weight

Prognosis

The prognosis for individuals with Jokela type spinal muscular atrophy varies depending on the severity of the symptoms and the rate of disease progression. Some individuals may maintain a relatively good quality of life with appropriate management, while others may experience significant disability.

Related pages

• Spinal muscular atrophy
• Motor neuron disease
• Genetic disorders