Causes
Duchenne Muscular Dystrophy, sometimes referred to as DMD, is a genetic disease that is inherited through a defective gene related to dystrophin; a muscular protein that helps to keep muscles intact. Mutation of this gene results in failure to produce any dystrophin, causing rapid muscle deterioration.
The mutated gene is inherited through a faulty X-chromosome. All women have two X-chromosomes and all men have one X-chromosome and one Y-chromosome. If a woman with one mutated X-chromosome has a son, he will have a 50% chance of inheriting the faulty gene, resulting in DMD. In contrast, if the same woman had a daughter, she would have a 50% chance of inheriting the disorder and only being a carrier of the disability. Being a carrier means that you can pass the mutation on through your genes but, for the most part, will not show any symptoms. This is due to the fact that women have two X-chromosomes and, if only one is mutated, the non-mutated X-chromosome can produce enough dystrophin for the female to be healthy. For a woman to show severe symptoms, she must inherit two affected X-chromosomes, which is highly unlikely. Occasionally, carriers can experience minor muscle weakness or cramping. If a father has a mutated X-chromosome, he can only pass it on to his daughter as the disease is only carried on the X-chromosome. It is possible for a family with no history of DMD to have a son with the disease due to the fact that the mutated gene has not been passed on thus far. It is also possible for a new genetic mutation to develop within a mothers’ egg cell, which is impossible to detect with blood tests.
ghr.nlm.nih.gov/condition/duchenne-and-becker-muscular-dystrophy
https://www.mda.org/disease/duchenne-muscular-dystrophy/causes-inheritance
patient.info/health.duchenne-muscular-dystrophy-leaflet
The mutated gene is inherited through a faulty X-chromosome. All women have two X-chromosomes and all men have one X-chromosome and one Y-chromosome. If a woman with one mutated X-chromosome has a son, he will have a 50% chance of inheriting the faulty gene, resulting in DMD. In contrast, if the same woman had a daughter, she would have a 50% chance of inheriting the disorder and only being a carrier of the disability. Being a carrier means that you can pass the mutation on through your genes but, for the most part, will not show any symptoms. This is due to the fact that women have two X-chromosomes and, if only one is mutated, the non-mutated X-chromosome can produce enough dystrophin for the female to be healthy. For a woman to show severe symptoms, she must inherit two affected X-chromosomes, which is highly unlikely. Occasionally, carriers can experience minor muscle weakness or cramping. If a father has a mutated X-chromosome, he can only pass it on to his daughter as the disease is only carried on the X-chromosome. It is possible for a family with no history of DMD to have a son with the disease due to the fact that the mutated gene has not been passed on thus far. It is also possible for a new genetic mutation to develop within a mothers’ egg cell, which is impossible to detect with blood tests.
ghr.nlm.nih.gov/condition/duchenne-and-becker-muscular-dystrophy
https://www.mda.org/disease/duchenne-muscular-dystrophy/causes-inheritance
patient.info/health.duchenne-muscular-dystrophy-leaflet