<h4>Background</h4>Orofacial anomalies occur due to incomplete fusion of developmental lines in the head and neck region. Dental anomalies regarded as the most common orofacial anomalies either in isolated or syndromic forms arise due to genetic and environmental factors. Among genetic influences, consanguineous marriages are considered as a significant predisposition factor in the transmission of congenital defects and several autosomal recessive diseases from one generation to other with an increased risk of detrimental effects on offspring.<h4>Aim</h4>The present study was aimed to evaluate the prevalence and significant association between consanguinity and isolated dental anomalies with that of nonconsanguineous parents among south-Indian population.<h4>Methodology</h4>A total of 116 participants with and without dental anomalies in isolated form pertaining to tooth size, shape, altered morphology, number and eruption were selected followed by brief case history. Participants with a positive history of consanguinity were categorized as Group A while others were categorized under Group B.<h4>Results</h4>Sixty-four out of 116 participants (55.17%) showed positive consanguinity (Group A) among which 18 females (56%) and 14 males (44%) presented with isolated dental anomalies. 12 females (66.6%) and 9 males (64.2%) in Group A showed significance with first cousin (<i>P</i> = 0.00204) whereas no significance was observed in other consanguinity type (<i>P</i> = 0.7287). Nonetheless, the overall frequency of isolated dental anomalies was slightly higher in Group A than Group B that was statistically significant (<i>P</i> = 0.0213).<h4>Conclusion</h4>A positive correlation between dental anomalies among offspring of consanguineous marriages revealed such prevalence may be attributed to increased risk of recessive deleterious gene expression or defective allele carried to offspring.

<h4>Objectives</h4> The etiologies of nonsyndromic cleft lips with or without palate (NS CL/P) are multifactorial, which include consanguineous marriages. The incidence of NS CL/P is relatively high in Indonesia notably in one of Indonesia's tribes whose members frequently marry close cousins. Thus, the purpose of this study is to analysis consanguinity as risk factor of NS CL/P in Sasak tribe, East Lombok, Indonesia MATERIALS AND METHODS:  An observational analysis was made of a collected database of NS CL/P patients treated in social services in regency hospital of Dr. Soejono Selong, East Lombok, Indonesia. Demographic data such as age, gender, address (urban/rural), parent's education, presence or absence of consanguinity, type of clefts, and a three-generation pedigree were collected by interview and hospital medical record. Before analysis, patient information was anonymized and deidentified. From 2016 to 2018, each of 100 cleft and normal subjects with their Sasak parent were audited. The risk factors were analyzed statistically using odds ratio (OR) and chi-squared test.<h4>Results</h4> Consanguineous marriages identified 54 cases (54%), and 10 cases (10%) out of a total each 100 NS CL/P and controls, respectively. The majority of consanguinity (53.7%) was discovered in marriages between first cousins. NS CL/P cases were statistically linked (<i>p</i> = 0.00) with consanguineous marriages (OR: 10; 95% confidence interval: 1.6-3.1); in which the most prevalent case is unilateral cleft lips.<h4>Conclusion</h4> Consanguineous marriage increases the risk of NS CL/P in Sasak tribe, East Lombok, Indonesia. The development of strategies to educate communities on the impacts of culture-consanguineous marriage is required. The genetic inheritance from their ancestor may be responsible for the increased incidence of NS CL/P.

Machine Boseley, Sarah (4 July 2013). "Marriage between first cousins doubles risk of birth defects, say researchers". The Guardian. Retrieved 28 March 2014 Incest ( IN-sest) is sexual activity between close relatives, such as a sibling or parent. This typically includes any kind of sexual activity between people in consanguinity (blood relations), and sometimes those related by lineage. It is condemned and considered immoral in many societies. It can lead to an increased risk of genetic disorders in children in case of pregnancy from incestuous sex. Inc… There are some cultures in Asia which stigmatize cousin marriage, in some instances even marriages between second… In the short term, because incestuous reproduction increases zygosity, deleterious recessive alleles will express themselves more frequently, leading to increases in spontaneous abortions of zygotes, perinatal deaths, and postnatal offspring with birth defects. In the long run, however, because of this increased exposure of deleterious recessive alleles to natural selection, their frequency decreases more rapidly in inbred population, leading to a "healthier" population (with fewer deleterious recessive alleles). The closer the relationship between two persons, the higher the zygosity, and thus the more severe the biological costs of inbreeding. This fact probably explains why inbreeding between close relatives, such as siblings, is less common than inbreeding between cousins. There may also be other deleterious effects besides those caused by recessive diseases. Thus, similar immune systems may be more vulnerable to infectious diseases (see Major histocompatibility complex and sexual selection). A 1994 study found a mean excess mortality with inbreeding among first cousins of 4.4%. A 2008 study also found decreased lifespan among offspring of first cousins, but no difference between lifespans after the second cousin level. A 1990 study conducted in South India found that the incidence of malformations was slightly higher in uncle-niece progeny (9.34%) compared to the first cousin progeny (6.18%). Stillbirth rates were significantly higher among consanguineous couples irrespective of the mother's socioeconomic status, and were higher in uncle-niece mating's compared to first cousin and beyond first cousin unions in both the poor and middle/upper class. Children of parent–child or sibling–sibling unions are at increased risk compared to cousin–cousin unions. Studies suggest that 20–36% of these children will die or have major disability due to the inbreeding. A study of 29 offspring resulting from brother–sister or father–daughter incest found that 20 had congenital abnormalities, including four directly attributable to autosomal recessive alleles.

Background and objective Consanguinity refers to the marital practice between individuals who share blood relations. It is commonly observed in the Middle East, particularly through first-cousin unions. Previous studies have associated consanguineous marriages with an increased risk of genetic disorders and higher infant mortality rates. Much of the research conducted in the United Arab Emirates (UAE) on consanguinity is either outdated or does not specifically address the knowledge, attitudes, and perceptions of our target population. This study aimed to assess the knowledge, attitudes, and perceptions of UAE adults regarding consanguinity and its genetic consequences. Methods This was a cross-sectional study using convenience sampling to target UAE adult residents. A 37-question online survey was created, piloted, and then shared on social media platforms in both English and Arabic. The participants' knowledge, attitudes, and perceptions regarding consanguinity, premarital testing, and genetic disorders were assessed. Data were analyzed using SPSS Statistics version 26 (IBM Corp., Armonk, NY). Results The sample included 447 participants: 172 (38.5%) were men and 275 (61.5%) were women. Regarding nationality, 335 (74.9%) were non-local Arabs, 78 (17.4%) were Emirati nationals, and 34 (7.6%) were non-Arabs. Results show that 186 (41.6%) of participants had good knowledge, while 168 (37.6%) and 93 (20.8%) had moderate and poor knowledge, respectively. Higher knowledge scores were more common among participants with certain demographics, including women, non-local Arabs, healthcare sector employees, and individuals with non-related parents (p < 0.05). Regarding attitudes, 268 (60.0%) of participants had negative attitudes toward consanguinity. Negative attitudes were more frequent among participants with specific demographic characteristics, including female gender, younger age, non-local Arab ethnicity, students, unmarried individuals, and having non-related parents (p < 0.05). Additionally, 402 (90.0%) of participants believed that premarital testing is necessary. Conclusions This study shows that greater knowledge of the health consequences of consanguinity is associated with more negative attitudes toward the practice, indicating that awareness can influence societal perspectives. Demographic factors such as age, gender, and culture have a strong impact on attitudes, emphasizing the need for targeted interventions to shift perceptions of consanguineous marriages across different cultural groups.