Duchenne Muscular Dystrophy

(dmd)

Pronounced: dü-ˈshen
Was first described by the French neurologist Guillaume Benjamin Amand Duchenne in the 1860s.
the most common fatal genetic disorder diagnosed in childhood
progressive muscle weakness leads to serious medical problems, particularly issues relating to the heart and lungs.
The average age of diagnosis is 5 years old.
Boys typically require a wheelchair by mid-teens
Boys typically DO NOT SURVIVE their mid-twenties
THERE IS NO CURE

Average age of Diagnosis is 5 years old.
Delayed Gross Motor Skills: rolling over, sitting up, crawling, walking
Different Gait: Toe walking, walking with belly out
Falling often
Large Calves
Needing help getting up from the floor or using arms to “walk” the body to a standing position (Gower’s maneuver)
Fatigue
Delayed Speech
Behavior and Learning difficulties

the Duchenne gene is found on the X-chromosome, therefore it is passed from the mother and primarily affects boys
If a woman has the Duchenne-causing mutation in one of her chromosomes, she is considered a carrier. As a carrier, she likely has no symptoms of the disease, but she has the ability to pass it along to her child.
Duchenne can be passed from parent to child, but approximately 35% of cases occur because of a random spontaneous mutation. In other words, it can affect anyone.
Duchenne is caused by mutations to the dystrophin gene. Most commonly, one or more exons (a portion of the gene) are missing, and the remaining exons don’t fit together properly. There could also be a duplication of one or more exons.
The mRNA shown below comes from the dystrophin gene, and contains 79 exons that are linked together to form the instructions for making dystrophin protein. Researchers have discovered that mutations, or errors, in the dystrophin gene alter the instructions for making dystrophin.