Distal Hereditary Motor Neuropathy Type V

Distal Hereditary Motor Neuropathy Type V (DHMN-V), also known as Spinal Muscular Atrophy, is a rare genetic disorder characterized by progressive distal muscle weakness and atrophy. It is a subtype of Distal Hereditary Motor Neuropathies (DHMN), a group of inherited, progressive, motor neuron diseases that primarily affect the distal muscles of the limbs.

Etiology[edit | edit source]

DHMN-V is caused by mutations in the GARS gene, which provides instructions for making an enzyme called glycyl-tRNA synthetase. This enzyme is involved in the process of protein production within cells. Mutations in the GARS gene disrupt this process, leading to the death of motor neurons and the subsequent muscle weakness and atrophy seen in DHMN-V.

Clinical Features[edit | edit source]

The primary symptom of DHMN-V is progressive weakness and wasting (atrophy) of the distal muscles of the limbs. This typically begins in the hands and feet and gradually spreads to the arms and legs. Other symptoms may include difficulty walking, loss of fine motor skills, and muscle cramps. The severity and progression of symptoms can vary widely among affected individuals.

Diagnosis[edit | edit source]

Diagnosis of DHMN-V is based on clinical examination, family history, and genetic testing. Electromyographic (EMG) studies and nerve conduction studies may also be used to confirm the diagnosis.

Treatment[edit | edit source]

There is currently no cure for DHMN-V. Treatment is supportive and aims to manage symptoms and improve quality of life. This may include physical therapy, occupational therapy, and the use of assistive devices such as braces or wheelchairs.

Prognosis[edit | edit source]

The prognosis for individuals with DHMN-V varies. Some individuals may have a normal lifespan with mild disability, while others may experience significant disability and reduced lifespan.