DO NOT WAIT
If you see two or more red flags, refer your patient to a neuromuscular specialist. Get more information
here
WHAT IS DUCHENNE MUSCULAR DYSTROPHY (DMD)?
Duchenne is a rare genetic disorder that affects around 1 in 3,600–6,000 boys.1–4
Click 
in the list below to find out more.
- Duchenne is a severe, progressive muscle-wasting disease1,4–6
- Duchenne primarily occurs in males, but can affect females in some cases2,5
- Duchenne is caused by mutations in the dystrophin gene1,5
- Deletion, duplication, nonsense and other small mutations can cause Duchenne7–9
- With no functional dystrophin, muscle cells degenerate10
1 Like 
THE SIGNS OF DUCHENNE CAN BE DIFFICULT TO DETECT11
This, combined with the rarity of the disease and non-specific early symptoms, means that diagnosis can be delayed by an average of 2 years.4,11,14
Reducing diagnostic delay is important, because early detection can mean:
- Early interventions, which may slow the course of the disease and extend survival4,5,15
- Enrolment in research-based registries and clinical trials4
- Opportunities for genetic counselling and family planning4,5
Like
WHEN TO SUSPECT DUCHENNE5
Positive family history
+
suspicion of abnormal muscle function
Developmental delay, such as not walking by 16–18 months, Gowers’ sign or toe walking
Unexplained increase in transaminases
Unsure of how to recognise developmental delay or abnormal muscle function?
Use the red flag checklist
Adapted from Birnkrant DJ, et al. 20185
PLEASE LISTEN TO CAREGIVER CONCERNS
Caregivers who are worried about their child's development are correct more than 80% of the time*16
*Refers to identification of developmental and behavioural problems
Like
WHAT TO DO IF YOU SUSPECT DUCHENNE
SCREEN, THEN REFER TO SPECIALIST CARE
Order a creatine kinase (CK) blood test
This is a simple and rapid way to screen for elevated creatine kinase (CK) levels – which reflect muscle damage4,17
Refer to a neuromuscular specialist
A genetic diagnosis is required to confirm Duchenne and identify the specific mutation causing the disease5
1 Like
PROMPT REFERRAL IS VITAL TO GIVE YOUR PATIENTS THE BEST CHANCE OF BETTER OUTCOMES4,5
A neuromuscular specialist can then:5
Test creatine kinase (CK) levels5
CK is an enzyme found in skeletal muscle and other tissues. Elevated CK levels reflect muscle damage27
Identify the child’s exact mutation5
Genetic testing can identify the mutation and confirm the diagnosis5
Define best management options5
Timely treatment may help delay disease progression5
Like This information is for EU Healthcare Professionals only and not intended for UK nor Ireland Healthcare Professionals. By clicking OK you are confirming that you are a Healthcare Professional based in the EU
If you are not a Healthcare Professional, visit Duchenne and You for more information on signs and symptoms and support following a Duchenne diagnosis.
Duchenne is a severe, progressive muscle-wasting disease1,4–6
Children with Duchenne suffer with progressive muscle deterioration and an ongoing decline in physical function.1,4–6
Muscle weakness becomes apparent in early childhood, and, on average, patients require a wheelchair by the early teenage years.1,4
Ultimately, respiratory and cardiac failure lead to an early death.4,5
Adapted from Birnkrant et al. 2018 part 1, Bushby et al. 2010; Goemans et al. 2014; Sussman 2002 and van Ruiten et al. 20141,2,4,5,18
Duchenne primarily occurs in males, but can affect females in some cases2,5
Duchenne is caused by mutations in the dystrophin gene1,5
Mutations in the dystrophin gene lead to the absence of, or defects in, dystrophin – an important component of the muscle cell membrane.1,5
Adapted from Muscular Dystrophy Association20
Dystrophin acts as a shock absorber in muscle21
It helps prevent damage by providing stability and structure to the muscle fibre and membrane when muscles contract.10,21
This allows muscle cells to return to their initial state after stress.21
Deletion, duplication, nonsense and other small mutations can cause Duchenne7–9
The dystrophin gene is located on the X chromosome and is the largest gene in the human genome.7 This may make it more susceptible to mutations.22
Adapted from Nowak et al. 2004 and Bladen et al. 20157,23
So far, more than 7,000 individual mutations in the dystrophin gene have been identified.7
Dystrophin gene mutations
Adapted from Bladen et al. 2015, Pichavant et al. 2011 and Kalman et al. 20117–9
Why mutation type matters
It is important to know each patient’s specific mutation, because targeted therapies are being investigated.5,9
Large mutations can be detected using multiplex ligation-dependent probe amplification (MLPA). Small deletions, such as nonsense mutations, require gene sequencing.9
With no functional dystrophin, muscle cells degenerate10
Gradually, muscle is replaced with fat and fibrous connective tissue.10,24,25
T1 weighted magnetic resonance images of thigh muscle as DMD progresses over time24
Adapted from Sweeney 201424
Elevated CK usually means muscle damage27
CK is an enzyme found in skeletal muscle as well as in the heart, brain and other tissues. Increased amounts of CK are released into the blood when there is muscle damage.27
You should order a CK test if a patient has:5
- Unexplained elevated transaminases (AST and ALT)
- A family history of Duchenne and suspected abnormal muscle function
- Developmental delay, such as not walking by 16–18 months, Gowers’ sign or toe walking
WHAT THE RESULTS MEAN5,28
*Elevated CK levels of approximately ≥500 U/L, even if symptomatic, require further assessment and should be followed up.28 CK levels >2000 U/L should prompt further investigation for DMD.28
Refer all patients with elevated CK or missed motor milestones27,28
All patients who have elevated CK levels should be immediately referred to a neuromuscular specialist.27,28
Normal or mildly elevated CK does not rule out neuromuscular disease. If a patient has missed motor milestones, they should also be referred to a neuromuscular specialist.27
- A prompt referral for diagnosis is vital to give your patients the best chance of better clinical outcomes4,5
- Timely interventions may help delay disease progression4,5,29,30
‘Red flags' checklist
This tool provides a comprehensive checklist to help identify early signs or symptoms of neuromuscular disease.
0–4 months
- Cannot hold head up when on tummy at 2 months1,2
- Not rolling over by 4 months1
- Not making sounds by 4 months2
6–9 months
- Not reaching for objects by 6 months1
- Cannot sit without support at 6–9 months1–3
- Not crawling by 9 months1
- Not taking weight on legs while supported2
- Cannot pick up small objects at 9 months1
- Not making vowel sounds at 6 months (‘ah’, ‘eh’, ‘oh’), does not babble at 9 months2
12–18 months
- Not walking by 16–18 months3,4
- Does not perform play activities such as building with blocks by 18 months1
- Difficulty in gripping, for example, not holding or scribbling with crayons by 18 months1
- Not speaking first word by 12 months2
- Does not have at least 6 words by 18 months2
2–3 years
- Not jumping1
- Cannot climb stairs (alternate feet)1,2
- Cannot run, or runs with difficulty2,3
- Cannot climb on and off furniture1
- Difficulty making or copying a straight line or circle1
- Not speaking in sentences by 3 years2
Other early signs and symptoms may include:4,5
- Gowers’ sign (pushing on floor and ‘climbing’ on legs to achieve a standing position)
- Waddling gait
- Enlarged calves
- Inability to keep up with peers
Adapted from references 1–5.
References: 1. Noritz GH, et al. Pediatrics. 2013;131:e2016–e2027. 2. CDC developmental milestones. Available at: https://www.cdc.gov/ncbddd/actearly/milestones/index.html. [accessed April 2019].
3. Lurio JG, et al. Am Fam Physician. 2015;91:38–44. 4. Birnkrant DJ, et al. Lancet Neurol. 2018;17:251–267 [Part 1]. 5. Ciafaloni E, et al. J Pediatr. 2009;155:380–385.
Take
action
action
PLEASE GIVE US YOUR FEEDBACK
Please ensure all questions are answered before submitting
When providing your feedback, no personal information will be collected, linked or shared with other parties, websites or social media platforms.
Thank you for submitting your response!