Symptoms of Duchenne muscular dystrophy (DMD)
It’s unusual for symptoms to be present from birth. Often signs will appear between 1 and 2 years of age.
Someone with DMD might experience:
- difficulties running, jumping and climbing stairs
- difficulty getting up from the floor
- a waddling gait (walking on their toes with an arched lower back)
- difficulty walking as fast or as far as other children
- a tendency to fall more than other children
- learning and behavioural difficulties
- learning to speak later than usual
Many people with Duchenne use the Gowers’ manoeuvre to stand up by:
- facing the floor
- placing their feet wide apart
- lifting their bottom first
- walking their hands from their knees to their thighs to a standing position
Cause of DMD
- DMD is a type of sex linked (X-linked) muscular dystrophy.
- Males have one X and one Y chromosome (long threadlike structures of DNA). Females have two X chromosomes.
- A sex linked disorder is caused by a mutation in a gene on the X chromosome.
- As males only have one copy of the gene on the X chromosome, they’ll be affected if one of those genes is mutated.
- Because females have 2 copies of the X chromosome, they’re less likely to develop an X-linked condition. This is because the healthy copy of the chromosome can usually compensate for (mask) the mutated version. This means that although females can still be affected by X-linked disorders, the symptoms are likely to be less severe.
Pompe Disease 