The overall rate of consanguineous marriage was 38.6% with a mean inbreeding coefficient (alpha) of 0.0185. First cousin marriages (27.9%) were the most common form of consanguineous union, with parallel patrilateral marriage especially favoured.
The data showed that the overall frequency of consanguinity was 50.7% in urban and 86.2% in rural areas. The equivalent mean inbreeding coefficient (α) was 0.0272 and 0.0487 in urban and rural areas, respectively.
Since the Pahlavi era fewer Iranians have practised cousin marriages. There is a strong preference for marrying a first cousin, but no specific preference for the father's brother's daughter. For the quarter of women married after age 21 it was found that the incidence of consanguinity declined to 28%.
Many studies show that the prevalence of consanguineous marriages among Muslim populations is more than in other populations, worldwide; it is approximately 52%, with an average inbreeding coefficient of 0.0312.
The Middle East has uniquely high rates of cousin marriage among the world's regions. Certain Middle Eastern countries, including Saudi Arabia, have rates of marriage to first or second cousins that may exceed 70%. Iraq was estimated in one study to have a rate of 33%.
What country has the highest rate of inbreeding in the world? Although precise per-country data is rare, it is widely accepted that countries in the Middle East, North Africa, and parts of Western Asia have the highest rates of inbreeding in the world.
Data on inbreeding in several contemporary human populations are compared, showing the highest local rates of inbreeding to be in Brazil, Japan, India, and Israel.
In Morocco, consanguinity varies in the range of 19.81–28% [5]. Regional studies showed that the northern regions register higher inbreeding rates. Recent studies have evaluated consanguinity in the global population of the Tangier-Tetouan region as 39.4% and of the Tangier-Tetouan-Al Hoceima region as 24.37% [5, 6].
There is no defined limit as to what is an acceptable level of inbreeding in domestic animal populations. However, inbreeding depression is likely to be more apparent once inbreeding levels get to above 10%.
Self-pollination (mating of an individual to itself) represents the most extreme form of inbreeding. Inbreeding leads to an increase in homozygosity at the expense of heterozygosity.
In Islam, marriages between first cousins are permitted. (Surah Nisa Verse 22-24). Cousin marriage is also permitted in many other religions and civilizations.
This is a common practice globally in many cultures and countries, but it is far more common in Pakistan than in any other country with a high percentage of 55-60% marrying their first cousins. Consanguine marriages are not only common within Pakistan, but also a practice amongst British Pakistani communities.
For Iranians marriage is an event, which must be celebrated not quietly but with glory and distinction. It is the most conspicuous of all the occasions and is celebrated in the presence of a fairly large assembly. In the past the parents and older members of the family arranged almost all marriages.
People of Iran
But the people who are generally known as Persians are of mixed ancestry, and the country has important Turkic and Arab elements in addition to the Kurds, Baloch, Bakhtyārī, Lurs, and other smaller minorities (Armenians, Assyrians, Jews, Brahuis, and others).
For centuries members of Europe's royal families often married their close relatives. The practice, which stretched across countries including France. But it also led to problems. Offspring born to mothers and fathers who share a common ancestry are more vulnerable to birth defects and harmful DNA mutations.
Several genetic disorders have been reported to be frequent among Iranian Jews, in particular, cortico- sterone methyloxydase deficiency type 11, polyglandular syndrome, and rimmed vac- uole myopathy. Based on the data collected in our clinic, recessive and dominant deafness also appear to be frequent.
research on minimum viable population
They created the “50/500” rule, which suggested that a minimum population size of 50 was necessary to combat inbreeding and a minimum of 500 individuals was needed to reduce genetic drift.
An inbreeding coefficient of . 25 signifies the mating of an animal with its parents. This means there is a 25% chance of homozygosity or the sharing of the two exact same alleles for the same gene.
Genetic coefficient of inbreeding (COI) is the most accurate method for measuring inbreeding. Unlike pedigree based COI calculations, genetic COI evaluates the actual pieces of DNA in your dog to identify which proportion traces back to inbreeding.
Moroccans are the second-largest non-EU nationality present in France, with 755,400 people, or 18.4% of the total immigrant population.
Paternal lineage
On average, 65% of the Maghreb's paternal lineages come from North-Africa, 20% come from the Middle East, 10% come from West or East Africa and 5% come from Europe, with possible significant variations depending on the regions.
Studies have confirmed an increase in several genetic disorders due to inbreeding such as blindness, hearing loss, neonatal diabetes, limb malformations, disorders of sex development, schizophrenia and several others.
In Europe, the practice was most prevalent from the medieval era until the outbreak of World War I, but evidence of intermarriage between royal dynasties in other parts of the world can be found as far back as the Late Bronze Age.
Roughly one in every 3,650 or so people in the UK could have been born of extreme incest, a variety that involves parents that are first- or second-degree relatives, according to a new study published in the journal Nature. Studying incest is a challenging task for researchers.
In the video above: What happens to us inside the womb
Based on the data, the researchers estimate one in every 3652 people born in Britain with a European ancestry are inbred.