Cousin Marriage: A Problematic Tradition
by Fatma Abdulla
The incidence of cousin marriages (i.e. consanguinity) in the UAE has increased significantly in the last four decades. The paper presents a comprehensive evaluation of the health consequences of consanguineous marriages. In essence, three adverse health outcomes of consanguineous marriages were found. First, cousin marriage has an adverse impact on fertility as cousin marriages lead to male factor infertility and women’s reproductive health issues. Second, offspring of cousin marriages are more likely to have severe genetic defects, which are likely to result in either physical malformations or serious health conditions or chronic illnesses. Third, consanguinity is also associated with mental retardation, mental performance problems and mental health issues. In light of the adverse health outcomes of cousin marriages, the increasing incidence of cousin marriage in the UAE should be understood as a cause for concern. In particular, the paper argues that awareness should be spread about the adverse effects of cousin marriages and cousin marriages should be regulated by the UAE government.
Keywords: consanguinity, fertility issues, public health, genetic defects, mental retardation.
Cousin Marriage: A Problematic Tradition
Over the last few years, the incidence of cousin marriages (scientifically known as consanguineous marriage) has increased significantly in the UAE. Whereas cousin marriages only accounted for a third of the marriages in the 1970s (Al-Gazali et al., 1997), nowadays, it is estimated that almost half of the marriages among Emiratis are between cousins (Thomas, 2018). At first glance, this should not appear to be problematic. After all, cousin marriages are nothing new in the Emirati culture. They have been commonplace in Emirati history and they can even be considered a preferred type of marriage in Emirati culture. In fact, cousin marriages are quite common throughout the Arab World and also in many Muslim nations (Tadmouri et al., 2009). In recent years, however, the phenomenon of consanguineous marriage has come under intense scrutiny due to the association of consanguinity to genetic defects in children. In general, there are two positions in research literature on how consanguinity influences genetic defects in children. The first position is that consanguinity causes genetic defects (Hamamy, 2012; Mete et al., 2017) and hence consanguineous marriages should either be discouraged or proper pre-pregnancy medical procedures should be followed. A relatively new position on the research in genetic effects of consanguinity is that consanguinity provides genetic benefits over non-consanguineous marriages (Bhopal et al., 2013). Since there are conflicting perspectives regarding the effects of consanguinity, there is a need to carry out an objective assessment on the effects of consanguinity. This paper provides a comprehensive evaluation of the health consequences of cousin marriages. It argues that the practice of cousin marriages should be regulated in the UAE because it has negative consequences on fertility and the physical and mental health of the offspring of such marriages.
Cousin Marriage and Infertility Issues
A significant health issue caused by cousin marriage in the UAE is infertility. Infertility refers to the inability to have children despite trying to conceive. The Emirati population in the UAE has witnessed a drastic drop in fertility over the last five decades. Al-Kuttab (2018) illustrates the extent to which fertility has decreased in the UAE. Whereas the fertility rate was 6.9 births per woman in 1971, the fertility rate in 2013 was only 1.5 (Al-Kuttab, 2018). In fact, more than 50% of Emirati women face problems when trying to conceive (“50% of women in UAE,” 2016). This is troublesome for many reasons, one of which is that it prevents the chances of Emiratis becoming a majority in their own country. For Emiratis to become a majority, it is estimated that they would need to have a fertility rate of at least 3.0 and maintain this for the next two decades (Al-Kuttab, 2018). The decrease in fertility rates has been associated with changes in social life due to modernization, such as Emirati males using muscle development supplements and Emirati females spending excessive amounts of time close to their smartphones (Al-Kuttab, 2018). A recent study, however, questions the association of infertility amongst Emiratis to changes in lifestyle (Emirates 24/7, 2016). Instead, the study conducted by an infertility clinic in the UAE finds that cousin marriage might be the most important contributing factor behind low rates of infertility among married cousins. The proposition that cousin marriage can cause fewer births is by no means new and it has been proposed by several researchers over the years.
Cousin Marriages and Male Factor Infertility
There are several reasons for why cousin marriages generally result in reduced fertility. A major reason that cousin marriages reduce fertility is that cousin marriages are a leading cause of male factor infertility. Simply speaking, male factor infertility refers to the situation where infertility in the relationship arises due to the man possessing weak sperms that are not capable of making women pregnant (Inhorn, 2013). Several studies have observed that cousin marriage is positively associated with male factor infertility. One such study specific to the Arab region was conducted by Inhorn et al. (2009). Inhorn et al. studied two hundred fertile and infertile males coming for treatment at two fertility clinics in Beirut, Lebanon. After looking at what factors might have contributed to their infertility, Inhorn et al. found that four-fifths of the infertile men had consanguineous parents. Upon further testing, Inhorn et al. found that the male children of consanguineous parents were much more likely to inherit genes that led to weak sperms than children of non-consanguineous parents. To be exact, Inhorn et al. found that males with consanguineous parents were three times more likely to suffer from infertility issues. The two major issues males with consanguineous parents were likely to face were that either their semen had no sperms or very weak sperms. Similar findings were achieved by Demirtas et al. (2013), in their study on the effects of consanguinity on male fertility in Turkey. Demirtas et al. studied more than 1,300 men in Lebanon and found that offspring of consanguineous parents were 50% more likely to suffer from fertility issues. Demirtas et al. (2013) observed that the most common type of infertility issue faced by offspring of consanguineous parents was azoospermia, which is a condition where the “male semen does not contain any sperm” (p. 54). Azoospermia is not treatable and those individuals who suffer from azoospermia are unlikely to produce any offspring from their own semen.
Any form of male infertility in the UAE can be quite disturbing for men who suffer from it. Inhorn (2013) observes that men who suffer from infertility are very unlikely to pursue treatment for it. This is because the ideal Emirati man is believed to be highly fertile and infertility is generally associated with women. For Emirati men to pursue treatment for infertility is to reject traditional beliefs about masculinity. As masculinity holds a lot of value for Emirati men, they are unlikely to accept that any infertility is their fault and hence they are unlikely to pursue treatment. When they do pursue treatment, men are likely to get depressed. As azoospermia is untreatable, those who suffer from it might even face gender identity issues as they question their own masculinity. We can thus see how cousin marriage can have severe consequences on male fertility and this can subsequently have even more devastating consequences for the mental health and well-being of married men.
Cousin Marriages and Women’s Reproductive Health
The effects of cousin marriage on fertility are not only restricted to men, but cousin marriage also has several negative effects on women’s reproductive functions, which also results in reduced fertility. For instance, a study was conducted at the University Hospital Brussels in Kuwait on infertile women and the study found evidence that even female offspring of consanguineous parents were likely to suffer from infertile conditions ("Significantly higher rate of infertility," 2013). The study compared the conditions of newly married infertile women to newly married fertile women. After comprehensive analysis of infertile women who were children of consanguineous parents, the study found that three-quarters of infertile women with consanguineous parents had limited ovarian reserves. In fact, the lead researcher of the study – Dr. Human Mousavi Fatemi – observed that the ovarian reserves in female offspring of consanguineous parents in their late twenties were equal to what is found in women above the age of forty who are near menopause. Unlike male factor infertility caused by azoospermia, though, the condition of low ovarian reserves is treatable.
Unfortunately, low ovarian reserve is not the only reproductive health issue that is caused by consanguineous marriage in women. A plethora of research in fact shows that pregnancies among consanguineous couples generally are subject to more complications than non-consanguineous couples. For instance, Bokhari et al. (2015) carried out a study on the reproductive health effects of consanguinity in Pakistan. The researchers found that pregnancies of consanguineous couples were almost four times more likely to result in the death of the child within the womb than pregnancies in non-consanguineous couples. The most common reproductive health issue identified by Bokhari et al. was still birth followed by intrauterine death. The researchers did not note what caused this issue. A similar study conducted by Tadmouri et al. (2009) also found that there was “a higher rate of prenatal losses among consanguineous couples” as compared to non-consanguineous couples (p. 22). Tadmouri et al. also reviewed other effects of consanguineous marriage on reproductive health and generally found that the effects were largely negative. Based on the findings, Tadmouri et al. advised that young Arabs who are wanting to get married should consider the scientific aspect of what consequences marrying someone can have. With evidence showing that even women’s fertility is negatively affected by cousin marriage, it seems absurd that cousin marriage in the UAE is not being addressed as a major cause of infertility.
Cousin Marriages, Stress, and Infertility Issues
A final factor in cousin marriages that contributes to infertility is the higher levels of stress and depression in cousin marriages as opposed to non-cousin marriages. In the Arab World, cousin marriages are usually a product of arranged marriages and scarcely are cousin marriages the choosing of the couple itself. Indeed, Tadmouri et al. (2009) confirmed as much in their review of literature on consanguineous marriages in the Arab World. In some situations, cousin marriages can even be forced. For instance, in an analysis of cousin marriages in Turkey, Alper et al. (2004) observe that a third of the cousin marriages are forced as both couples are not particularly interested in getting married. If the marriage is forced, then it is likely that individuals might not have as much attraction for each other and this could result in lack of marital satisfaction. Marital dissatisfaction is likely to be higher among men if they are not sexually attracted to their spouse (Al-Darmaki et al., 2017). Additionally, the basic family unit in the UAE remains to be the extended family and consanguineous couples are more likely to live as part of the extended family in a large household than separately in their own house. This exposes cousin marriages to inter-family conflict and stress arising from such conflict (Al-Darmaki et al., 2017). Moreover, couples are less likely to show affection in an extended family environment and this could affect marital satisfaction (Al-Darmaki et al., 2017). As marital satisfaction is reduced and stress is increased, it can become harder to conceive as it is generally observed that stress reduces fertility (Khayata et al., 2003). Hence, it should be realized that cousin marriages also reduce fertility as they increase stress and dissatisfaction in marriages.
Cousin Marriages and Physical Health Issues
Apart from its effects on fertility, cousin marriages should also be discouraged because offspring of cousin marriages are more likely to have severe genetic defects, which are likely to result in either physical malformations or serious health conditions. Sheridan et al. (2013) carried out a study on the health of more than 13,000 new-borns in Bradford, UK, and evaluated what effect demographics or family conditions might have had on the health of the new-borns. 386 babies in the study were found to suffer from serious genetic defects and Sheridan et al. further found that 31% of the genetic defects could be attributed solely to parental consanguinity. Essentially, cousin marriages increase the likelihood of genetic defects because cousin marriages increase the likelihood that a child would inherit a genetic defect from both parents. According to Hamamy (2012), “first cousins… share 12.5% (1/8) of their gene” (p. 187) and, hence, the possibility that the couple in a cousin marriage shares a genetic defect and transmits it to their offspring is much higher than usual. As consanguinity causes genetic defects to be transmitted to children, it increases the risk of children having autosomal recessive disorders, chromosomal syndromes, reduced immunity, and chronic illnesses such as diabetes and hypertension.
Autosomal Recessive Disorders and Consanguinity
The most problematic health issue caused by cousin marriage is that it increases the possibility of children having autosomal recessive disorders. Autosomal recessive disorders happen when a couple having the same mutated gene both pass the gene on to their offspring and this causes the child to become affected with the gene mutation. As the possibility that both parents have the mutated gene increases in case of cousin marriages, the possibility of children having autosomal recessive disorder also increases. Dr. Justin Thomas (2018), an associate professor of health sciences at Zayed University, observes that “the link between parental consanguinity and the increased incidences of autosomal recessive genetic disorders, thalassemia, for example, is well established” (para. 1). Shawky et al. (2013) further show the extent to which parental consanguinity is responsible for autosomal recessive disorder. In a study conducted over 8,109 persons suffering from genetic issues in Egypt, Shawky et al. found that 80% of autosomal recessive disorders occur because of parental consanguinity.
This is quite concerning as most autosomal recessive disorders are either life-threatening or lead to significantly adverse quality of life. For instance, consider the autosomal recessive disorder called cystic fibrosis. According to Haldeman-Englert and Sather (2018), those affected by cystic fibrosis “produce abnormally thick and sticky mucus that can damage body organs and the produced mucus often interrupts the function of vital organs especially the lungs” (para. 4). The result is that people who have cystic fibrosis are frequently sick with severe infections. They also tend to be quite weak as the mucus produced due to cystic fibrosis also weakens the pancreas and makes it difficult to absorb much needed nutrients (Haldean-Englert & Sather, 2018). In some cases, autosomal recessive disorders can be life-threatening. For instance, most autosomal recessive neuromuscular disorders cause the muscle functioning to deteriorate over time which leads to children initially having problems walking or holding things. With time, muscles that control breathing and eating functions also start to deteriorate and this makes eating and breathing difficult for affected children. In the end, children affected by autosomal recessive neuromuscular disorders die as their respiratory system fails. Children should not be made to undergo such suffering and hence cousin marriages should be avoided when possible.
Cousin Marriages and Reduced Immunity
Apart from causing autosomal recessive disorders, consanguinity also reduces differences in genetic makeup and this makes offspring of cousin marriages more likely to get infected by viral illnesses. Genetic diversity in populations is significantly associated with the susceptibility of a species to get infected by a disease. A large amount of genetic diversity in a population (heterozygosity) is normally associated with reduced risk of susceptibility to infectious diseases. On the contrary, low levels of genetic diversity usually makes a host population highly susceptible to infectious disease. In fact, studies in agriculture have shown that infectious diseases tend to quickly spread in crop populations with the same genetic make-up (King & Lively, 2012). The same has been observed in case of animal populations. Lyon et al. (2009), in their study of hepatitis, tuberculosis and leprosy in Gambia, India and Italy found that lower genetic diversity in humans also increases susceptibility to infectious disease. In particular, the researchers found that lower genetic diversity in humans arises because of consanguineous marriages. The researchers found that children of consanguineous parents were more likely to be infected by hepatitis and tuberculosis due to lower genetic diversity. Based on prior research, Lyon et al. explained that the reason higher genetic diversity reduces disease susceptibility is that infectious diseases themselves need to adapt to different genetic makeups to be effective. However, when genetic diversity exists not only are infectious diseases not allowed to adapt but the genetic diversity also provides with greater ability to fend off the infectious disease.
Cousin Marriages and Chronic Illnesses
Consanguinity is also associated with increasing the possibility of offspring being affected by chronic diseases later in their lives, such as diabetes. Once again this is not difficult to understand given that consanguinity increases disease susceptibility. In fact, research by Bener and Mohammad (2017) in Egypt shows that consanguinity contributes to the occurrence of complex diseases such as diabetes mellitus and heart diseases. In particular, the researchers collected health and family information of 1,228 individuals in Egypt. Bener and Mohammad (2017) found in their research that offspring of consanguineous parents “had a slightly higher risk for diseases such as diabetes mellitus, cancer, heart diseases, asthma, gastro-intestinal disorders, hypertension, and common eye diseases” (p. 315). As cousin marriage generally increases the susceptibility of offspring to genetic defects, infectious diseases and complex diseases, there is no justification of cousin marriages from a health perspective. For a society to be healthy, it is essential that genetic diversity is promoted and for that cousin marriages need to be avoided.
Cousin Marriage and Mental Capabilities
Apart from causing physical health issues and deformities, parental consanguinity also is related to mental retardation, mental performance problems, and mental health issues. In particular, parental consanguinity is recognized as a leading cause of mental retardation and brain defects. For instance, parental consanguinity also increases the likelihood of Down’s syndrome (Shawky et al., 2013). It also increases the possibility of children facing developmental delays or having malformations in their brain structure which can lead to stunted growth or mental capabilities. For instance, Anusha (2012) observes that lissencephaly is a condition often found among offspring of cousin marriages in this condition the brain does not develop properly during pregnancy. When lissencephaly is severe, children usually are unable to live past the age of three and they usually suffer for much of the time they are alive. With time, in severe forms of lissencephaly, the muscles of various parts of the body stop functioning. First, the muscles for limbs and then the muscles for the respiratory system and then for the cardiovascular system. The result is that throughout their short lives, children continue to suffer until they die under painful conditions. Under no circumstances should children be allowed to suffer this much. Lissencephaly is largely an autosomal recessive disorder and hence parental consanguinity is a major cause of lissencephaly. Hence, it is important to reduce cousin marriages by as much as possible.
In recent years, research has also shown that consanguinity has a negative effect on children’s mental health and mental performance. In particular, parental consanguinity is noted to have a negative effect on the intelligence and mental capabilities of the offspring. Abu-Rabia and Maroun (2005), for instance, carried out research looking at the differences in reading abilities between children of consanguineous and non-consanguineous parents. Abu-Rabia and Maroun studied the reading skills of 814 middle-school students and studied word recognition, phonological awareness, phonological decoding and comprehension of students. The researchers found that children of non-consanguineous parents had better reading skills. The authors observed that it is possible that this difference might arise due to consanguineous children having a different brain structure. With regards to the Arab World, Saad et al. (2014) found that children of consanguineous parents have a higher risk of having intellectual disabilities than non-consanguineous parents’ children. Hence, it is clear that children of consanguineous parents simply do not have the same intelligence and mental capabilities as those of non-consanguineous parents. This can have quite adverse effects on the lives of such children. These children are likely to perform poorly in school not because they work any less but because they lack the cognitive ability to perform well. Essentially, consanguineous couples put their children at a disadvantage.
Consanguinity in recent years has also come to be associated with common psychiatric disorders, such as anxiety and depression, and serious mental disorders such as Alzheimer’s and dementia. Bener (2017) carried out a large-scale study in a GCC country on how consanguinity affects the risk of mental illnesses. After carrying out psychiatric tests on more than 1,400 individuals, Bener found that 45% of the population suffered from various mental health illnesses. Almost a third of the sample was consanguineous. Bener found that in the consanguineous sample, the amount of people suffering from mental health issues was almost 70%. In other words, children of consanguineous couples were at higher risk of mental illnesses. The particular mental illnesses faced by consanguineous offspring included “generalized anxiety disorders; social phobia, specific phobia, major depression, and personality disorders” (Bener, 2017, p. 512). Apart from these mental illnesses, consanguinity also increases the risk of severe mental disorders such as Alzheimer’s and dementia. Kaur and Balgir (2005) conducted research on 100 elderly individuals in India who were at-risk of Alzheimer’s. The sample included both consanguineous and non-consanguineous persons. For each person, the extent to which they were at risk of Alzheimer’s was evaluated along with genetic testing for Alzheimer genotypes. Kaur and Balgir observed that APOE genotype is responsible for Alzheimer’s and in this genotype the prevalence of E4 alleles is associated with increased likelihood of Alzheimer’s whereas E2 alleles is said to protect against the risk of Alzheimer’s. However, in their research, Kaur and Balgir found that in consanguineous patients, the E2 alleles did not perform its protective role as intended. Moreover, the consanguineous group in the study had a higher prevalence of E4 alleles. In other words, consanguinity put people at greater risk of Alzheimer’s and dementia.
Based on the discussion so far, it is quite clear that cousin marriage is not at all beneficial for Emirati society. It has significantly adverse consequences. It is causing higher rates of infertility, severe genetic defects, and significant mental health problems in the Emirati population. This is highly undesirable. Instead of allowing cousin marriage to flourish, the UAE government should take note of the increasing trend of cousin marriages in the UAE. The UAE government should educate the entire population on the dangers and issues related to cousin marriage. If individuals still want to marry their cousins, they should be tested before they get married to make sure that their offspring will not have any negative health effects. Such testing is available in the UAE and is known as pre-implantation genetic diagnosis (PGD). If there is a chance that their offspring will have negative health effects, the parents should be recommended to have children through IVF treatments where the harmful genes identified through PGD can be taken out of the sperm and ovaries of the parents. Also, care needs to be taken in considering if the parents of a consanguineous couple were consanguineous themselves as this implies a likelihood of infertility issues which can make conception through even IVF difficult. In this case, it would be better to address the issue even before marriage. The better option would be to avoid such an extent of cousin marriage. While medical solutions should be made available for consanguineous couples, all efforts should be made to discourage cousin marriage as it possesses huge medical risks.
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