Duchenne and Becker muscular dystrophy: implications for at-risk individuals
Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are severe X-linked recessive, degenerative neuromuscular diseases. DMD/BMD are caused by deletions, duplications and point mutations in the DMD gene situated on the X-chromosome. Studies have shown that the risk of being a carrier for DMD/BMD has a psychosocial impact on individuals and affects their requests for DNA testing and their choices regarding reproduction. Very few articles have been published to date and this study is the first South African study to investigate the behaviours of individuals in DMD/BMD families. The study aimed to investigate why individuals attended genetic counselling and who referred them. It also aimed to identify factors that influence at-risk individuals‟ decisions regarding genetic counselling, carrier testing and reproduction. The study was retrospective and data were obtained by reviewing genetic counselling files at the Division of Human Genetics, National Health Laboratory Service and the University of the Witwatersrand. The sample consisted of 79 files of families seen for genetic counselling regarding DMD/BMD from 1995 to 2008. Subjects included the maternal female relatives of affected individuals, who were all of reproductive age (15-49 years); the total number of at-risk individuals identified was 237. Subjects were divided into three groups according to their assigned reproductive risks: low (0-9%), intermediate (10-24%) and high (>25%). The influence of reproductive risk and other identified variables on decisions to attend genetic counselling, have carrier testing and having children were analysed using chi-squared and logistic regression analysis. iii Reproductive risk and relationship to the affected individuals were shown to be significant predictors of individuals‟ decisions. Other factors that contributed significantly to the behaviour of at-risk individuals were ethnicity, age, whether a mutation was de novo and whether an individual had affected children.
MSc (Med), Genetic Counselling, Faculty of Health Sciences, University of the Witwatersrand, 2009
Duchenne muscular dystrophy, Becker muscular dystrophy, genetics, risk