30 November 2017
Call for improved genetic services in Arab countries
Published online 21 May 2014
An estimate of congenital birth defect rates shows a higher incidence of anomalies among live births in Arab countries compared to those in Europe, North America and Australia. The problem is compounded by a lack of reliable genetic services in all but a handful of Arab countries.
Consanguineous marriage, customary in most Arab communities and intra-familial unions which account for 20-50% of all marriages1, contribute to a higher than normal rate of birth-defect, while a lack of funding for research and health services is another factor.
The prevalence of congenital anomalies in the offspring of first-cousin marriages has been estimated to be 1.7–2.8% higher than the background population risk, mostly attributable to autosomal recessive disorders2. The culture of large families favoured in some places puts more children at risk of rare autosomal recessive conditions. In addition, women continue to reproduce until later in life in most Arab countries, leading to increase in the birth rate of chromosomal trisomies such as Down syndrome3,4.
Congenital disorders or birth defects include all the etiological categories of genetic diseases, such as single-gene disorders like thalassemia, chromosomal conditions such as Down syndrome, and multifactorial disorders exemplified by the common congenital malformations such as neural tube defects, cleft lip and palate and congenital heart diseases, as well as the anomalies caused by in-utero environmental teratogens or micro-nutrient deficiencies.
A global report estimates birth defects to be greater than 69.9/1000 live births in most Arab countries, as opposed to less than 52.1/1000 live births in Europe, North America and Australia5.
Genetic services available in this region are generally referral centres offering genetic counseling and diagnostic facilities. Some countries have initiated newborn screening programmes for congenital hypothyroidism, phenylketonuria and a handful of other disorders as well as premarital screening programmes for carriers of hemoglobinopathies. Few have effective birth defects registries.
In many Arab countries, ultrasound fetal scanning is routinely performed for any woman during her first antenatal visit. While this procedure can identify major congenital malformations and some chromosomal abnormalities, it is usually done without providing any pre-test information to the parents of the possibility of finding an abnormality and with no explanation of the consequences.
Testing of maternal serum markers is offered by some obstetricians, but it is not mandatory. If the results of the test suggest an abnormality, then the couple will have to decide whether to pursue invasive testing and whether they would terminate the pregnancy if their fetus were affected. However, religious and legal conventions regarding selective termination vary across Arab countries. Experienced genetic counsellors who can interpret abnormal findings and estimate risk according to fetal scanning results and biochemical markers are in short supply.
The strategies do not necessarily require sophisticated technical facilities
An alternative such as preimplantation genetic diagnosis is welcomed in Arab countries since it does not force a decision about abortion, but the procedure is in its early stages, has many limitations and is only available at a small number of centres such as in Saudi Arabia6,7.
In the fairly recent past, health authorities, academic medical institutes and the private sector have made progress in introducing selected genetic services in some Arab countries. But in many countries these are patchy, selective and inadequate. Most importantly, they have not been streamlined.
Widespread access to such services is curtailed by scarce resources and trained health professionals in medical genetics. Genetic diagnosis is often difficult, given the potential diversity of the conditions involved.
Aside from improvements to medical services, educational efforts are needed to increase genetic literacy of the general public, and primary healthcare workers should undertake comprehensive courses and campaigns improve counseling skills specifically related to consanguineous marriages8,9.
In many Arab countries, infant mortality rates have markedly declined and consequently, the proportion of deaths due to congenital disorders has risen. In light of greater survival, it is important to address effective care for those born with such disorders.
Arab countries in general have good programmes in reproductive and other primary health services where community genetic services could be feasibly integrated. Moreover, the high rates of haemoglobinopathies and other single-gene disorders in some countries indicate the great potential of establishing cost-effective care and prevention programmes.
To initiate a nationwide health intervention programme,, there are two prerequisites: to identify priorities and establish if the magnitude of the health problem is significant; and to confirm that care and prevention interventions are both feasible and cost-effective.
Reliable epidemiologic and burden of diseases data collection, along with proper analysis of the situation would help policymakers priorities planning and implementing community genetic services at the primary healthcare level.
Data on the current extent and functioning community genetic services, manpower and laboratory facilities in a country should also be available.
It is crucial to convince policymakers that such services are needed and in demand by the public. Funding for such programmes should be made available. Examples of the success of some programmes in reducing the burden of congenital disorders are available from Bahrain, Cyprus, and Iran10,11,12,13 and could prove that interventions are feasible and effective in reducing the burden of congenital disorders on the community.
The strategies do not necessarily require sophisticated technical facilities but are primarily based on development of newborn and carrier screening services while strengthening the education and training of health professionals and increasing public awareness.Data suggests that health systems in many Arab countries are capable of introducing some basic community genetic services into the primary health care programs. Moreover, middle and high income Arab countries could work to develop the standard of diagnostic genetic services in accordance with the molecular revolution and include the current technology used in the diagnosis and management of congenital disorders.
- Tadmouri,G.O. et al. Consanguinity and reproductive health among Arabs. Reprod. Health 6, 17 (2009).
- Hamamy, H. et al. Consanguineous marriages, pearls and perils: Geneva International Consanguinity Workshop Report. Genet. Med. 13, 841-847 (2011).
- Sawardekar,K.P. Profile of major congenital malformations at Nizwa Hospital, Oman: 10-year review. J. Paediatr. Child Health 41, 323-330 (2005).
- Christianson, A., Howson, C. & Modell, B. Global Report on Birth Defects. The Hidden Toll of Dying and Disabled Children. March of Dimes Birth Defects Foundation: White Plains, New York (2006).
- Murthy, S. et al. Incidence of Down syndrome in Dubai, UAE. Med. Princ. Pract. 16 (1): 25-28 (2007).
- Qubbaj, W. et al. First successful application of preimplantation genetic diagnosis and haplotyping for congenital hyperinsulinism. Reprod. Biomed. Online. 22, 72-79 (2011).
- Hellani, A., et al. Successful pregnancies after application of array-comparative genomic hybridization in PGS-aneuploidy screening. Reprod. Biomed. Online. 17, 841-847 (2008).
- Hamamy, H. Community genetic services in Arab countries. Middle East Journal of Medical Genetics 2 (1), 6-10 ( 2013).
- Al-Gazali, L., Hamamy, H., & Al-Arrayad, S. Genetic disorders in the Arab world. BMJ 333, 831-834 (2006).
- Bozkurt,G. Results from the north cyprus thalassemia prevention program. Hemoglobin 31, 257-264 (2007).
- Khorasani, G., Kosaryan, M., Vahidshahi, K., Shakeri, S., & Nasehi, M.M. Results of the national program for prevention of beta-thalassemia major in the Iranian Province of Mazandaran. Hemoglobin 32, 263-271 (2008).
- Samavat, A. & Modell, B. Iranian national thalassaemia screening programme. BMJ 329, 1134-1137 (2004).
- Al-Arrayed, S. & Al-Hajeri, A. Newborn Screening Services in Bahrain between 1985 and 2010. Adv. Hematol. 2012, 903219 (2012).