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Letters Modern genetics

No blind alleys in the clinic

BMJ 2010; 340 doi: (Published 25 May 2010) Cite this as: BMJ 2010;340:c2754
  1. Andrew G L Douglas, academic clinical fellow in clinical genetics1
  1. 1Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton SO15 6YA
  1. andrew.douglas{at}

    In discussing the practical benefits of modern genetics, Le Fanu states that the prevention of monogenic disorders through antenatal screening is limited to thalassaemias and Tay-Sachs disease.1 In fact, when any causative genetic mutation is known in a family, routine antenatal testing through amniocentesis or chorionic villus makes it possible to look for the same mutation in a fetus. In most cases it is therefore technically possible, though of course not always appropriate, to diagnose prenatally any monogenic disorder for which there is a known mutation.

    Furthermore, Le Fanu did not discuss the impact of clinical genetics on patients and their families. Thanks to increasing genetic understanding and the availability of ever improving diagnostic techniques, clinical geneticists can now offer more effective genetic counselling based on better information. This allows patients and their families a more informed choice in how to manage their genetic conditions, whether in the form of prenatal testing in pregnancy or predictive testing for an adult onset disorder such as Huntington’s disease or breast cancer associated with BRCA genes.


    Cite this as: BMJ 2010;340:c2754


    • Competing interests: None declared.


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