EVERY year an estimated eight million children six percent of the total births worldwide are born with a serious birth defect of genetic or partially genetic origin," according to the March of Dimes Global Report on Birth Defects.
In this grim bigger picture, Qatar had the dubious distinction of being ranked 16th of the 193 countries surveyed in the report. In Qatar, out of every 1,000 live births, 73 children are born with some sort of a disorder and the majority of these disorders are caused by genetic factors or as a result of genetic-environment interaction.
Environmental factors include but are not limited to rubella, smoking, syphilis, iodine deficiency, etc.
Enumerating the types of birth defects, Dr Khaled Abu-Amero, Laboratory Director, Shafallah Genetics Medical Centre, says, "The common birth defects that we come across are congenital heart defects, neural tube defects, haemoglobin disorders (thalassemia and sickle cell disease), Down syndrome, different mental retardation disorders, various body dysmorphic disorders (dysmorphia) and recently autism came into this picture."
In an exclusive interview to Qatar Today, Dr Abu-Amero spoke about the main reasons for the defective births in the country and the Arab world in general, the preventive measures that parents should take, the importance of premarital testing and counselling and what approach should be taken to prevent such birth defects.
He emphasised that countries low on development and a large part of the Arab world is rife with this problem.
Sudan tops the list, having 82 out of 1,000 live births with birth defects, followed by Saudi Arabia (81.3), Kuwait (74.9), Oman (74.8), and Syria (74.3). "Not surprising that France has the lowest figure, with 39 birth defects out of every 1,000 live births," he says, quoting the report.
Consanguinity: The main reason
"It is not only Qatar that is plagued by this phenomenon. In fact, the whole Arab world is battling with this issue due to the high consanguinity rate in this region. First cousin marriages and the tribal nature of marriages have resulted in a very high rate of genetic defects among children in some Arab countries. In a recent survey published in 2006, the rate of consanguinity in the present Qatari generation is high (54 percent) and the common type of consanguineous marriages was between first cousins.
"Besides consanguinity, the other reasons behind this worrisome phenomenon could also include: poverty in some Arab countries, malnutrition and survival advantage against malaria for carriers of sickle cell and thalassemia genes, high percentage of older mothers and poor maternal and child health care services."
Prevention, the only panacea
"The practical solution to this problem is through prevention, which should be the prime public health concern where these disorders are prevalent.
"Preventive genetics is best achieved through establishment of national databases on the basis of surveys, target the people at risk and prevalent premarital diagnosis, prenatal diagnosis, pre-implantation genetic diagnosis and by genetic counselling.
"These preventive measures must take into account the social, cultural and religious aspects of the Qatari society. The Saudi Government, for instance, has made testing for thalassemia and sickle cell anaemia compulsory."
Stressing the importance of premarital testing for couples embarking on marriage, as well as prenatal testing for couples on their way to parenthood, he says, "These tests are particularly done for diseases, which families from both sides have a history for. In the case of a consanguineous marriage, both families are considered to stem from the same origin and as such must be tested. For instance, premarital testing for cystic fibrosis, will reveal the genetic mutations that couple in question potentially has. If the couple expresses the trait, they are advised to undergo genetic counselling, which will lay down the possibilities of them having a defective child or a child with a disorder. Whatever choice the couple makes, post counselling is, thus, an informed choice."
Whole Genome Profile
On exercising a lifestyle choice, Dr Abu-Amero explains, "Genetic testing is not only for testing genetic disorders.
One could also opt for doing a Whole Genome Profile in order to determine whether a certain individual carries a mutation(s), which predisposes him/her to develop a certain disease, be it Alzeimer's, Parkinson's, diabetes and so on. This will prepare the individual to take preventive measures and minimise damage."
Young couples planning a family should ideally undergo premarital testing and the results of such testing will determine if they are carriers of a certain mutation. In such a case, a genetic counsellor will discuss with them the consequences of this on their unborn child and the options they have in order to avoid having a child with birth defect.
"If the couple decides to marry, then the counsellor will discuss with them other options available such as prenatal genetic testing. If the results of the pre-natal testing indicate that the unborn child is having a genetic disorder, the counsellor will discuss options available to parents. In extreme cases where the genetic disorder is severe and it will have dangerous consequences on the baby or the mother, then the parents have the choice of not going ahead with the birth and this is in consonance with what Islamic Shariah allows."
Another important option for parents who are carriers of certain genetic disorder is Pre-implantation Genetic Diagnosis (PGD). PGD is the process of detecting some genetic diseases by molecular analysis of cells from an early embryo produced by In Vitro Fertilisation (IVF) and to implant only the healthy embryo in the uterus.
He lists the cases in which PGD is useful:
i) mothers with advanced maternal age;
ii) multiple IVF failures; and
iii) recurrent spontaneous miscarriages.
The Shafallah focus
Shafallah has 500 children, 70 percent of whom have disability, caused either by genetic factors or by the interaction between genetic and environmental factors.
"Our main genetic testing addresses autism, syndromic/non-syndromic mental retardation, blindness, deafness, epilepsy and a wide variety of other disorders. The facility at Shafallah is one of the best in this part of the world and we do advanced genetic tests," says Dr Abu Amero. All genetic testing which will be carried out on Shafallah children is optional and will only be carried out after obtaining consent of the parents and after full explanation of the benefits of testing and what it means to them and to their extended family. Genetic testing will involve drawing 5 cc of blood or obtaining a mouth swab with minimal or no risk to participants.
Shafallah aims to help in preventing defective births by offering genetic counselling and by educating would be parents on the choices before them (especially in cases where a family already has had a defective birth), the counsellors help families make informed decisions.
The Shafallah Genetics Centre also plays a crucial role in extending cooperation to the country's health authorities.
He outlines the extensive education programme for clinical geneticists, students of genetic research and the young scientists' programme, which targets high achievers in science in high schools (A-level).
"In addition, we help as much as we can in advanced genetic testing and by way of community education whereby we organise lectures on genetics and how it affects the daily life of the public at large."
What is genetic disorder?
Genetic inheritance is the transfer of genetic material from parents to offspring. Each offspring gains half of their genetic makeup from their father and the other half from their mother. The offspring express the inherited genetic material in the form of their unique hair colour, eye colour, body shape, etc. This genetic material transfer occurs through the human DNA which carries genetic codes and chromosomes.
Normally, humans carry 46 chromosomes. The male carries 46 (XY) and the female carries 46 (XX). The male sperm is divided into two parts one part carries the X chromosome and the other part carries the Y chromosome. During fertilisation and when the sperm carrying the X chromosome penetrates the ova, which carries only the X chromosome, the zygote becomes female.
However, when the sperm carrying the Y chromosome penetrates the ova, the zygote becomes male. If there is any change in the number or the structure of these chromosomes, a potential defect can result in the offspring.
By Aparajita Mukherjee
© Qatar Today 2007
