[Show abstract][Hide abstract] ABSTRACT: McGowan R, Challoner BR, Ross S, Holloway S, Joss S, Wilcox D, Holden ST, Tolmie J, Longman C. Results of Duchenne muscular dystrophy family screening in practice: leaks rather than cascades?
Duchenne muscular dystrophy (DMD) is a progressive neuromuscular disease caused by mutations in the gene that encodes the protein dystrophin. Approximately 2 of 3 affected boys inherit their mutation from their carrier mother whereupon other female relatives are at risk of carrying the mutation. Female carriers are also at risk of developing cardiomyopathy and regular cardiac screening is recommended. Clinical genetics services offer genetic counselling and carrier tests for consenting relatives of DMD patients known as ‘cascade screening’. We retrospectively analysed data from two genetics centres, West of Scotland and South East Thames where the latter centre operated a computer-held DMD register. Over the period, 1971–2008, a total of 843 potential carriers, in 195 West of Scotland families, were tested: 16% of 1st degree relatives and 48% of 2nd degree and more distant relatives were not tested. In South East Thames, a total of 1223 potential carriers in 349 families were tested: 49% of 1st degree and 65% of 2nd degree and more distant relatives were not tested. These data are similar to Becker muscular dystrophy/DMD carrier screening results recently reported from the Netherlands. Retrospective results from three countries indicate that despite efforts to offer extended cascade screening, significant numbers of potential carriers of DMD remain unaware of their reproductive and health risks.
[Show abstract][Hide abstract] ABSTRACT: Excessive daytime sleepiness (EDS), of very similar pattern to that seen in narcolepsy syndrome, is extremely common in myotonic dystrophy type 1 (DM1). In a significant minority it has a profound disabling effect on employment, social functioning and activities of daily living. Limited published studies have shown inconsistent results from use of the psychostimulant drug modafinil. A recent European Medicines Agency (EMA) review concluded that on current evidence regarding safety and efficacy, modafinil's use should be restricted to the treatment of narcolepsy. In other conditions (although DM1 was not specifically considered) it was concluded that there was insufficient evidence of benefit to outweigh potentially serious side-effects, including severe skin reactions and cardiac arrhythmia. Clinicians with extensive experience in the management of DM1 have found modafinil to be extremely effective in appropriately selected patients with a very low incidence of serious side-effects. Given the recent EMA review, patients have expressed concern about the potential restriction of the use of modafinil in DM1. This brief review is an audit of the experience of a large group of patients and their clinicians concerning EDS and DM1 and concludes that despite the limited literature there is strong evidence to support the use of modafinil in carefully selected patients.