Thursday, July 24, 2014
Inherited Disorders and Birth Defects
Rigid Spine syndrome - Muscular dystrophy
My brother has a rare form of muscular dystrophy called Rigid Spine syndrome. I am a female. I have not been diagnosed but I do have some symptoms that are not severe. Overall muscle weakness and lack of muscle mass and rigidity of the spine (I can`t touch my chin to my chest, actually I can barely move my head forward at all). My parents have no symptoms of muscular dystrophy. How genetic is muscular dystrophy and how likely is it that my children will have muscular dystrophy?
The syndrome you are talking about is congenital muscular dystrophy with rigid spine. This form of CMD usually starts before 1 year of age with prominent neck weakness and poor head control. After some initial improvement, children gradually develop (by 3 to 7 years) stiffness or rigidity of the spine. They may also have some contractures of limb muscles. By the teens, the respiratory muscles are affected more than the limb muscle strength is less affected. Intellectual function is normal.
This type of CMD is caused by changes (mutations) in a gene known as the selenoprotein N-1 gene (SEPN1 gene). It is inherited as an autosomal recessive disease - that is, both parents are carriers for the changed (mutated) gene and have a 25% chance of both passing the mutated gene on at the same time and having an affected child. In your family, your brother inherited one mutated gene from your mother and one from your father. Usually, people who are carriers for autosomal recessive diseases (have one normal gene and one changed gene) have no symptoms of the disease. Occasionally however, someone who is a carrier can have mild symptoms. Because you have stiffness in your neck and some muscle weakness, you may be a carrier for the disease.
Because the disease is rare and if you are a carrier, unless you have children with someone who is a relative and thus may have a higher chance of carry the gene that causes CMD, the chance that your children will have rigid spine syndrome is quite low.
I would recommend that you talk to a geneticist or genetic counselor regarding CMD rigid spine syndrome. They would be able to discuss carrier testing for the gene that causes the rigid spine type of CMD and discuss the disorder in detail. You can ask your doctor for a referral or you can locate a genetics clinic near you at the National Society of Genetic Counselors' Resource center - the web site is below.
Also, there is additional information at the Muscular Dystrophy Association website listed below.
Anne Matthews, RN, PhD
Associate Professor of Genetics
School of Medicine
Case Western Reserve University