title: Results of Duchenne muscular dystrophy family screening in practice: leaks rather than cascades?
abstract: 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.
authors.affiliation: North Scotland Regional Genetics Service, Clinical Genetics Centre, Ashgrove House, Foresterhill, Aberdeen, UK. ruthmcgowan@nhs.net
authors.forename: Ruth
authors.initials: R
authors.lastname: McGowan
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Challoner
authors.forename: Sarah
authors.initials: S
authors.lastname: Ross
authors.forename: Susan
authors.initials: S
authors.lastname: Holloway
authors.forename: Shelagh
authors.initials: S
authors.lastname: Joss
authors.forename: Douglas
authors.initials: D
authors.lastname: Wilcox
authors.forename: Simon T
authors.initials: ST
authors.lastname: Holden
authors.forename: John
authors.initials: J
authors.lastname: Tolmie
authors.forename: Cheryl
authors.initials: C
authors.lastname: Longman
mesh_terms: D000328:Adult; D016189:Dystrophin / Q000235:genetics; D005260:Female; D006580:Genetic Carrier Screening / Q000379:methods*; D005817:Genetic Counseling; D005820:Genetic Testing; D006801:Humans; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics*; D012042:Registries; D012189:Retrospective Studies; D006113:United Kingdom
chemical_list: D016189:Dystrophin