Improving recognition of Duchenne muscular dystrophy: a retrospective case note review

BACKGROUND: Over the last 30 years, there has been little improvement in the age of diagnosis of Duchenne muscular dystrophy (DMD) (mean age of 4.5–4.11 years). AIM: To review the diagnostic process for DMD in boys without a family history in order to identify where delays occur and suggest areas for improvement. DESIGN: A retrospective case note review. SETTING: A tertiary centre for neuromuscular diseases in England. PATIENTS: All boys without family history diagnosed with DMD in the last 10 years (n=20). OUTCOME MEASURES: Mean age at four key steps in the diagnostic pathway of DMD. RESULTS: (1) Age at first reported symptoms of DMD was 32.5 (8–72) months (2.7 years). (2) First engagement of a healthcare professional was at 42.9 (10–90) months. (3) Creatine kinase (CK) levels were checked at 50.1 (14–91) months. (4) Diagnosis of DMD was confirmed at 51.7 (16–91) months (4.3 years). The total delay from parental concern to diagnosis was 19.2 (4–50) months (1.6 years). CONCLUSIONS: Our study shows an improvement in the age of diagnosis of DMD although there continues to be a delay in presentation to a health professional and a delay in obtaining a CK test. To reduce these delays, we propose screening for DMD as part of the Child Health Surveillance Programme, in addition to lowering the threshold for CK testing in primary care by promoting a new DMD mnemonic MUSCLE. An earlier diagnosis of DMD will allow timely access to genetic counselling, standards of care and clinical trials.