Is there any studies/concerns in Turkey about the genetic health of Turks in regions with high consanguineous marriages?
According to
this study from 1994, fertility is high among these couples but "post-neonatal, infant and under-5 mortalities are high in first cousin unions by comparison with non-consanguineous marriages".
The overall rate of consanguineous marriages in Turkey is between 20 and 23 percent.
In India, the Muslim rate of cousin marriage is 22%, with the rate nearly doubling to 40% in Jammu and Kashmir. Pakistan, noted earlier, is the world leader in consanguinity with around 70%; Saudi Arabia is 50+%; Iran and Afghanistan are 30-40%, Iraq 33%, Egypt and Turkey 20+%, and Qatar 54%.
->
https://ieet.org/index.php/IEET2/more/pellissier20120526
"In the latest demographic survey (TDHS-2003), a nationally representative sample of 8075 ever-married women, consanguineous marriages accounted for 22% of the total, which is equivalent to a mean coefficient of inbreeding (alpha) of 0.011. There are changing secular profiles in the rates of consanguinity in general and of the specific sub-types of cousin marriages in particular in Turkey. The prevalence of first cousin marriages among all consanguineous marriages presents a steady decline from one marriage cohort to the next. The changes observed over time may be attributable to several factors such as the increase in educational level of women, the nuclearization of the family system, the mobility from rural to urban settings, a better socioeconomic status of families, an increase in women's labour force participation in formal sectors, lower fertility rates resulting in a smaller number of cousins available for marriage, and an increased awareness of the effects of consanguineous unions on child health in cases where there is an inherited recessive disease in the family."
Source: KOC, I. (2008). PREVALENCE AND SOCIODEMOGRAPHIC CORRELATES OF CONSANGUINEOUS MARRIAGES IN TURKEY.
Journal of Biosocial Science, 40(1), 137-148. doi:10.1017/S002193200700226X
In general, such marriages are becoming less acceptable in the society. Like I said before, there is a huge gap between Turkish and non-Turkish inhabited regions within Turkey. Ethnic Kurds still tend to marry relatives.
However, it is frequently reported in the Turkish media that regions with high figures of consanguineous unions show higher numbers of disabled persons or persons with genetic diseases.
Even Muslim physicians in Eastern Anatolia (Province of Van) are warning people not to marry within the family: "Consanguineous marriages lead to genetic diseases"
http://www.milliyet.com.tr/akraba-evlilikleri-genetik-hastaliklarin-van-yerelhaber-1999120/
Especially in Eastern Anatolia, there is a high number of people with Familial Mediterranean fever due to cousin marriages.
In Bingöl, another Eastern province, 99 infants died last year. 42 of them died due to genetic disorders (metabolic problems etc.) caused by cousin marriages.
The good news is that the figures for 2017 are better, according to the same news article:
http://www.hurriyet.com.tr/halk-sagligi-muduru-bingolde-bebek-olumlerini-40489984
Btw, you have to obtain a health certificate in Turkey in order to get married legally. You get tested for all kinds of STDs, Thalassemias, Rh disease etc. One of the reason why HIV is barely spread in Turkey. Virginity tests are strictly forbidden in Turkey.