Exciting News: New Gene Identified to Cause Centronuclear Myopathy

Scientists in Paris, in collaboration with researchers from the United States and other European countries, recently identified a second gene that can cause Centronuclear Myopathy (CNM). The new CNM gene, DNM2, is named after its protein product, Dynamin 2. Changes (alterations) in one region of the DNM2 gene cause a specific form of Centronuclear Myopathy with later onset of muscle weakness and Autosomal Dominant inheritance. Alterations in other sections of the DNM2 gene have previously been associated with another unrelated genetic condition known as Charcot Marie Tooth disease.

Every person inherits two copies of most genes, including DNM2. (We generally inherit one copy of each gene from each parent.) DNM2 alterations in patients with CNM are inherited in an autosomal dominant manner; only one copy of a non-working DNM2 gene is necessary to cause the condition. Therefore, a parent with a DNM2 alteration can pass CNM directly to her or his children. Some individuals with autosomal dominant CNM have new (de novo) alterations in the DNM2 gene, which were not found in either parent. This finding suggests that not all individuals with CNM caused by DNM2 alterations will have a family history of the condition.

The discovery of the role of DNM2 in CNM will allow for the improved diagnosis of individuals with Autosomal Dominant CNM, as well as allowing for prenatal diagnosis. In addition, the understanding of DNM2’s role in muscle permits an increased understanding of muscle function, bringing us closer to developing treatments and cures for all congenital myopathies. The discovery was announced in Nature Genetics in November 2005.

The MTM1 gene, which was the first gene to be discovered was originally described in 1996. Some of this information has now been disproven but the description of the gene itself is still relevant.
A new review article entitled
X-Linked Myotubular and Centronuclear Myopathies
was published in July 2005 and provides information about the current status