Macrothrombocytopenia progressive deafness

Macrothrombocytopenia with progressive deafness is a rare genetic disorder characterized by the presence of abnormally large platelets (macrothrombocytopenia) and a progressive loss of hearing (deafness). This condition is inherited in an autosomal dominant manner, meaning that only one copy of the altered gene in each cell is sufficient to cause the disorder. The gene implicated in this condition is the MYH9 gene, which provides instructions for making a protein that is involved in cell movement and attachment, as well as in the formation of platelets.

Symptoms and Diagnosis

The primary symptoms of macrothrombocytopenia with progressive deafness include large platelets, which can be observed under a microscope, and a progressive hearing loss that typically begins in childhood or adolescence. The hearing loss is sensorineural, meaning it results from damage to the inner ear or to the nerve pathways from the inner ear to the brain. Individuals with this condition may also experience other symptoms related to MYH9-related disorders, such as kidney problems or cataracts in some cases.

Diagnosis of macrothrombocytopenia with progressive deafness is based on clinical examination, family history, and laboratory tests that show the presence of large platelets. Genetic testing can confirm the diagnosis by identifying a mutation in the MYH9 gene.

Treatment

There is no cure for macrothrombocytopenia with progressive deafness. Treatment focuses on managing symptoms and may include hearing aids or cochlear implants for hearing loss. Regular monitoring of kidney function and eye examinations are recommended for individuals with this condition due to the potential for related complications. In some cases, individuals may require interventions to manage bleeding episodes due to the platelet abnormalities.

Genetics

The MYH9 gene mutations that cause macrothrombocytopenia with progressive deafness affect the production or function of the nonmuscle myosin heavy chain IIA protein. This protein plays a key role in cell shape, movement, and division. It is also essential for the development and function of platelets. The specific mutations in the MYH9 gene lead to the production of an abnormal protein that disrupts normal platelet formation and function, resulting in the characteristic large platelets seen in this condition.

Epidemiology

Macrothrombocytopenia with progressive deafness is a rare condition, though the exact prevalence is unknown. It is one of several disorders associated with mutations in the MYH9 gene, collectively known as MYH9-related disorders.

See Also

• Genetic disorder
• Hearing loss
• Platelet