Consanguinity and recurrence risk of stillbirth and infant death

Long-term health outcomes from inbreeding in a historical Swedish population: longevity, fertility, and impairments

BACKGROUND

Inbreeding, arising from consanguinity between related parents, has been observed to impact the health of individuals, typically attributed to biological factors. Nevertheless, these effects may be influenced by the social and environmental conditions. The prevalence of consanguineous marriages increased in certain parts of Sweden after it became legal in 1844, which offers a unique opportunity to study and understand the effects of inbreeding on health.

AIM

The objective of this study is to explore the potential impact of inbreeding on the longevity, fertility, and impairments of individuals born in the Skellefteå region, Sweden, between 1890 and 1905, with a follow-up period extending until 1950.

SUBJECTS AND METHODS

The level of inbreeding is calculated using micro-level parish register data and related to longevity, fertility, and impairments using regression analysis.

RESULTS

Inbreeding is shown to be associated with longevity, fertility, and impairments. It seems to affect the risk of stillbirth and impairments and male longevity and fertility.

CONCLUSION

Inbreeding seems to have had a detrimental effect on some health outcomes in this historical population under study.

Screening for obesity in the offspring of first-cousin consanguineous couples: A Phase-I study in Saudi Arabia

Consanguineous or cousin marriages are very common in Saudi Arabia. However, owing to limited studies and insufficient knowledge about genetic diseases/disorders, many couples are unaware of the increased health risks for their offspring. Among the inherited and complex diseases from parents’ consanguinity, obesity is common; therefore, we examined the prevalence of obesity in the offspring of first-cousin consanguineous couples in Saudi Arabia. In this questionnaire-based study, 657 individuals (mean age = 18.7 ± 10.2 years; age range = 2–65 years) who were residing in Riyadh, Saudi Arabia participated. Among them, almost 90% were native Saudis. Participants mean body mass index (BMI) was 24.5 ± 9.1 kg/m2. Sex- stratified demographic details confirmed a significant association between age and BMI (p < .001). We confirmed that adolescents and adults were more prone to develop obesity. Adults and non-Saudi participants were three times more likely to develop obesity if they had first-cousin consanguineous parents than those who did not. Of the 30% of participants who were obese, 100 will be selected for Phase II, in which we plan to perform exome sequencing.

Stillbirth in relation to maternal country of birth and other migration related factors: a population-based study in Norway

BACKGROUND

Migrant women's overall increased risk of adverse pregnancy outcomes is well known. The aim of this study was to investigate possible associations between stillbirth and maternal country of birth and other migration related factors (paternal origin, reason for immigration, length of residence and birthplace of firstborn child) in migrant women in Norway.

METHODS

Nationwide population-based study including births to primiparous and multiparous migrant women (n = 198,520) and non-migrant women (n = 1,156,444) in Norway between 1990 and 2013. Data from the Medical Birth Registry of Norway and Statistics Norway. Associations were investigated by multiple logistic regression and reported as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Primiparous women from Sri-Lanka and Pakistan, and multiparous women from Pakistan, Somalia, the Philippines and Former Yugoslavia had higher odds of stillbirth when compared to non-migrant women (adjusted OR ranged from 1.58 to 1.79 in primiparous and 1.50 to 1.71 in multiparous women). Primiparous migrant women whose babies were registered with Norwegian-born fathers had decreased odds of stillbirth compared to migrant women whose babies were registered with foreign-born fathers (aOR = 0.73; CI 0.58-0.93). Primiparous women migrating for work or education had decreased odds of stillbirth compared to Nordic migrants (aOR = 0.58; CI 0.39-0.88). Multiparous migrant women who had given birth to their first child before arriving in Norway had higher odds of stillbirth in later births in Norway compared with multiparous migrant women who had their first child after arrival (aOR = 1.28; CI 1.06-1.55). Stillbirth was not associated with length of residence in Norway.

CONCLUSIONS

This study identifies sub-groups of migrant women who are at an increased risk of stillbirth, and highlights the need to improve care for them. More attention should be paid to women from certain countries, multiparous women who had their first baby before arrival and primiparous women whose babies have foreign-born fathers.

Stillbirth in relation to maternal country of birth and other migration related factors: a population-based study in Norway

Background

Migrant women’s overall increased risk of adverse pregnancy outcomes is well known. The aim of this study was to investigate possible associations between stillbirth and maternal country of birth and other migration related factors (paternal origin, reason for immigration, length of residence and birthplace of firstborn child) in migrant women in Norway.

Methods

Nationwide population-based study including births to primiparous and multiparous migrant women (n = 198,520) and non-migrant women (n = 1,156,444) in Norway between 1990 and 2013. Data from the Medical Birth Registry of Norway and Statistics Norway. Associations were investigated by multiple logistic regression and reported as odds ratios (ORs) with 95% confidence intervals (CIs).

Results

Primiparous women from Sri-Lanka and Pakistan, and multiparous women from Pakistan, Somalia, the Philippines and Former Yugoslavia had higher odds of stillbirth when compared to non-migrant women (adjusted OR ranged from 1.58 to 1.79 in primiparous and 1.50 to 1.71 in multiparous women). Primiparous migrant women whose babies were registered with Norwegian-born fathers had decreased odds of stillbirth compared to migrant women whose babies were registered with foreign-born fathers (aOR = 0.73; CI 0.58–0.93). Primiparous women migrating for work or education had decreased odds of stillbirth compared to Nordic migrants (aOR = 0.58; CI 0.39–0.88). Multiparous migrant women who had given birth to their first child before arriving in Norway had higher odds of stillbirth in later births in Norway compared with multiparous migrant women who had their first child after arrival (aOR = 1.28; CI 1.06–1.55). Stillbirth was not associated with length of residence in Norway.

Conclusions

This study identifies sub-groups of migrant women who are at an increased risk of stillbirth, and highlights the need to improve care for them. More attention should be paid to women from certain countries, multiparous women who had their first baby before arrival and primiparous women whose babies have foreign-born fathers.

Electronic supplementary material

The online version of this article (10.1186/s12884-018-2140-3) contains supplementary material, which is available to authorized users.

The association of maternal country of birth and education with hypertensive disorders of pregnancy: A population-based study of 960 516 deliveries in Norway

INTRODUCTION

Previous studies estimating the association of maternal country of birth and education with hypertensive disorders of pregnancy (HDP) have shown conflicting results. The aim of the study was to assess the prevalence of HDP and estimate the association of maternal country of birth and education level with preeclampsia/eclampsia and gestational hypertension in Norway.

MATERIAL AND METHODS

We performed a population-based observational cohort study linking two population datasets: The Medical Birth Registry of Norway and Statistics Norway (SSB). Singleton deliveries in Norway between 1999 and 2014 (907 048 deliveries) were stratified by parity. Multiple regression analysis was performed.

RESULTS

In 20% of the deliveries the woman was born outside of Norway. Foreign-born women had lower risk of preeclampsia/eclampsia and gestational hypertension compared with Norwegian-born women. High education reduced the risk for preeclampsia/eclampsia by 34% (adjusted odds ratio 0.66, 95% CI 0.62-0.69), compared with women with secondary education among nulliparous women, and by 39% (adjusted odds ratio 0.61, 95% CI 0.57-0.65) among parous women. Poorly educated women had no increased risk of HDP compared with women with secondary education. Among highly educated nulliparous women the risk of preeclampsia/eclampsia was lower but the risk of gestational hypertension higher compared with women of similar parity with secondary education. Adjustment for confounding variables had minimal effect on these estimates.

CONCLUSIONS

Maternal country of birth and education were associated with HDP. Women with higher education had the lowest risk of HDP, and Norwegian-born women had the highest risk of HDP, regardless of parity and other confounding factors.

Associates of Neonatal, Infant and Child Mortality in the Islamic Republic of Pakistan: A Multilevel Analysis Using the 2012-2013 Demographic and Health Surveys

Objectives Pakistan is one of five nations contributing to half of the world's child mortality and holds under-five mortality rates which are nearly double global targets. Reasons for this shortfall include civil conflicts, political uncertainty, low education, poverty, rural-urban disparities, and limited health care access. The aim of this study was to explore associations between individual characteristics, community factors, and child mortality in Pakistan. Methods Data were derived from the 2012 to 2013 Pakistan Demographic and Health Survey, and included 7399 live births and 380 child deaths. Multivariate, multilevel logistic regression was used to model risk of neonatal, infant and under-five child deaths. Results Seventy-one percent of child deaths occurred during the neonatal period. Significant factors (p < 0.05) associated with lower odds of child mortality included adhering to recommended minimum of 24 months interpregnancy interval and higher household wealth. These were significant for neonatal (OR 0.448; 0.871), infancy (OR 0.465; 0.881), and under-five deaths (OR 0.465; 0.879). Employed mothers had higher odds of neonatal (OR 1.479), infant (OR 1.506), and child mortality (OR 1.459). Likewise, women living in consanguineous marriages had higher odds of infant (OR 1.454) and under-five deaths (OR 1.381). Children in Balochistan, Punjab, and Sindh, regions disproportionately poor, rural with low levels of education, were at highest risk of dying. Conclusions for Practice Findings may assist in designing targeted interventions, developing appropriate public health messaging, and implementing policies designed to lower child mortality. Focusing on lowering rates of maternal poverty, increasing opportunities for education, and improving access to health care could assist in reducing child mortality in Pakistan.

Under-Five Child Mortality and Morbidity Associated with Consanguineous Child Marriage in Pakistan: Retrospective Analysis using Pakistan Demographic and Health Surveys, 1990-91, 2006-07, 2012-13

Objective To assess the combined effect of consanguineous and child marriages (CCM) on children health, which has not previously been explored, either globally or locally. Methods We analyzed secondary data from a series of cross-sectional, nationally representative Pakistan Demographic and Health Surveys 1990-91, 2006-07, and 2012-13. A total of 5406 mothers with 10,164 children were included in the analysis. Child health was assessed by variables such as history of diarrhea, acute respiratory infection (ARI), ARI with fever, Under-5 child mortality (U5CM) and small-size birth (SSB). Associations among variables were assessed by calculating unadjusted Odd Ratios (OR) and adjusted OR (AOR). Results A majority (n = 6,247, 61%) of the births were to mothers having CCM as compare to non-CCM (3917, 39%). There was a significant association between CCM and U5CM during 1990-91 (AOR 1.24, 95% CI 1.03-1.49) and 2006-07 (AOR 1.25, 95% CI 1.05-1.51), and infant mortality in 1990-91 (AOR 1.39, 95% CI 1.05-1.85) and 2006-07 (AOR 1.61, 95% CI 1.17-2.21). A significant association was also found between CCM and SSB infants in the period 2006-07 (AOR 1.19, 95% CI 1.01-1.42) and 2012-13 (AOR 1.22, 95% CI 1.02-1.46). We noted no effect of CCM on diarrhea, ARI, and ARI with fever. Conclusion CCM increases the likelihood of U5CM, infant mortality and SSB infants. Further quantitative and qualitative research should be conducted to assess the effects of environmental, congenital and genetic factors on the health of children born to mothers in CCM.

CONSANGUINEOUS MARRIAGES AMONG IRANIAN MANDAEANS LIVING IN SOUTH-WEST IRAN

Several studies have indicated that consanguineous marriages (unions between biologically related persons) are associated with increased risk of autosomal recessive diseases and several multifactorial traits. Mandaeans are a closed ethno-religious community living in areas of southern Iraq and Iran (Khuzestan Province). There are currently no data on the prevalence of consanguineous marriages among Mandaeans. The present study was carried out in 2016 to determine the prevalence of consanguinity among Iranian Mandaeans living in Khuzestan Province, south-west Iran. A total of 137 couples (urban areas: 79 couples; rural areas: 58 couples) were included in the study. Information on the consanguineous marriages of the subjects was collected through direct interviews. Marriages were classified by the degree of relationship between couples as double first cousins, first cousins, first cousin once removed, second cousins and unrelated marriages. The coefficient of inbreeding (F) was calculated for each couple and the mean coefficient of inbreeding (α) estimated for the population, stratified by rural and urban areas. The overall frequency of consanguinity was found to be 50.7% in urban and 86.2% in rural areas. There was a significant difference between rural and urban areas in types of marriages (χ 2=24.8, df=4, p<0.001) and first cousin marriages (51.8%) were the most common type. The overall α-value was estimated to be 0.0363 for the Iranian Mandaean population.

A perinatal review of singleton stillbirths in an Australian metropolitan tertiary centre

It is estimated that everyday 7000 women worldwide have their pregnancy end with a stillbirth, however, research and data collection on stillbirth remains underfunded. This stillbirth case series audit investigates an apparent rise in stillbirths at a Sydney tertiary referral hospital in Australia. A retrospective case series of singleton stillbirths from 2005–2010 was conducted at Westmead Hospital. Stillbirth was defined as per the Perinatal Society of Australia and New Zealand classification as a death of a baby before or during birth, from the 20th week of pregnancy onwards, or a birth weight of 400 grams or more if gestational age is unknown. A total of 215 singleton stillbirths were identified in a cohort of 28 109, a rate of 7.6 per 1000 singleton births. There was a significant increase in annual stillbirth rate at our institution; the rate exceeded both Australian national and state singleton stillbirth rates. After pregnancy terminations over 20 weeks were excluded from the data, there was no statistical change in the stillbirth rate over time. Congenital anomalies (27%) and unexplained antepartum death (15%) remained as major causes; fetal growth restriction (17%) was also identified as an increasingly important cause, particularly in preterm gestations. Termination of pregnancy after 20 weeks was found to be the cause of rising stillbirth rate at our institution. Local and national data collection on stillbirth should be standardised and should include differentiation of termination of pregnancy as a separate entity so as to accurately assess stillbirth to target appropriate research and resource allocation.

Classic Case Report of Donohue Syndrome (Leprechaunism; OMIM *246200): The Impact of Consanguineous Mating

Donohue syndrome ([DS]; leprechaunism) describes a genetic autosomal recessive disorder that results from the presence of homozygous or compound heterozygous mutations in the insulin receptor gene (INSR; 19p13.3-p13.2).Donohue syndrome is associated with a fatal congenital form of dwarfism with features of intrauterine and postnatal growth retardation, exaggerated hyperglycemia with hyperinsulinism and dysmorphic abnormalities.We present a case of DS owing to the rarity of this syndrome (1 case in every million births). We discuss how the disease presents, its genetic underpinning, and its prevention.The case was encountered in an Arab male born on 1 September, 2014, for consanguineous parents. The delivery was via cesarean section at 37 weeks gestation due to severe intrauterine growth restriction and nonprogress labor term. The patient was admitted to the Neonatal Intensive Care Unit due to infection, and jaundice. Dysmorphic features, abnormalities of the craniofacial region, low birth weight, skin abnormalities, abdominal distension and hypertrichosis were observed. Laboratory examinations showed, hyperinsulinism, increased C-peptide, thrombocytopenia, leucopenia, and anemia.The diagnosis of DS was done based on the combinations of typical dysmorphic characteristics, clinical evaluation, supported by genetic analysis and exaggerated biochemical results. Genetic diagnosis of DS was performed through analysis of DNA via polymerase chain reaction (PCR). A qualitative real-time PCR was used, to monitor the amplification of a targeted DNA molecule during the PCR. Other technique using sequencing of the INSR gene, which permits genetic diagnosis, counseling, and antenatal diagnoses in subsequent pregnancies, were also performed.Treatment of DS is supportive and requires the combined efforts of a multidisciplinary team, which include pediatricians, endocrinologists, dermatologists, and other health care professionals. Currently, treatment with recombinant insulin-like growth factor 1 demonstrates effectiveness, and a combination treatment with insulin-like growth factor binding protein 3 resulted in an increased lifespan.There is a scarcity of genetic information on DS among the Arab population. Consanguinity is one of underlying reasons for the appearance of rare genetic disorders. Inbreeding has long been considered a controversial phenomenon. Genetic counseling and overwhelming the alertness of the negative consequences of consanguinity on public health are warranted.

UK Pakistani views on the adverse health risks associated with consanguineous marriages

This is a qualitative study exploring the perceptions of members from the Pakistani/Kashmiri community living in Luton, UK, on the adverse health risks associated with consanguineous marriages. Rates of stillbirths and infant mortality are higher than the national average in Luton and the existing evidence base suggests that these higher rates may be associated with consanguinity (especially first cousin marriages) in highly consanguineous populations, such as the Pakistani/Kashmiri ethnic group. This qualitative study included 9 focus groups and 10 one to one in-depth interviews (n = 58) with members from the Pakistani/Kashmiri community in Luton during 2012. Audio-recorded transcripts were analysed using framework analysis. Emerging themes included a limited knowledge, opposition to evidence and need for a more culturally sensitive health services approach. Findings from the focus group and interview discussions indicated that participants had a limited and varied understanding of genetic risk and indicated a lack of discussion within the community regarding genetic risk. They also opposed evidence that may link consanguineous marriages with infant mortality, stillbirth or genetic disorders that led to disability. The participants stressed the need for culturally sensitive and locally constructed services for information on genetic risk and services. These findings may be used to address higher rates of infant mortality and adverse health impacts associated with higher rates of consanguinity in Luton and elsewhere, through a partnership approach, improve upon current services and develop culturally appropriate services.

Consanguinity and neonatal death: a nested case-control study

OBJECTIVE

Although numerous studies have found higher rates of abortion and still births following consanguinity (familial marriages), the question of whether consanguinity significantly increases the risk of neonatal death has inadequately been addressed.This study aims to evaluate familial marriage effects on neonatal death in rural areas in Iran.

MATERIALS AND METHODS

In this nested case-control study, 6900 newbornswho were born in rural areas of Kohgiluyeh and Boyerahmad Province (South-West of Iran)were followed till the end of neonatal period, and neonatal death was the outcome of interest. Subsequently 97 cases and 97 controls were selected in study cohort by using risk set sampling model. Crude and adjusted odds ratios (OR) were estimated by usinga conditional logistic regression model.

RESULTS

In the final model, prematurity (OR = 5.57), low birthweight (LBW) (OR = 7.68), consanguinity (first cousins) (OR = 5.23), C-section (OR = 7.27), birth rank more than 3 (OR = 6.95) and birthsinterval less than 24 months (OR = 4.65) showed significant statistical association with neonatal mortality (p < 0.05).

CONCLUSION

According to our findings, after adjusting the effects of other significant risk factors, familial marriageto first cousins is considered asan important risk factor for neonatal death.

Consanguinity and late fertility: spatial analysis reveals positive association patterns

The role of consanguinity on human complex traits is an important and controversial issue. In this work we focused on the Sardinian population and examined the effect of consanguineous unions on late female fertility. During the last century the island has been characterized by a high incidence of marriages between relatives, favoured by socio economic conditions and geographical isolation, and by high fertility despite a widespread tendency to delay reproduction. Through spatial analysis techniques, we explored the geographical heterogeneity of consanguinity and late fertility, and identified in Central-Eastern Sardinia a common area with an excess of both traits, where the traits are positively associated. We found that their association did not significantly affect women's fertility in the area, despite the expected negative role of both traits. Intriguingly, this critical zone corresponds well to areas reported by previous studies as being peculiar for a high frequency of centenarians and for lower risk in pregnancy outcome. The proposed approach can be generally exploited to identify target populations on which socioeconomic, biodemographic and genetic data can be collected at the individual level, and deeper analyses carried out to disentangle the determinants of complex biological traits and to investigate their association.

Ethnic Variation in Oral Cleft Occurrence in Denmark 1981–2002

Objective

To examine differences in oral cleft (OC) occurrence based on maternal only and parental country of origin in Denmark from 1981 to 2002.

Methods

Data on all live births from the Danish Medical Birth Register from 1981 to 2002 were linked with the Danish Facial Cleft Database. Cleft cases were categorized into isolated and nonisolated cleft lip with or without palate (CL/P) and cleft palate only (CP). Birth prevalence was calculated as cases per 1,000 live born children by maternal country of origin, world region, and mixed parental groups.

Results

We identified 3094 OC cases among 1,319,426 live births. Danish-born women had an OC birth prevalence of 2.38 with a 95% confidence interval (CI) (2.29–2.47) and foreign-born women a significant lower prevalence of 2.01 (CI, 1.77–2.27). This difference was explained by a lower isolated CL/P birth prevalence among foreign-born women of 0.97 (CI, 0.81–1.16) versus 1.35 (CI, 1.28–1.41). No significant differences were seen for the remaining subtypes. Parents with the same foreign country of origin had a lower overall OC (1.63; CI, 1.35–1.94) and isolated CL/P (0.76; CI, 0.57–0.99) birth prevalence than Danish-born parents. This was not the case for any of the mixed parental groups. Overall and subtype prevalence rates varied according to maternal categories of world region.

Conclusion

In this study we found differences in OC occurrence among all live births in the Danish population based on maternal country of origin from 1981 to 2002. Danish-born women had higher OC and isolated CL/P birth prevalence compared with foreign-born women.

Estimating the inbreeding depression on cognitive behavior: a population based study of child cohort

BACKGROUND

Cognitive ability tests are widely assumed to measure maximal intellectual performance and predictive associations between intelligence quotient (IQ) scores and later mental health problems. Very few epidemiologic studies have been done to demonstrate the relationship between familial inbreeding and modest cognitive impairments in children.

OBJECTIVE

We aimed to estimate the effect of inbreeding on children's cognitive behavior in comparison with non-inbred children.

METHODOLOGY

A cohort of 408 children (6 to 15 years of age) was selected from inbred and non-inbred families of five Muslim populations of Jammu region. The Wechsler Intelligence Scales for Children (WISC) was used to measure the verbal IQ (VIQ), performance IQ (PIQ) and full scale IQ (FSIQ). Family pedigrees were drawn to access the family history and children's inbred status in terms of coefficient of inbreeding (F).

RESULTS

We found significant decline in child cognitive abilities due to inbreeding and high frequency of mental retardation among offspring from inbred families. The mean differences (95% C.I.) were reported for the VIQ, being -22.00 (-24.82, -19.17), PIQ -26.92 (-29.96, -23.87) and FSIQ -24.47 (-27.35,-21.59) for inbred as compared to non-inbred children (p<0.001) [corrected].The higher risk of being mentally retarded was found to be more obvious among inbred categories corresponding to the degree of inbreeding and the same accounts least for non-inbred children (p<0.0001). We observed an increase in the difference in mean values for VIQ, PIQ and FSIQ with the increase of inbreeding coefficient and these were found to be statistically significant (p<0.05). The regression analysis showed a fitness decline (depression) for VIQ (R2 = 0.436), PIQ (R2 = 0.468) and FSIQ (R2 = 0.464) with increasing inbreeding coefficients (p<0.01).

CONCLUSIONS

Our comprehensive assessment provides the evidence for inbreeding depression on cognitive abilities among children.

Is consanguinity prevalence decreasing in Saudis?: A study in two generations

BACKGROUND

Saudi population is unique in that there is a strong preference for cousin marriages in the general population. We studied the prevalence of consanguinity in educated Saudi females and compared the results with the results obtained in their parents, to access if a generation difference in which extensive educational activities have prevailed to inform the people of the influence of cousin marriages on health, has made any difference in prevalence of consanguineous marriages.

METHOD

A total of 600 Saudi women (421 university students and 179 women attending outpatients' clinics) were interviewed about their own and their parents' consanguinity.

RESULTS

The total consanguinity (first and second cousins) was 29.7% in the parents. Consanguinity was significantly higher among the daughters than the parents, where 37.9% of the 293 married women had consanguineous marriages. The prevalence of consanguinity was studied in different age groups, though no significant pattern was observed. A strong correlation was found between consanguinity of parents and their daughters; consanguinity was highest (52.3%) in the daughters of parents who were themselves consanguineous.

CONCLUSION

The results did not reveal any decrease in the prevalence of consanguinity over a generation. This shows that the tradition of marrying within the family is a preferred practice, despite the awareness that certain genetic disorders occur at a higher frequency in cousin marriages. There is a need at the primary health care level to inform the public of the consequences of this common practice.

TYPES OF MARRIAGES, POPULATION STRUCTURE AND GENETIC DISEASE

A high occurrence rate of consanguineous marriages may favour the onset and increased frequency of autosomal recessive diseases in a population. The population of Monte Santo, Bahia, Brazil, has a high frequency of rare genetic diseases such as mucopolysaccharidosis type VI, whose observed frequency in this population is 1:5000, while the incidence of this disease recorded in other regions of the world varies from 1:43,261 in Turkey to 1:1,505,160 in Switzerland. To verify the influence of consanguineous marriage on the increased frequency of observed genetic diseases in this population, the population structure and frequency of different types of marriage during different time periods were evaluated. A total of 9765 marriages were found in an analysis of parish marriage records from the city. Over three periods, 1860–1895, 1950–1961 and 1975–2010, the inbreeding rates were 37.1%, 13.2% and 4.2% respectively. Although there was a high rate of inbreeding, endogamic marriages were the dominant marriage type in all three periods. In the most recent period, there was an increase in the number of exogamous marriages and those among immigrants, but most of these occurred among individuals from cities that neighbour Monte Santo. The low rate of migration and high frequency of endogamic and consanguineous marriages show that growth of this population is predominantly internal and could explain the occurrence, and increase in frequency, of recessive genetic diseases in the city.

In-hospital neonatal mortality and the role of consanguinity

BACKGROUND

Consanguinity which increases the risk of genetic disorders has been implicated at times in infant mortality. The aim of this study was to determine the association between consanguinity and in-hospital mortality in newborns.

METHODS

Data was collected prospectively on all births from 26 hospitals in Lebanon from January 2004 to December 2008 and admitted to the National Collaborative Perinatal Neonatal Network. Secondary analysis was done on 65,402 singletons, after exclusion of stillbirths, infants of multiple gestation and infants of second cousin progeny.

RESULTS

In-hospital mortality was 6.7 per 1000 live births (439/65,402). The rate of first cousin marriage was 9.9%. Consanguinity was significantly associated with in-hospital mortality (odds ratio 2.4; 95% confidence interval (CI): 1.8, 3.1); consanguinity remained a significant predictor of mortality (odds ratio 1.8 [95% CI: 1.2, 2.9]) after adjusting for maternal age and education, crowding index, history of abortion, prenatal care, mode of delivery, gender, birthweight and apgar score at 5 minutes.

CONCLUSIONS

This association of consanguinity with in-hospital mortality points to potential genetic factors leading to this increased risk. Designing public health interventions, including raising the awareness and taking into consideration such risks in neonatal mortality studies are indicated.

The practice of consanguineous marriage in Oman: prevalence, trends and determinants

The practice of consanguineous marriage has been the culturally preferred form of marriage in most Arab and the Middle Eastern countries, including Oman, but due to a paucity of population-based data in the past there is a dearth of information about its form and dynamics in Oman. Recent national-level surveys allow this gap to be filled. This paper examines the prevalence, trends and determinants of consanguineous marriages in Oman using data from the 2000 Oman National Health Survey. The results indicate a very high prevalence of consanguineous marriage in Oman, as more than half (52%) of marriages are consanguineous. First cousin unions are the most common type of consanguineous unions, constituting 39% of all marriages and 75% of all consanguineous marriages. The study observed various patterns of consanguinity, some of them common with other Arab nations, and some unique in nature. Women's age at marriage, employment, place of childhood residence and geographical region appear to be significant determinants of consanguineous marriages. Consanguineous marriage shows a strong association with marital stability, early age at marriage and early-age childbearing. There has been no appreciable change in the prevalence of consanguineous unions in Oman over the last four decades despite massive socioeconomic development and modernization. However, recent marriage cohorts show slight declining trends. The results suggest that consanguinity is likely to remain stable in the future or decline at a slow rate. Specific health education and genetic counselling should be followed in line with WHO recommendations to minimize the negative health consequences of consanguinity for child health.

Consanguineous marriages : Preconception consultation in primary health care settings

Consanguinity is a deeply rooted social trend among one-fifth of the world population mostly residing in the Middle East, West Asia and North Africa, as well as among emigrants from these communities now residing in North America, Europe and Australia. The mounting public awareness on prevention of congenital and genetic disorders in offspring is driving an increasing number of couples contemplating marriage and reproduction in highly consanguineous communities to seek counseling on consanguinity. Primary health care providers are faced with consanguineous couples demanding answers to their questions on the anticipated health risks to their offspring. Preconception and premarital counseling on consanguinity should be part of the training of health care providers particularly in highly consanguineous populations.

Does telomere length mediate associations between inbreeding and increased risk for bipolar I disorder and schizophrenia?

We have recently found that consanguinity is a risk factor for bipolar I disorder (BP1) and schizophrenia (SZ) in Egypt. Inbreeding has been associated with increased cellular stress and impaired physiological function in plants and animals. Previous studies have reported that telomere length (TL), an index of oxidative stress and cellular senescence is significantly reduced among patients with SZ or mood disorders compared with control individuals. Hence we evaluated TL as a possible mediator of the observed association between consanguinity and BP1/SZ risk. Patients with BP1 (n=108), or SZ (n=60) were compared with screened adult controls in separate experiments. TL was estimated using a quantitative PCR (qPCR) based assay. The inbreeding coefficient/consanguinity rate was estimated in two ways: using 64 DNA polymorphisms ('DNA-based' rate); and from family history data ('self report'). Significant correlation between TL and DNA based inbreeding was not observed overall, though suggestive trends were present among the SZ cases. No significant case-control differences in TL were found after controlling for demographic variables. In conclusion, reduced TL may not explain a significant proportion of observed associations between consanguinity and risk for BP1/SZ.

Association between healthy life expectancy at birth and consanguineous marriages in 63 countries

In order to investigate the association between mean inbreeding coefficient (α) and healthy life expectancy at birth (HALE; years) the present ecological study on 63 countries was done. Statistical analysis showed that HALE negatively and positively correlated with log(10)α and log(10)GNI per capita, respectively (p<0.001). It should be noted that log(10)α and log(10)GNI per capita were significantly correlated with each other (p<0.001). After controlling for log(10)GNI per capita, significant negative correlations between log(10)α and HALE were observed. The countries were stratified according to their GNI per capita into low- and high-income countries. In countries with high income, after controlling for log(10)GNI per capita, the correlation between HALE at birth and log(10)α was significant (for males r=-0.399, df=32, p=0.001; for females r=-0.683, df=32, p<0.001). In high-income Asian and African countries, where consanguineous marriage is common, after controlling for log(10)GNI per capita, the correlation between HALE at birth and log(10)α was significant (for males r=-0.819, df=8, p=0.004; for females r=-0.936, df=8, p<0.001). It seems that consanguinity influences HALE independent of country income.

Stillbirth among foreign-born women in Sweden

BACKGROUND

The aims of this study were: (i) to investigate stillbirth risk in offspring to foreign-born women by region of birth; (ii) if disparities in risks can be explained by socio-economic factors, pregnancy complications or maternal morbidity; and (iii) if the risk varies by time since immigration.

METHODS

This was a population-based register study with data from the Swedish Medical Birth Register and socio-economic variables from national income and population registers. We studied single births from 1992 to 2005, and included 219,832 births to foreign-born women and 1,094,146 births to Swedish-born women. Logistic regression analysis was used to calculate odds ratios (ORs), using 95% confidence intervals (CIs).

RESULTS

In all, 4104 antepartal and 255 intrapartal stillbirths occurred. Compared with births to Swedish women, the OR of stillbirth was 2.27 (95% CI 1.84-2.80) for births to women from Africa and 1.41 (95% CI 1.22-1.64) for births to women from Middle East, after adjustment for confounding factors. The risk of stillbirth was higher in immigrants who had been in Sweden for a short time period (<5 years) compared with those who had been in Sweden for a longer period, OR 1.21 (95% CI 1.05-1.40).

CONCLUSIONS

The risk of stillbirth in immigrant women varies by region of birth and time since immigration, being highest in women from Africa and the Middle East, and the recently settled. Further studies are needed to identify the mechanisms behind these patterns.

PREVALENCE OF CONSANGUINEOUS MARRIAGES AMONG IRANIAN GEORGIANS

Consanguineous marriage – marriage between relatives – has received a great deal of attention as a potential risk factor for many adverse health outcomes. The present cross-sectional study was done in order to illustrate the prevalence and types of consanguineous marriages among Iranian Georgians living in Frydoonshahr (Isfahan province, central Iran). Data on consanguineous marriages were collected using a simple questionnaire. The total number of couples in this study was 646. Consanguineous marriage was classified by the degree of relationship between couples. First cousin marriages (14.2%) were the most common type of consanguineous marriages, followed by second cousin (7.0%), beyond second cousin (1.5%) and first cousin once removed (0.6%). The mean inbreeding coefficient (α) was calculated as 0.0104 for the population. The present study shows that the study population, as other Iranian populations, has a high level of consanguinity.

High perinatal mortality rate among immigrants in Brussels

BACKGROUND

The relation between immigration status and perinatal mortality is unclear. The objective of this study is to describe and measure inequalities in perinatal mortality and causes of perinatal deaths according to maternal nationality and socioeconomic status.

METHODS

A population-based cohort study related to all babies born during the period of 1998-2006 whose mothers were living in Brussels, irrespective of the place of delivery. Perinatal and post-perinatal mortality were analysed according to the nationality and sociodemographic characteristics of the mothers at birth. We used logistic regression to estimate the odds ratios (ORs) for the association between mortality and nationality.

RESULTS

The women of sub-Saharan Africa experience a 50% excess in perinatal mortality, which primarily reflects a high rate of preterm deliveries and low birth weight, as well as a low socioeconomic level. Paradoxically, despite their favourable rates of preterm and low-birth-weight births, Maghrebian and Turkish women experience a strong excess (50-70%) of perinatal mortality caused primarily by congenital anomalies. Differences in age, parity distributions and multiple births play no significant role, and the excess does not reflect low socioeconomic levels. This excess of perinatal mortality contrasts with the absence of an excess of post-perinatal mortality.

CONCLUSION

In Brussels, patterns of inequalities in perinatal mortality and causes of perinatal deaths vary according to nationality; perinatal mortality is increased in particular ethnic groups independently of socioeconomic status and maternal characteristics.

Does consanguinity lead to decreased incidence of breast cancer?

BACKGROUND

In the Middle East region, consanguinity remains to be a central feature where it has shown an increasing trend. Breast cancer is an extremely complex disease, characterized by a progressive multistep process caused by interactions of both environmental and genetic factors.

AIM

The aim of this study was to examine the possible effect of consanguinity on the risk of breast cancer in a population with a high rate of consanguinity and find the associated risk-modifying factors.

SUBJECTS AND METHODS

The study included 167 Qatari and other Arab expatriates women with breast cancer and 341 age and ethnicity matched control women. A questionnaire that included the socio-demographic information, type of consanguinity, medical history, life style habits, dietary intake and tumor grade was designed to collect, the information of cases and controls. A total number of 214 breast cancer patients were approached and 167 cases completed the questionnaires with a response rate of 78%. Of the 417 healthy women who agreed to participate in this study, 341 responded to the questionnaire (81.8%).

RESULTS

The study revealed that the rate of parental consanguinity was lower in breast cancer patients (24%) than in controls (32.3%) (p=0.062). Female controls were slightly younger (46.5+/-11.9) than breast cancer patients (48.4+/-10.7). Breast cancer incidence was significantly higher in Qatari women (34.1%) compared to other Arab women (65.9%) (p=0.034). A significant difference was noted only in occupation of the studied women between cases and controls (p<0.001). Overweight (46.7%) and obesity (32.9%) were significantly higher in female breast cancer patients compared to controls (p=0.028). Overall, the mean coefficient of consanguinity was lower in breast cancer patients (0.014) than in controls (0.018) (p=0.0125). Family history of breast cancer was significantly more often in breast cancer patients (14.4%) than in controls (6.2%) (p=0.002). However, the family history of breast cancer was more often positive in cases of non-consanguineous parents (15.7%) than cases of consanguineous parents (10.0%).

CONCLUSION

The present study revealed the lack of association between of breast cancer and the parental consanguinity in Arab women residing in Qatar. The family history of breast cancer and the body mass index (BMI) are highly associated with breast cancer.

Parental consanguinity is associated with a seven-fold increased risk of progressive encephalopathy: a cohort study from Oslo, Norway

BACKGROUND/OBJECTIVE

Progressive encephalopathy (PE) is a heterogeneous group of individually rare diseases, many with an autosomal recessive mode of inheritance. We estimated the increased risk of PE associated with consanguinity.

PATIENTS AND METHODS

Using a historic cohort study design, the exposures were country of origin (Pakistan versus Norway) and consanguinity. We included children living in Oslo, born between 1985 and 2003. PE cases were retrieved from an electronic registry of diagnoses coded according to the International Classification of Diseases. Incidence rates were calculated for country of origin. We also estimated population attributable risks caused by consanguinity.

RESULTS

We identified 30 cases per 79 704 person years with Pakistani origin and 35 cases per 658 932 person years with Norwegian origin. This gave incidence rates of 37.6 and 5.3 per 100 000 person years, whereas the incidence rate ratio was 7.1 (95% CI: 4.2-11.9). The incidence rates of consanguineous versus non-consanguineous of Pakistani origin were 59.6 and 18.7 per 100 000 person years. The incidence rate ratio was 3.2 (95% CI: 1.4-7.2), whereas the incidence rate ratio of non-consanguineous Pakistani versus non-consanguineous Norwegian origin was 3.5 (95% CI: 1.6-7.6). The incidence rate ratio between consanguineous Pakistanis and Norwegians was 11.2. The population attributable risk due to parental consanguinity was 50.3% in the Pakistani sub-population.

CONCLUSIONS

We found a seven-fold increased risk of PE in the general Pakistani population, and an eleven-fold increased risk in consanguineous Pakistanis. Pakistani origin by itself was also an independent risk factor. Avoidance of consanguinity in the Pakistani population would result in at least 50% reduction of PE in that group.

Consanguinity in Qatar: knowledge, attitude and practice in a population born between 1946 and 1991

From March 2007 to March 2008 a cross-sectional study was conducted in Qatar to estimate the prevalence of consanguinity among Qataris and to assess their knowledge of the risks and their attitudes towards the practice. A secondary objective was to test the acceptability of sixteen Likert-style questions within the Qatari population. Face-to-face interviews using a 70-item structured questionnaire were conducted by three native Arabic-speaking medical students with 362 Qatari employees. Where consanguinity existed between the employee's parents, a diagram of the consanguinal relationship (phylogram) was completed. The response rate was 93%. By phylogram, 22% of participants reported a cousin relationship between their parents (consanguinal relationship) and another 15% reported that their parents were from the same tribe (affinal relationship). With respect to their own marital decision, 68% of the respondents had been married at least once. By phylogram, 35% of these reported a consanguineous relationship (first marriage), 9% reported only an affinal relationship and 56% reported that they were not married to a blood relative. Results on the sixteen Likert-style attitude questions were stratified by consanguinity status of parents and of self. In the stratification by consanguinity status of parents the top five attitudes differed by group but there appeared to be more similarity between the consanguinal and only tribal groups. Attitudinal results were stratified by sex. Results showed that the males had a stronger belief in several of the attitudes than females with the exception of causation of genetic abnormalities and health problems. The phylogram was shown to collect more detailed and explicit data than hard-coding. With respect to knowledge, the results showed that knowledge was imperfect with high proportions of participants not knowing that consanguinity has been implicated in autosomal recessive diseases such as thalassaemia, inborn errors of metabolism, deafness, anomalies of the extremities and specific congenital heart defects. Additionally, a sizeable proportion of the participants did not know that a more distant cousin marriage (e.g. third cousin) theoretically could be a less genetically risky choice to potential offspring than a closer cousin marriage (half-first cousin). These results indicate that more effort needs to be made in developing public health strategies to improve the population's understanding of the cost-benefit analysis involved in contracting consanguineous marriages given the goal of healthy offspring.

The genetics of inbreeding depression

Inbreeding depression - the reduced survival and fertility of offspring of related individuals - occurs in wild animal and plant populations as well as in humans, indicating that genetic variation in fitness traits exists in natural populations. Inbreeding depression is important in the evolution of outcrossing mating systems and, because intercrossing inbred strains improves yield (heterosis), which is important in crop breeding, the genetic basis of these effects has been debated since the early twentieth century. Classical genetic studies and modern molecular evolutionary approaches now suggest that inbreeding depression and heterosis are predominantly caused by the presence of recessive deleterious mutations in populations.

Consanguinity and reproductive wastage in the Palestinian Territories

Many studies have found that consanguinity poses a threat to child mortality and health and can also pose a threat to offspring survival before birth. However, there are conflicting findings with some studies having found no increased risk on offspring survival associated with consanguinity. Data from a population-based survey conducted in 2004 in the Palestinian Territories was used to assess the risk of consanguinity on offspring survival. The analysis was conducted on 4418 women aged 15-49 who were asked whether or not they had experienced a stillbirth or a spontaneous abortion. These two outcomes were combined together for the analysis of reproductive wastage. Multivariable negative binomial regression was conducted to calculate the incidence risk ratios (IRR) for each region in the Palestinian Territories separately. The strongest risk factors for reproductive wastage, after controlling for other variables, were found to be consanguinity, age and parity with age presenting the highest IRRs. Standard of living, locality type, education level, women's employment and past intrauterine device use were not found to be significant risk factors for reproductive wastage. In the West Bank only first cousin level of consanguinity was found to be significant and 'hamola' level (or from same family clan) lost its significance after adjusting for other variables. In the Gaza Strip both the first cousin and 'hamola' levels of consanguinity were significant and presented almost equal IRRs of 1.3. In conclusion, consanguinity was found to be a significant risk factor for reproductive wastage.

Decrease in consanguinity among parents of children born in Norway to women of Pakistani origin: a registry-based study

AIMS

To describe the prevalence of consanguinity among Norwegian Pakistani parents in the period from 1995 to 2005.

METHODS

All first births to women of Pakistani origin in 1995-2005 (n = 1962) were identified by linking the Medical Birth Registry of Norway with information on country of origin and country of birth from Statistics Norway. Prevalence ratios (PRs) and prevalence differences were calculated by multiple binomial regression analyses with adjustment for maternal age and education. Women born in Pakistan who gave birth in Norway in 1995-97 formed the reference group.

RESULTS

The proportion of women who were consanguineously related to their co-parent decreased from 45.5% in 1995-97 to 27.3% in 2002-2005 among those who were born in Pakistan, and from 48.3% to 18.8% among women of Pakistani origin who were born in Norway. The proportion of women who were related to their co-parent as first cousin decreased from 37.7% to 24.7% among women born in Pakistan, and from 43.3% to 16.7% among women of Pakistani origin who were born in Norway. The proportion of births to women with an unrelated co-parent increased by 25% for women born in Pakistan (PR = 1.25, 95% confidence interval (CI) = 1.12-1.39), and by 53% for women of Pakistani origin born in Norway (PR = 1.53, 95% CI = 1.35-1.74).

CONCLUSIONS

In contrast to previous reports from the UK, our analysis suggests that there is a decrease in the proportion of consanguineously related parents of children born to women of Pakistani origin in Norway.

Consanguinity and adverse pregnancy outcomes: the north of Jordan experience

This cross-sectional study was carried out to assess the association between consanguineous marriages and adverse pregnancy outcome in the north of Jordan. Women delivered in four major hospitals in the north of Jordan between April 2007 and May 2007 were included in the study. Non-Jordanian women and women with multiple pregnancies were excluded. Mothers answered a pilot-tested structured questionnaire administered by trained personnel in the maternity ward. Data regarding pregnancy outcomes were obtained from the patients' individual records. A total of 3,269 women with a mean age of 27.2 (SD 6.6) years were included. About 49% of women had consanguineous marriages. Consanguineous marriages were significantly associated with low birth weight delivery (13.9% vs. 10.1%), preterm delivery (19.9% vs. 12.3%), and births with congenital anomalies (4.1% vs. 0.8%) compared with non-consanguineous marriages. In the multivariate analysis, consanguinity was significantly associated with preterm delivery (OR = 1.5, 95% CI 1.2, 1.9), and congenital malformations (OR = 6.5, 95% CI 2.8, 15.3). In conclusions, this study supports the association between consanguinity and some adverse pregnancy outcomes.

Association among education level, occupation status, and consanguinity in Tunisia and Croatia

AIM

To investigate the association between education level, occupation status (a proxy for socio-economic status), and consanguinity in 2 large data sets from Tunisia and Croatia countries with different attitudes toward consanguinity.

METHODS

The sample of 1016 students, attending 5 university institutions in Monastir, Tunisia, were interviewed about the educational level and occupation status of their parents and the degree of parental relatedness. In Croatia, a sample of 1001 examinees from 9 isolated island populations was interviewed about their own educational level, occupation status, and consanguinity.

RESULTS

Prevalence of consanguinity (offspring of second cousins or closer) among 1016 Tunisian students was 20.1%, and 9.3% among 1001 Croatian isolates. In Tunisia, the association between consanguinity and both parental degree of education and parental occupation status was highly significant in women (P<0.001), but not significant in men. In Croatia, no statistically significant associations were noted, although there was a consistent trend of increased prevalence of consanguinity with lower education level or occupation status in both genders, but more pronounced in women.

CONCLUSION

Association between education level, socio-economic status, and consanguinity needs to be taken into account in inbreeding studies in human populations. The relationship may be specific for each studied population and highly dependent on the cultural context. It is generally more pronounced among women in most settings.

Stillbirth and Bereavement: Guidelines for Stillbirth Investigation

This document has been archived because it contains outdated information. It should not be consulted for clinical use, but for historical research only. Please visit the journal website for the most recent guidelines.

Infant mortality, ethnicity, and genetically determined disorders in The Netherlands

BACKGROUND

Infant mortality of ethnic minorities in The Netherlands (10% of the population) is twice as high as in the indigenous Dutch population. Causes of death are different for the diverse migrant groups.

METHODS

Hospital records of nearly 600 infants who died in the four major cities between 1995 and 1998 were analysed according to the cause of death, ethnicity, and possible heredity.

RESULTS

There was a four to five times higher proportion of hereditary causes of death in the Moroccan and Turkish population, compared with the Surinamese/Antillians and indigenous Dutch.

CONCLUSIONS

This might be explained by a high inbreeding coefficient as three-quarters of the marriage partners are recruited from the home villages and between a quarter and a third of these marriages are between first cousins. Health promotion activities in The Netherlands have not been successful so far. Preconception genetic counselling might help in reducing these differences.

The heavier the better? Birthweight and perinatal mortality in different ethnic groups

BACKGROUND

Mother's ethnicity is associated with her baby's birthweight and risk of perinatal mortality. Given the close relation between birthweight and perinatal mortality, we explored whether ethnic differences in birthweight explain ethnic differences in perinatal mortality.

METHODS

Data on all births to mothers born in Norway (808 658), Pakistan (6854), Vietnam (3283) and North Africa (1461) from 1980 to 1995 were obtained from the Medical Birth Registry of Norway. The associations between birthweight and perinatal mortality among ethnic groups were analysed using univariate and multivariate methods.

RESULTS

Mean birthweights were low for Vietnamese and Pakistani mothers (3202 g, 3244 g) and high for Norwegian and North African mothers (3530 g, 3559 g). Mean birthweights were largely unrelated to perinatal mortality, which was lowest for Vietnamese (8.2/1000, 95% CI: 5.1-11.3) and highest for Pakistanis (14.9/1000, 95% CI: 12.0-17.7). Intermediate perinatal mortality rates were found among Norwegians (9.5/1000, 95% CI: 9.3-9.7) and North Africans (9.6/1000, 95% CI: 4.6-14.6). Further comparison of weight-specific mortality rates between the two largest ethnic groups showed the low birthweight paradox, where among low-weight births, perinatal mortality was lower among Pakistani than among Norwegian babies. However, adjustment to a relative birthweight scale (units of standard deviations from population-specific mean value) revealed higher rates of weight-specific mortality among Pakistanis across the entire range of birthweights. Multivariate adjustment for relative birthweight and other factors did not change these results.

CONCLUSIONS

Differences in perinatal mortality between the ethnic groups were not explained by differences in mean birthweight. Paradoxical differences in birthweight-specific mortality rates could be resolved by adjustment to a relative scale.

Lay perceptions of genetic risks attributable to inbreeding in Pakistan

Pakistan along with many other West and South Asian countries has a very high prevalence of consanguineous, especially close cousin, marriages. Although there is substantial empirical information on offspring morbidity and mortality attributable to parental consanguinity, population-based information on how communities in general, and women in particular, perceive the health risks associated with consanguineous unions is limited. This paper considers community perceptions of health effects associated with consanguineous marriages using qualitative data from 15 focus group discussions and 294 in-depth interviews. The study was conducted in four low-income, multi-ethnic, and multi-religious communities in Karachi, the principal commercial center of Pakistan. The results show a general lack of awareness of the possible adverse health effects of consanguineous marriage. In cases where a link between consanguinity and ill health was acknowledged, it often centered on the familial origins of non-communicable disorders such as diabetes and hypertension or infectious diseases such as tuberculosis. Belief in fate and the "evil eye" was widespread across all ethnic and religious groups. Many respondents did not agree with medical explanations of a genetic mode of disease inheritance, even in cases where there was an affected child in the family. The absence of a uniform manifestation of disease among all children of a couple who were identified as carriers of a specific mutation added to the confusion among participants. The study highlights the need for further quantification of risks associated with consanguinity and a need for provision of appropriate information to primary-care clinicians and also to communities. The likely impact of increasing morbidity attributable to inbreeding on the health care system in resource poor settings is also discussed.

Consanguinity decreases risk of breast cancer--cervical cancer unaffected

Marriages between third-degree and more distant relatives are common in many parts of the world. Offspring of consanguineous parents have increased morbidity and mortality related to recessive gene disorders. In a population with a high frequency of consanguinity, we examined the frequency of breast cancer (related in part to tumour genes) and cervical cancers (related to virus infection) among offspring of consanguineous and non-consanguineous parents. Study was done prospectively in the United Arab Emirates. Selected were married female citizens, ages 40-65, who attended 12 primary health care clinics for whatever reason. In a face-to-face interview, subjects were asked: (a) about consanguineous marriages in family; (b) if they have or have had breast or cervical cancer; (c) about family history of cancer, cancer screening and other parameters. Tumour diagnosis was confirmed by review of medical records. Of 1750 women invited into study, 1445 (79%) could be used in analysis. Among 579 (40%) women of consanguineous and 866 (60%) of non-consanguineous parents there were 24 and 54 with breast cancer, respectively (RR = 0.66, CI 0.42 - 1.06). In the 40 to 50 age group, breast cancer reported 13 of 446 women of consanguineous and 37 of 633 of non-consanguineous parents (RR = 0.50, Cl 0.27 - 0.93). Cervical cancer had 15 women in consanguineous and 32 in non-consanguineous group (RR = 0.70, Cl 0.38 - 1.28). Number of families with history of breast cancer in consanguineous and non-consanguineous group was 21 and 23, respectively (P = 0.29). The cancer screening rates and other variable values had fairly balanced distribution between the 2 groups. Having consanguineous parents decreases the risk of breast cancer especially in younger women, risk of cervical cancer being unaffected.