SELECTED STUDIES


 Premarital Screening Program for Beta-Thalassemia in Jordan

 

By Hanan Hamamy and Sana Al-Hait

 

To initiate a nationwide intervention program for the control of any health problem, there are two main prerequisites. The first is to identify priorities through evidence that the magnitude of a certain health problem is significant, and, the second is that control interventions are both feasible and cost-effective on a community basis. The strategies adopted to achieve these objectives should be carefully selected to match the unique demographic, cultural and religious characteristics of the population.

Available evidence suggests that congenital and genetic disorders are responsible for a major proportion of infant mortality, morbidity and handicap in Arab countries (1-4) The population in the Region is characterized by large family size, advanced maternal and paternal age and high level of inbreeding with consanguinity rates in the range of 25-60% (1,2,5) Certain disorders are common throughout the Arab world such as haemoglobinopathies, G6PD deficiency, different congenital malformations caused by recessive genes and several metabolic disorders (1,2). In view of the good coverage of primary health care system in most Arab countries, community genetic services that include screening programs could be markedly strengthened by the efficient training and education of primary health care personnel (2,4)

Community genetic prevention programs involve a multitude of different approaches with the ultimate goals of minimizing the birth of affected children and better management of patients. The basic pillars that can be adopted for the control and prevention of genetic and congenital diseases on a community level are summarized in figure (1). An important prevention programme that can be adopted in Arab countries is the premarital screening programs to detect carriers of common autosomal recessive diseases and provide them with information that helps them in deciding their marriage and reproductive options.

Beta thalassemia is an autosomal recessive blood disorder with a carrier prevalence rate of around 4% in Jordan ( 6-9). Slight variations in the prevalence rates have been seen in different areas in Jordan. This carrier rate means that the birth incidence for beta thalassemia is about 1 in 2500 livebirths. The number of births in Jordan is around 200,000 births annually which would add around 80 new cases of beta thalassemia every year if no prevention programme is implemented. The expense for management of new cases of beta thalassemia each year plus the number of thalassemic patients already present in the population adds a considerable annual cost for the government.  Premarital screening for beta thalassemia carriers with provision of genetic counselling and public education is considered one of the feasible and effective preventive strategies for minimizing the birth rate of beta thalassemia in Jordan.

Carriers can be detected using routine blood tests, and results are, in general, as precise as DNA diagnosis. When screening is performed as recommended, over 96% of couples carrying a haemoglobin disorder can be detected and informed of their risk and options before they have children ( 10)

Education is an integral part of any community health program. Organized information, education and communication need to be addressed to the population in general through different channels that include school curricula, primary health care clinics and messages through the media. The latter should be scientific and properly formulated, since inaccurate messages could do more harm than good and would eventually interfere with the successful implementation of the program.  Education of health care providers is the other important pillar that needs to be implemented before initiating the screening programme.

 Figure (1): Basic Pillars for the prevention and care of genetic and congenital disorders on community level

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Premarital beta thalassemia carrier screening programmes

Community-based thalassaemia control programmes combining the best possible patient care with prevention through community information, carrier screening, and genetic counselling have proved highly acceptable in a wide range of cultural settings and have led to a marked fall in the number of children born with this disorder. The objective of screening is to offer couples who are at risk information and choice (10).

Community programs for premarital screening to detect beta thalassemia carriers have been initiated in a number of countries including Cyprus, Iran and some Arab countries such as Saudi Arabia, Bahrain, U.A.E. and Tunisia (4).

In Cyprus The carrier rate for beta thalassemia is one of the highest reported, at about 15%. Cyprus was the first country to introduce a successful prevention program in the early seventies , based on pre-marital screening, genetic counselling and offering prenatal fetal diagnosis for beta thalassemia if both couple are carriers. The birth rate of beta thalassemia in Cyprus has decreased to less than 5 cases per year from an expected rate of 70-80 cases (11).

The Iran program started with premarital screening for carriers and was later reinforced with the option of prenatal genetic diagnosis. Amendment of the law in 2001 to allow the option of selective termination of pregnancy up to15 week gestation for thalassemia resulted in a 70% reduction in the expected annual birth rate of affected infants (12).

Premarital beta thalassemia carrier screening program in Jordan

There is an excellent coverage of primary health care facilities throughout all Jordan which would facilitate the integration of community genetic programs into the existing health care without the need for separate vertical programs.

A mandatory premarital screening program for beta thalassemia was initiated in Jordan in June 2004. The program undertakes screening by estimation of Mean Red Cell Corpuscular volume (MCV) for any couple contemplating marriage. The report given to the couple after they undergo the screening test does not include the results of the test so as to assure confidentiality for the couple. If both couple prove to have MCV levels that point to the possibility that they are both carriers, they are then referred for a more diagnostic testing which involves haemoglobin electrophoresis and estimation of hemoglobib A2 level. If both couple have results pointing to carrier status for beta thalassemia, they are referred to a specialist genetic counsellor before giving them the report that is required to certify their marriage. Following genetic counselling, they will have to decide on their future plans and reproductive options without any interference from health personnel so as to assure autonomy of decision (Figure 2). Data on numbers of both couple carriers and their marriage and reproductive options is currently being collected by the National Registry of the Premarital Screening for Thalassaemia at the Section for Prevention of Genetic and Congenital Disorders – Directorate of Disease Control and Prevention, Ministry of Health (MOH) in Jordan. The National Committee for Genetic Diseases established in June 2005 at the MOH is responsible for the evaluation of the thalassemia screening.

A program for training of primary health care workers in Jordan was proposed at the joint MOH/WHO workshop to define the national strategies for the prevention of genetic and congenital disorders held in Amman in 2005. The program entails offering three candidates from each of the 53 comprehensive health centers in Jordan a course of about one month training and education in basic genetic principles and applications. Groups of 25 trainees could participate in each course. Within 6 months to one year all 150 persons would be trained and capable of offering preconception, prescreening and premarital counseling, with referral of at-risk couples to specialized genetic clinics. The first course was implemented in August 2006 at the National Center for Diabetes, Endocrinology and Genetics in Amman, Jordan.

Conclusion:

Although genetic services in Jordan are still scarce, and do not cover all the country due to the major impediments of paucity of resources and trained health professionals in the area of medical genetics, the demographic data suggest that the health system in Jordan is capable of introducing preventive community genetic services into the primary health care system through comprehensive and cost-effective programs such as the premarital screening for thalassemia carriers  (13).

Figure 2: Beta -thalassemia premarital screening programme in Jordan

References:

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Prof. Hanan Hamamy, MD, is a consultant medical geneticist at The National Centre for Diabetes, Endocrinology and Genetics, Amman, Jordan. She is one of the distinguished students of Prof. Alan EH Emery with a plethora of scientific publications. Her email is: hananhamamy@yahoo.com.

Dr. Sana' A. S. Al-Hait, MD is head of Section for Prevention of Genetic and Congenital Disorders at the Directorate for Disease Control and Prevention, Ministry of Health, Jordan. She is the founder of the first genetic counselling clinic in Jordan and the Jordanian Society for Phenylketonuria. She is also the director and organiser of the Premarital Screening Programme for Thalassaemia and the Neonatal Screening Programme.


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