Consanguine marriage

{{sex}}
'''Consanguineous''' marriage is a union between couples who are related as second cousins or closer.<ref name=Model>{{cite journal|title=[https://doi.org/10.1038/nrg754 Science and society: genetic counselling and customary consanguineous marriage]|authors=Model, Darr|journal=Nature Reviews Genetics|year=2002}}</ref>

==Prevalence==

[[File:Global prevalence of consanguinity.svg|thumb|300px|Prevalence of marriages up to and including distance of second-degree cousin in 2012.<ref>{{cite journal|title=[https://dx.doi.org/10.1007%2Fs12687-011-0072-y Consanguineous marriages: Preconception consultation in primary health care settings]|author=Hamamy|journal=Journal of Community Genetics|year=2012}}</ref>]]

===Pakistan===
In [[Pakistan]], consanguineous marriage is reported to be higher than 60% of the population in 2014.<ref>{{cite journal|title=[https://doi.org/10.1017/S0021932013000552 Civil unrest and the current profile of consanguineous marriage in Khyber Pakhtunkhwa province, Pakistan]|authors=Sthanadar, Bittles, Zahid|journal=Journal of Biosocial Science|year=2014}}</ref> Also, [[BBC]] reports that an estimate of at least 55% of [[British]] Pakistanis are married to first cousins, and that British Pakistanis are 13 times more likely to have children with genetic disorders than the general population. They account for just over 3% of all births but have just under a third of all British children with such illnesses.<ref>{{cite news|title=[http://news.bbc.co.uk/2/hi/programmes/newsnight/4442010.stm The risks of cousin marriage]|work=BBC|year=2005}}</ref>

===Afghanistan===

In [[Afghanistan]], the proportion of consanguineous marriages is estimated to be 46.2%, ranging from 38.2% in Kabul province to 51.2% in Bamyan province.<ref>{{cite journal|title=[https://doi.org/10.1017/S0021932011000253 Consanguineous marriages in Afghanistan]|authors=Saify, Saadat|journal=Journal of Biosocial Science|year=2012}}</ref>

===Sudan===

In [[Sudan]], the overall percentage of consanguinity range is estimated to be more than 44%.<ref name=Tadmouri>{{cite journal|title=[https://dx.doi.org/10.1186%2F1742-4755-6-17 Consanguinity and reproductive health among Arabs]|authors=Tadmouri et al.|journal=Reproductive Health|year=2009}}</ref> By country, Sudan has the highest level of birth defects.<ref>[https://www.marchofdimes.org/global-report-on-birth-defects-the-hidden-toll-of-dying-and-disabled-children-full-report.pdf Global Report on Birth Defects: The Hidden Toll of Dying and Disabled Children] by Arnold Christianson et al. (2006) ''March of Dimes'', page 3.</ref>

===Saudi Arabia===

[[Saudi Arabia]] reportedly has the highest rate of consanguine marriages in the world with 56% of all marriages consanguine and 33.6% between first cousins.<ref name=El-Mouzan>{{cite journal|title=[https://www.ncbi.nlm.nih.gov/pubmed/18060221/ Regional variations in the prevalence of consanguinity in Saudi Arabia]|au===Italy===
thors=El-Mouzan et al.|journal=Saudi Medical Journal|year=2007}}</ref>

===Italy===

While [[Italy]] as a whole has low rates of consanguine marriages, the late [[Genetics|geneticist]] Luigi Luca Cavalli-Sforza published detailed work, based on both blood typing and parish records, showing relatively high rates of consanguinity on Sardinia and Sicily, and locally in remote pockets of mainland Italy.<ref>Luigi Luca Cavalli-Sforza, Antonio Moroni, and Gianna Zei. ''Consanguinity, Inbreeding, and Genetic Drift in Italy''. Princeton University Press, 2004.</ref>

===Egypt===

A 2013 study cited high rates of single-gene diseases in the Eastern Mediterranean due to cultural practices.<ref>Rabah M.Shawky, Solaf M. Elsayed, Mouchira E.Zaki, et al. "Consanguinity and its relevance to clinical genetics", ''Egyptian Journal of Medical Human Genetics''
Volume 14, Issue 2, April 2013, Pages 157-164. https://www.sciencedirect.com/science/article/pii/S1110863013000037. Accessed May 14, 2019.</ref>

==Reasons==

===Arranged marriages===

Consanguine marriages are often the consequence of arranged marriages. For example, in [[Pakistan]] and [[Bangladesh]], marriages are typically arranged by relatives and there is a strong preference for consanguineous marriage.<ref name=Mobarak>{{cite journal|title=[https://doi.org/10.1017/S0021932018000275 Estimating the health and socioeconomic effects of cousin marriage in South Asia]|authors=Mobarak et al.|journal=Journal of Biosocial Science|year=2019}}</ref>

===Economy===
It has been suggested that consanguinity may be a relatively cheaper way for families to deal with the problem of dowry costs in rural marriage markets, that is, more stringent credit constraints and lower wealth levels will lead to lower dowry payments and a higher prevalence of consanguineous marriages.<ref>{{cite journal|title=[https://doi.org/10.1162/REST_a_00279 The Economics of Consanguineous Marriages]|authors=Do, Iyer, Joshi|journal=The Review of Economics and Statistics|year=2013}}</ref>

===Education===
Female [[education]] may affect consanguineous marriage in at least two ways. Better-educated women demand more freedom in choosing a marriage partner (female empowerment [[hypothesis]]), and going to school prevents women from fulfilling spousal obligations, especially since consanguineous marriages tend to be contracted at a relatively early age (role incompatibility hypothesis).<ref name=Schellekens>{{cite journal|title=[https://doi.org/10.4054/DemRes.2017.37.61 The decline in consanguineous marriage among Muslims in Israel: The role of education]|authors=Schellekens, Kenan, Hleihel|journal=Demographic Research|year=2012}}</ref> According to a 2017 study on [[Muslims]] in [[Israel]], the rise in the age of leaving school explains about a third of 60%-decline of consanguineous marriage between 1975-1979 and 2005-2010.<ref name=Schellekens/> Similarly, a 2013 study on consanguineous marriage in [[India]] concluded that a larger proportion of less educated women (35%) are married to their blood relations compared to women with higher education (11%).<ref name=Doshi>{{cite journal|title=[https://doi.org/10.1108/IJSSP-11-2012-0103 Consanguineous marriages and their effects on pregnancy outcomes in India]|authors=Shrikant Kuntla Srinivas Goli T.V. Sekher Riddhi Doshi|journal=International Journal of Sociology and Social Policy|year=2013}}</ref>

Education may also reduce consanguine marriages by raising awareness about the health risks of consanguinity. A 2015 study on Saudi Arabians found that the odds of a positive attitude towards consanguinity were 50% less in respondents who received health information on consanguinity compared to those who had not received health information about consanguinity.<ref>{{cite journal|title=[https://dx.doi.org/10.5339%2Fqmj.2015.12 Attitude of Saudi Arabian adults towards consanguineous marriage]|authors=Alharbi et al.|journal=Qatar Medical Journal|year=2015}}</ref>

==Religious views==
===Christianity===
In the [[Bible]] there are many examples of consanguine marriages. After his father [[Isaac]] recommended him to do so ({{bible|Genesis|28|2}}), [[Jacob]] married his cousin Rachel ({{bible|Genesis|29|1}}). Later, Jacob also married his other cousin Leah ({{bible|Genesis|29|1}}).

In [[Catholicism]], marriage is invalid between persons related by consanguinity in all degrees of the direct line and that in the collateral line, marriage is invalid up to and including the fourth degree. In particular, first cousins cannot marry in the Catholic Church. However, this last rule is seen more as an "ecclesiastical law" instead of a "divine law", and a special dispensation permits two first cousins to marry validly in the Catholic Church.<ref>{{cite web|title=[https://catholicexchange.com/can-cousins-marry-in-the-church Can Cousins Marry in the Church?]|work=Catholic Exchange}}</ref><!-- better sources? -->

===Islam===
Consanguineous marriage is widely favoured in a large majority of the world's [[Islam|Islamic]] populations.<ref name=Bittles>{{cite journal|title=[https://www.ncbi.nlm.nih.gov/pubmed/10768421 An analysis of consanguineous marriage in the Muslim population of India at regional and state levels]|authors=Bittles, Hussain|journal=Annals of Human Biology|year=2000}}</ref> In particular, many [[Arab]] countries display some of the highest rates of consanguineous marriages in the world ranging around 20-50% of all marriages, and specifically favoring first cousin marriages with average rates of about 20-30%.<ref name=Tadmouri>{{cite journal|title=[https://dx.doi.org/10.1186%2F1742-4755-6-17 Consanguinity and reproductive health among Arabs]|authors=Tadmouri et al.|journal=Reproductive Health|year=2009}}</ref> In Islam marriages between first cousins are not forbidden.<ref>Islam Online; Muzammil H. Siddiqi, [https://archive.islamonline.net/?p=5223 Islamic View on Marrying Cousins]. ([http://archive.is/WqExm archive snapshot])</ref> Two additional factors specifically apply in Islamic society: the belief that in contracting a first cousin marriage of the type father's brother's daughter, the marriage partners benefit from the comparability in status of their respective fathers, and the fact that two of the wives chosen by [[Muhammad]] were biological relatives, and he also married his daughter Fatima to Ali, who was his ward, with the son of his paternal uncle.<ref>{{cite journal|title=[https://doi.org/10.2307/2137601 The Role and Significance of Consanguinity as a Demographic Variable]|author=Bittles|journal=Population and Development Review|year=1994}}</ref>

===Judaism===
While [[Leviticus]] lists a number of prohibited sexual relationships, first-cousin marriages and beyond are not among them. Until the 20th century, cousin marriages were common among Jewish people.<ref>[https://web.archive.org/web/20190505135755/http://www.jewishencyclopedia.com/articles/4611-consanguinity-among-jews Cyrus Adler and Joseph Jacobs, "Consanguinity among Jews," ''Jewish Encyclopedia'' (1906). Accessed Sep. 6, 2019.]</ref>

==Health consequences==

Consanguineous marriage increases a couple's chance of both carrying the same
recessive disease variant and affecting their children. The effect is particularly marked for rare disorders, because a carrier is unlikely to find a partner who carries the same disorder unless they are related. Consequently, in communities in which consanguineous marriage is common, there is an increased birth prevalence of many rare recessive conditions, and a significant increase in the total birth prevalence of congenital and genetic disorders.<ref name=Model/>

In populations with a high rate of consanguinity, there is a significant increase in the prevalence of common adult diseases like cancer, mental disorders, heart diseases, gastro-intestinal disorders, hypertension and hearing deficit.<ref>{{cite journal|title=[https://doi.org/10.1159/000102147 Consanguineous marriages and their effects on common adult diseases: studies from an endogamous population]|authors=Bener, Hussain, Teebi|journal=Medical Principles and Practice|year=2007}}</ref>

A 2018 study on 363.960 individuals born in Northern Ireland shows that being a child of consanguineous parents is associated with having an increased likelihood of psychotropic medication use in adulthood. Precisely, children of first-cousin consanguineous parents are more than 3 times as likely to receive medications for common mood disorders and more than twice as likely to receive medications for psychoses compared with
children of unrelated parents.<ref>{{cite journal|title=[https://doi.org/10.1001/jamapsychiatry.2018.0133 Consanguineous Marriage and the Psychopathology of Progeny: A Population-wide Data Linkage Study]|authors=Maguire, Tseliou, O'Reilly|journal=JAMA Psychiatry|year=2018}}</ref> Also, a positive correlation between consanguinity and schizophrenia has been observed.<ref>{{cite journal|title=[https://doi.org/10.1080/09723757.2017.1368221 Parental Consanguineous Marriages are Associated with Early Age of Onset of Schizophrenia in a Pakistani Cohort]|authors=Fatima et al.|journal=International Journal of Human Genetics|year=2017}}</ref><ref>{{cite journal|title=[https://doi.org/10.1016/j.schres.2010.03.026 Consanguinity and increased risk for schizophrenia in Egypt]|authors=Mansour et al.|journal=Schizophrenia Research|year=2010}}</ref><ref>{{cite journal|title=[https://www.ncbi.nlm.nih.gov/pubmed/24294299 Does consanguinity increase the risk of schizophrenia? Study based on primary health care centre visits]|authors=Bener, Dafeeah, Samson|journal= Mental Health in Family Medicine|year=2012}}</ref>

==See also==
* [[Charles Darwin]], who was married to his cousin
* [[Incest]]
* [[Inbreeding]]

==References==
{{reflist|2|80%}}

[[Category:Sexuality]]
[[Category:Incest]]

Categories: Sexuality, Incest