Overview
Duchenne Muscular Dystrophy (DMD) is the most common inherited muscle disease of childhood (~1/3,500-5,000 male births). Dystrophin, which protects muscle against mechanical stress, cannot be produced; the muscle fibre is damaged with every contraction. With standardised multidisciplinary care and new treatments, the natural course has changed considerably.
Genetic Cause
The X-linked DMD gene (the largest in the genome): deletions (~65%), duplications (~10%) and point mutations. If the reading frame is preserved, the milder Becker phenotype is seen. About 1/3 of cases are de novo; in the rest the mother is a carrier → maternal testing is essential, and cardiac follow-up (intermittent echo/MRI in adulthood) is recommended for carrier women.
Clinical Course
- Ages 2-5: Inability to run, frequent falls, needing to hold on when climbing stairs, rising from the floor with the Gowers manoeuvre, calf pseudohypertrophy; speech and learning difficulties may accompany this (brain dystrophin isoforms)
- Ages 6-12: Weakness progresses; walking is typically lost around 10-13 years of age (can be delayed with steroids)
- Adolescence onward: Scoliosis, declining respiratory capacity and cardiomyopathy come to the fore — this is the main focus of modern follow-up
Diagnosis
- The gateway: very high CK (thousands to tens of thousands). Request CK also in unexplained AST/ALT elevation — the classic "liver investigation spiral" is a well-known cause of delayed diagnosis
- Genetic sequence: first MLPA (deletion/duplication) → if negative, sequence analysis; muscle biopsy is now rarely required
- The type and location of the mutation determine treatment eligibility (which exon is suitable for exon skipping?) — keep the report
Treatment and Follow-up
Steroids — the main treatment
- Prednisone/deflazacort is started during the motor plateau period (~4-6 years); it improves walking duration, respiratory and cardiac function, and reduces the risk of scoliosis
- Adverse effect management is a package: weight-height monitoring, vitamin D + calcium, vertebral fracture screening (bisphosphonate when needed), behavioural effects, cataract checks
- Adrenal suppression: A stress dose of steroid is required during severe illness/surgery — this must be written on the emergency card; steroids must never be stopped abruptly
- Vamorolone and givinostat are new options approved with the aim of improving the adverse effect profile
Heart and respiration
- Cardiology: echo/cardiac MRI follow-up; starting an ACE inhibitor/ARB at around 10 years of age (or earlier if there are MRI findings) is the standard approach
- Respiration: regular FVC; when it declines, cough-assist devices and night-time non-invasive ventilation — these are evidence-based steps that extend life expectancy
Surgery-anaesthesia warning
Succinylcholine is contraindicated in DMD; inhaled anaesthetics carry a risk of a rhabdomyolysis-like reaction — the team must be informed before every procedure (a written card).
Physiotherapy-orthopaedics
- Daily stretching (the Achilles tendon!), night splints, standing programmes; after loss of walking, scoliosis monitoring and surgery when needed; an appropriate wheelchair-seating system
Prognosis — An Honest Framework
- With standard care (steroids + cardiac protection + respiratory support) today, life expectancy now extends into the 30s and beyond; DMD adults who go to university and work are no longer the exception
- The main factor determining long-term survival is cardiomyopathy management; "protecting the heart early" is today's strongest asset
- Loss of walking is not an "end" but a stage at which care goals change: independent mobility (power wheelchair), education and social participation continue
- The course in the Becker form is much slower; cardiac follow-up is essential there too
Treatment Pipeline — A Detailed Look
- Exon skipping ASOs (exons 51, 53, 45): In suitable deletions, these produce a shortened dystrophin (weekly IV). The level of dystrophin produced is low; the clinical benefit this provides is a matter of scientific debate — next-generation ASOs with enhanced cell entry (peptide-conjugated) aiming for higher dystrophin levels are in clinical trials
- Microdystrophin gene therapy (delandistrogene): approved in the USA; efficacy data are debated, and following serious liver safety events, conditions of use have been narrowed — eligibility should be assessed only with up-to-date information, at an experienced centre. Second-generation vector/cassette designs are under research
- CRISPR/gene editing: Strong results in animal models for permanent frame correction; dose-delivery safety in humans is being studied
- Additional muscle-protective strategies (anti-fibrotic, myostatin pathway) are being investigated with mixed results
Current picture: Genetic Treatments — Duchenne treatment pipeline.
Daily Life
- Written information for school: arrangements for stairs/physical education, a fall plan, an emergency card
- Weight management (steroids + reduced movement) should be addressed early; dietitian support
- Psychosocial support: for the family after diagnosis, for the young person themselves during adolescence
- Participation in patient registries with mutation information — trial eligibility is screened from there
Downloadable: Duchenne Emergency Action Plan (PDF)
You can download the 3-page emergency action plan prepared for children with Duchenne by Nörogender, under the guidance of Prof. Dr. Burak Tatlı. At the centre of the form are DMD's four emergency pillars: steroid stress dosing (chronic cortisone must never be stopped abruptly; continue intravenously in a vomiting child), the heart (ECG + troponin for chest pain/palpitations; a note that "CK is already high"), anaesthesia (succinylcholine strictly forbidden, avoidance of gas anaesthetics), and a warning about fat embolism after fracture. The identification section has spaces reserved for steroid and cardiac medicines. The third page is a medical information note with dosing boxes, for healthcare professionals.
There is also a Routine Follow-up Calendar (2 pages): a year-by-year table and record chart built around four pillars — steroid adverse effect monitoring, annual cardiac assessment (echo/cardiac MRI + ECG), respiration (FVC-cough-night-time), and bone-scoliosis.
📄 Emergency Action Plan (PDF, 3 pages) — in Turkish 📅 Routine Follow-up Calendar (PDF, 2 pages) — in Turkish
Complete the form together with your doctor; keep one copy at home and one at school, and show it to the team before every surgery/anaesthesia.
