Carrier screening for Duchenne muscular dystrophy (DMD): why is it important and who is eligible?

Early detection means that women who are carrying the DMD mutation can:

• Be offered genetic counselling, which can inform them about the risks of transmitting the mutated allele in future pregnancies²
• Have the option of prenatal genetic testing²
• Be made aware of alternative reproductive options, such as the use of donor eggs or human assisted reproduction with preimplantation genetic diagnosis (PGD)²
• Undergo regular surveillance for cardiomyopathy from early adulthood⁵
• Receive early cardiac treatment if heart involvement is detected^3,4

Who is eligible for carrier analysis?

Family members of an individual with DMD should receive genetic counselling to establish who is at risk of being a carrier.¹

Carrier genetic testing should be performed in female relatives of a boy or man who has been genetically confirmed to have DMD.¹

Carrier testing may help reduce the transmission of Duchenne muscular dystrophy and improve outcomes for women at risk.^1-4 Click here for the 2018 Duchenne Care Considerations.

Carriers of Duchenne muscular dystrophy (DMD): symptoms & care

Approximately 10% of female carriers show some disease manifestations,^1,2 which include:

Muscle weakness^3-5

Cardiomyopathy^3,4

Central nervous system manifestations⁴

^{Adapted from references 3-5}

The 2018 Duchenne Care Considerations recommend performing cardiac assessment in all female carriers in early adulthood every 3–5 years.³ This should consist of an electrocardiogram and non-invasive imaging. Assessments should be more frequent in those who are symptomatic or imaging-positive.³

Diagnosis of DMD in children takes an average of 2 years from parental concern. Therefore, carrier women may have more children without realising that they carry a DMD mutation.^6-8

Carriers may be at risk of Duchenne muscular dystrophy symptoms.³ Learn about the importance of carrier screening for Duchenne muscular dystrophy here.

How common is Duchenne muscular dystrophy (DMD)?

DMD is an x-linked recessive disorder that primarily affects males.^1,2 While a rare disease, it is the most prevalent of all neuromuscular disorders, affecting 1 out of every 3,600–6000 newborn males worldwide.^2-4

If a female carries the mutation in the dystrophin gene on one of the two X-chromosomes, she may also be affected by DMD. Approximately 10% of female carriers show some disease manifestations, with cardiac involvement a frequent finding.^2,5

Adapted from MDA⁶

Duchenne muscular dystrophy primarily occurs in males, but can affect females in some cases.^1,2 Learn about carriers of Duchenne muscular dystrophy; symptoms and care here.

Genetic counselling offers many benefits for families living with Duchenne muscular dystrophy (DMD)

5 reasons to refer DMD families to a genetic counsellor:^1-3

They provide education about DMD and its therapeutic options

They can coordinate diagnostic genetic testing

They can establish who is at risk of being a carrier and organise carrier genetic testing

They can discuss family planning options

They provide emotional counselling

International Care guidelines recommend that family members of an individual with Duchenne muscular dystrophy should receive genetic counselling to establish who is at risk of being a carrier.