04 October 2010
Balsall Heath Health Centre, BirminghamAppeared in BioNews 578
Other factors, such as marriages within small communities and mutations supported by selection pressure could also influence the high prevalence of such rare mutations. However, the high rate of autosomal recessive disorders in some communities remains an important issue, regardless of its intricate and complex causes. This needs to be addressed, preferably with input from general practitioners.
Although autosomal recessive disorders are caused by inheriting a copy of a faulty gene from each parent, the risk of this occurring is higher in communities where consanguinity is common. The prevalence of consanguinity in some ethnic communities is 50-70 percent over several generations, which - in itself - significantly increases risk.
During pregnancy, fetuses are screened for several factors affecting wellbeing, such as maternal age, social deprivation, rubella and nutrition - particularly folate deficiencies to prevent neural tube defects. Each of these has an associated campaign with opportunities for screening or intervention.
But there are no similar campaigns offered for genetic conditions, apart from sickle cell and Thalassaemia screening. In general, there are few interventions designed to reduce autosomal genetic illness by increasing genetic literacy and improving informed reproductive choice. Besides, ten weeks into a pregnancy is not the time to counsel a future parent about their genetic risk.
Counselling should be undertaken early and in a sensitive and non-judgemental manner by healthcare professionals familiar with the patients, their families and their community.
Silent unaffected carriers have the least support. Affected patients and their families are often seen and counselled by various healthcare professionals, including clinical geneticists. But, for each affected patient, there are a multitude of carriers who often don't have the same support to make informed reproductive choices.
We have to concentrate on these patients in primary care and no one is better positioned to help than the carrier's GP who has an intricate understanding of the family and the dynamics of the patient's community.
Practice genetics registers, such as those for chronic diseases, could be useful for identifying families at risk. This would allow referral of families to the local clinical genetics department where they could be cascade tested to identify other carriers. These carriers can be counselled for genetic risk when appropriate, perhaps pre-martially or pre-conceptually.
The time for action is now. GPs need to improve their genetic literacy so they can get involved in discussing the increase in risk seen in those communities where consanguinity is common. They should become more aware of the risks in their communities and familiarise themselves with resources available to them to tackle them.
Discussions about genetic risk must be done in a non-judgemental and non-political manner to ensure attempts to link this issue with religion, culture and politics does not interfere with the delivery of key, but simple, genetic education and the encouragement of informed reproductive choices among at-risk families and communities.