Emery-Dreifuss+Muscular+Dystrophy

Posted by: Htet San =Root cause of disease: = Emery-Dreifuss muscular dystrophy is a rare genetic disease, in which the mutation can be either autosomal, recessive, or X-linked.

Affected cell types/tissues/organs/systems:
Skeletal and heart muscle tissues progressively weakens over time.



Historical background:
Due to the rareness of the disease, physicians in the past have associated the disease with other types of muscular dystrophy. It was not until the mid-1960s that Dr. Alan Emery and Dr. Fritz Dreifuss described the specifics conditions of the disease. After the genetic study of a large family that had the disease in Virginia, the two physicians found that the disease had its own characteristics and conditions. Since then, it has been confirmed with other research that the disease can be caused by either autosomal dominant, autosomal recessive, or X-linked mutation in the genome.

Common symptoms:
Early signs and symptoms include contractures that restrict certain joints especially around the elbow, ankles, and neck. The weakness and wasting of muscles in the extremities later slowly progress to the cardiac muscle tissues.

Standard treatments:
There is no effective treatment for the progressive muscle weakness. However, some procedures to help increase the quality of life of the patients involve performing surgeries for contractures, cardiovascular health maintenance, and using respiratory aids. Treatments for the heart complications include taking annual EKG, antiplatelet therapy, antiarrhythmic drug, pacemaker, and sometimes a heart transplant.

Autosomal Dominant Emery-Dreifuss muscular dystrophy:
This type of muscular dystrophy is caused by the heterozygous missense mutation in the Lamina A/C coding gene. Because of the mutation, production of Lamina A/C protein will decrease, leading to the fragility in the nuclear envelope in the cells. So when mechanical stress is applied to the nucleus, the membrane is easily broken and causes cell death in the muscle tissues. The mutation can also induce abnormal chromatin association, which will alter the cell differentiation and proliferation process during its growth.

X-linked Emery-Dreifuss muscular dystrophy: This is the most common type of the disease. It is caused by missense mutation in EMD and FHL1 gene, reducing the number of normal Emerin and FHL1 protein in the cell nuclear membrane. The mutation can also produce wrong protein receptor in the inner nuclear member. Both of these results by the mutation can lead to decrease the binding of Emerin and FHl1 protein to Lamina, and thus a decrease in activation of Lamina proteins in the membrane.

Current research:
Emery-Dreifuss muscular dystrophy is a rare form of muscular dystrophy, but understanding the differences associated specifically with this type of muscular dystrophy need to be distinguished for a more effective treatment. The cure to the disease had not been found yet. However, there are ongoing research to terminate the production of toxic proteins using gene therapy, gene silencing, and cell therapy (Muscular Dystrophy Association).

References:
<span style="font-family: Webdings,sans-serif;">Bonne, G., Leturcq, F., and Yaou, R. (2013). Emery-Dreifuss muscular dystrophy. //GenesReview.// Retrieved from [] <span style="font-family: Webdings,sans-serif;">Genetics Home Reference. (2014). Emery-Dreifuss muscular dystrophy. Retrieved from [] <span style="font-family: Webdings,sans-serif;">Muscular Dystrophy Association. //Emery-Dreifuss Muscular Dystrophy: Research.// Retrieved from http://mda.org/disease/emery-dreifuss-muscular-dystrophy/research