AbstractDuchenne muscular dystrophy (DMD) is a progressive, lethal X-linked neuromuscular disorder that has an estimated worldwide incidence of ~1:5000 male live births, with the mean age of diagnosis at 5 years of age. The development of bloodspot creatine kinase (CK) enzyme assays in the 1970’s gave the potential for newborn boys to be screened for DMD. Despite the fact that no curative treatment for DMD existed, several screening programmes were piloted/implemented worldwide during the last 40 years, with the aim to reduce diagnostic delay and enable informed reproductive choice.
The Wales newborn screening programme for DMD was implemented in 1990 and was operational for 21 years. A total of 343,170 boys were screened using a bloodspot CK enzyme assay. Screening reduced the diagnostic delay, enabled reproductive choice for parents of affected boys and allowed early intervention with steroids and physiotherapy. This screening programme was the second longest running programme in the world, but was the most comprehensive with respect to follow-up/outcome data. It was necessary to terminate the Wales programme following the withdrawal of the external quality assurance scheme and because of a lack of sustainability of the reagents used in the test.
There is renewed interest in implementing newborn screening for DMD as advances in molecular therapeutics have led to the development of drugs that can decelerate the deterioration in muscle function.
The presentation will discuss the results of this screening program, the issues of using blood spot CK enzyme activity as a first line screening test and the development of an immunoassay for the measurement of the skeletal muscle CK isoform in bloodspots.