Myotonic dystrophy type 1 is caused by mutations in the DMPK gene, while type 2 results from mutations in the CNBP gene. The protein produced from the DMPK gene likely plays a role in communication within cells.
How does someone get myotonic dystrophy?
Both Type 1 and Type 2 myotonic dystrophy are inherited in families in an autosomal dominant pattern. In autosomal dominant inheritance, having one copy of the altered (mutated) gene in each cell will cause the disorder. Usually a person who has myotonic dystrophy also has a one parent who has myotonic dystrophy.Jul 5, 2017
How is DM1 inherited?
Both DM1 and DM2 are inherited in an autosomal dominant pattern, meaning it takes only one flawed allele, one copy carrying the abnormal expansion, to cause symptoms of the disease. If one parent has the disorder, every child of that person has a 50% chance of inheriting the gene flaw that causes it.
What is the life expectancy of someone with myotonic dystrophy?
We found a median survival of 59–60 years for the adult-type myotonic dystrophy. Reardon et al. (1993) found a median survival of 35 years for the congenital type. Thus, patients with the adult-type of myotonic dystrophy have a considerably better prognosis than those with the congenital type.
Is myotonic dystrophy life threatening?
Some people may experience only mild stiffness or cataracts in later life. In the most severe cases, respiratory and cardiac complications can be life-threatening even at an early age. In general, the younger an individual is when symptoms first appear, the more severe symptoms are likely to be.
Can myotonic dystrophy skip a generation?
As myotonic dystrophy is passed from one generation to the next, the disorder generally begins earlier in life and signs and symptoms become more severe.
How fast does myotonic dystrophy progress?
In general, people with myotonic dystrophy type 2 have a better long-term outlook ( prognosis ) than those with type 1. Symptoms are usually relatively mild. While the rate of progression can vary among affected people, symptoms generally progress slowly.
Can myotonic dystrophy be cured?
There is currently no cure or specific treatment for myotonic dystrophy. Ankle supports and leg braces can help when muscle weakness gets worse. There are also medications that can lessen the myotonia. Other symptoms of myotonic dystrophy such as the heart problems, and eye problems (cataracts) can also be treated.Jul 5, 2017
What causes Steinert disease?
Type 1 DM (DM1), long known as Steinert disease, occurs when a gene on chromosome 19 called DMPK contains an abnormally expanded section located close to the regulation region of another gene, SIX5.
Who is most likely to get myotonic dystrophy?
DM is the most common muscular dystrophy among adults of European ancestry. The prevalence of DM is about 10 cases per 100,000 individuals. Among nonwhite populations, DM1 is uncommon or rare.