A study of possible deleterious effects of consanguinity

A critical systematic review and meta-analyses of risk factors for fertility problems in a globalized world

Globally, fertility awareness efforts include well-established risk factors for fertility problems. Risks disproportionately affecting women in the Global South, however, are neglected. To address this gap, we conducted a systematic review and meta-analyses of relevant risk factors to examine the association between risk factors and fertility problems. MEDLINE, Embase, Cochrane Library, regional databases and key organizational websites were used. Three authors screened and extracted data independently. Studies assessing exposure to risk (clinical, community-based samples) were included, and studies without control groups were excluded. Outcome of interest was fertility problems, e.g. inability to achieve pregnancy, live birth, neonatal death depending on study. The Newcastle-Ottawa Scale was used to assess study quality. A total of 3843 studies were identified, and 62 were included (58 in meta-analyses; n = 111,977). Results revealed the following: a ninefold risk of inability to become pregnant in genital tuberculosis (OR 8.91, 95% CI 1.89 to 42.12); an almost threefold risk in human immunodeficiency virus (OR 2.93, 95% CI 1.95 to 4.42) and bacterial vaginosis (OR 2.81, 95% CI 1.85 to 4.27); a twofold risk of tubal-factor infertility in female genital mutilation/cutting-Type II/III (OR 2.06, 95% CI 1.03 to 4.15); and postnatal mortality in consanguinity (stillbirth, OR 1.28, 95% CI 1.04 to 1.57; neonatal death, OR 1.57, 95% CI 1.22 to 2.02). It seems that risk factors affected reproductive processes through multiple pathways. Health promotion encompassing relevant health indicators could enhance prevention and early detection of fertility problems in the Global South and disproportionately affected populations. The multifactorial risk profile reinforces the need to place fertility within global health initiatives.

Consanguineous Marriage and Its Association With Genetic Disorders in Saudi Arabia: A Review

Consanguineous marriages, where spouses are related by blood, have been a longstanding practice in human history. The primary medical concern with consanguineous marriages is the increased risk of genetic disorders. When closely related individuals reproduce, there is a higher probability that both parents carry the same genetic mutation. In Arab countries, especially Saudi Arabia, the rate of consanguineous marriage is high compared with Western European and Asian countries. This high rate is directly proportionate with elevated risk of genetic disorders, including congenital heart diseases, renal diseases, and rare blood disorders. Additionally, it was noted that the rate of negative postnatal outcomes is higher in consanguineous marriages compared with the general population. These observations indicate the necessity of tackling this area and highlighting the consequences of this practice. In this review, we aim to discuss the current evidence regarding the association between consanguineous marriages and genetic disorders in Saudi Arabia.

Consanguinity and childhood acute lymphoblastic leukaemia: a case-control study

Background

Consanguineous marriage is widely practised across the world. Its effect on acute lymphoblastic leukaemia (ALL) is controversial as both parents share some of the genes which might increase the incidence of sharing recessive genes. However, other theories suggest that consanguinity might have a protective factor as it does for other types of cancers. This study aims to study childhood ALL and consanguinity.

Methods

This is a case-control study, conducted in the major paediatric hospital in Damascus, Syria, using medical records. Case group included children with ALL, while control group included other patients and were matched by gender and age.

Results

This study comprised 386 patients, 193 of which were cases. Overall, 136 were of consanguineous marriages (36.8%), and there was no difference in consanguinity overall between cases and controls. However, when only comparing non-consanguineous parents and fourth-degree consanguinity, fourth degree was significantly higher among case group, suggesting a negative correlation OR = 0.387 (0.187–0.801) in contrast to third-degree consanguinity which was no significantly different when comparing the two groups (p > 0.05). We found no significant association between ALL and having a family history of cancer (p > 0.05) or between parents’ educational level and case-control groups (p > 0.05).

Conclusion

Our research suggests a negative association between fourth-degree consanguinity and childhood leukaemia. This was not observed with a third-degree consanguinity. Previous studies had contradicting data on consanguinity and ALL which demonstrates the need for further research.

Association of Parental Consanguinity With Papillary Thyroid Carcinoma: A Case-Control Study

CONTEXT

Papillary thyroid carcinoma (PTC) is the most common type of nonmedullary thyroid carcinoma. Uncommonly, PTC is associated with multiple genetic alterations and chromosomal abnormalities and displays familial patterns of inheritance. Parental consanguinity increases susceptibility to many genetic disorders.

OBJECTIVE

This work aimed to investigate the association of parental consanguinity with PTC.

METHODS

This case-control study of PTC patients compared with healthy controls took place in a tertiary referral hospital. We recruited 200 PTC patients who were managed at the endocrinology outpatient clinics of the Jordan University Hospital, and we recruited 515 healthy controls from a nonclinical setting. We interviewed all participants and collected sociodemographic data. We reviewed the family pedigrees of each participant four generations back and excluded any participant who was related. We established whether the parents of each participant were first cousins, first cousins once removed, second cousins, or unrelated. We then used binary logistic regression to assess the association of parental consanguinity with PTC adjusted for age, sex, smoking status, body mass index, and parental education.

RESULTS

We recruited 715 participants. The numbers of PTC patients and healthy controls were 200 (28.0%) and 515 (72.0%), respectively. The rate of parental consanguinity was 25.5% in PTC patients and 12.2% in healthy controls. Parental consanguinity was significantly associated with PTC (adjusted odds ratio, 2.60; 95% CI, 1.63-4.17; P < .001).

CONCLUSION

Parental consanguinity is a risk factor for PTC. Our findings should be considered during familial risk assessment and genetic counseling, especially in populations with high rates of consanguinity.

Analyzing Inbreeding and Estimating Its Related Deficiencies in Northeastern Brazil

This cross-sectional study aimed to observe number of marriages between relatives in São Francisco Valley municipalities and correlations between degrees of kinship and susceptibility to genetic diseases. Three hundred and nine (309) consanguineous couples were interviewed in five municipalities. The data were analyzed using SPSS (version 22), Chi-square testing, and the generalized estimating equation (GEE). In Pariconha-AL for first cousins, the results revealed significantly higher numbers of disabled children than for third cousins (p < 0.05). Of these, the prevalence for physical disability was significant (χ2 = 19.203, df = 4, p = 0.001). In the cities of Glória-BA (χ2 = 11.652, df = 3, p = 0.020) and OlhoD'água do Casado-AL (χ2 = 8.123, df = 4, p = 0.044), physical disabilities were also significantly higher in children from unions of first-degree cousins than for other degrees of kinship. Visual impairment was more significant in first-degree cousins in Glória-BA (χ2 = 14.206, df = 3 p = 0.007); yet among third-degree cousins, visual impairment in the municipality of Santa Brígida-BA was more prevalent (χ2 = 6.416, df = 2 p = 0.040). Inbreeding, as revealed in the evaluated cities, reinforces the hypothesis for developing genetic diseases.

Effects of consanguinity in a cohort of subjects with certain genetic disorders in Qatar

Background

Consanguineous marriages are common in the Middle East including the Gulf countries. The rate of consanguinity in Qatar is approximately 54%, which are mainly first cousins’ marriages. Previous studies showed that consanguinity increases the prevalence of birth defects and other genetic disorders. Thus, we studied the effects of consanguinity in a cohort of subjects with certain genetic disorders in Qatar.

Methods

This cross‐sectional study was conducted at two centers in Qatar (Hamad Medical Corporation “HMC” and Shafallah “SC”) including 599 Qatari families with certain types of genetic and nongenetic anomalies.

Results

Consanguineous marriages were seen in 397 of 599 (66.2%) Qatari families and first cousin group counts for 65% in Qatari population. In the total cohort and at HMC, all consanguineous marriages had a significantly higher risk of Autosomal Recessive disorders than nonconsanguineous marriages (total cohort: odds ratio (OR) = 1.72; 95% CI: 1.10, 2.71; p = .02; HMC: OR = 2.98; 95% CI: 1.37, 6.09; p = .005). On the other hand, at HMC, nonconsanguinity was significantly related to chromosomal abnormality (OR = 6.36; 95% CI: 1.13, 35.85; p = .036).

Conclusion

Our data suggest a significant role of parental consanguinity in increasing the prevalence of genetic disorders; mainly Autosomal Recessive disorders. Chromosomal abnormality disorders were significantly higher among nonconsanguineous marriages. These results help better inform policy makers on social, educational, and public health initiatives that might mitigate the impact of genetic disease in the Qatari society.

An Interpretative Phenomenological Analysis of Families Affected by Autism in Dubai

<b><i>Background:</i></b> The prevalence of autism spectrum disorders (ASD) in the Middle East region is suggested to be comparable with rates reported in the Western World; however, in the United Arab Emirates (UAE), autism is under-diagnosed and over-looked. <b><i>Objectives:</i></b> This qualitative study based in Dubai, UAE, aimed to explore personal experiences of autism and investigate the decision-making process of parents. A focus group interview with 6 UAE national mothers who have an autistic child was conducted; the semi-structured interview was audio-recorded and transcribed. <b><i>Method:</i></b> Interpretative phenomenological analysis was performed on the interview transcript and 3 main themes emerged: Education, Support and Social Stigma. <b><i>Results:</i></b> The research concluded that the majority of mothers are primary caregivers and the challenges faced by autistic families include: a lack of understanding and research; family reputation; stigma-associated discrimination; and maternal stress. <b><i>Conclusions:</i></b> Mothers with autistic children experience a number of stressors and would benefit from educational workshops, including ASD-specific training. A call for further investigation into the role and impact of maids as primary caregivers for autistic children in the UAE is advocated.

Metabolic dysfunction in Emirati subjects in Abu Dhabi: Relationship to levels of soluble RAGEs

BACKGROUND

The United Arab Emirates is experiencing increasing rates of type 2 diabetes (T2D) and its complications. As soluble levels of the receptor for advanced glycation end products, (sRAGE), and endogenous secretory RAGE (esRAGE), the latter an alternatively spliced form of AGER (the gene encoding RAGE), have been reported to be associated with T2D and its complications, we tested for potential relationships between these factors and T2D status in Emirati subjects.

METHODS

In a case-control study, we recruited Emirati subjects with T2D and controls from the Sheikh Khalifa Medical City in Abu Dhabi. Anthropomorphic characteristics, levels of plasma sRAGE and esRAGE, and routine chemistry variables were measured.

RESULTS

Two hundred and sixteen T2D subjects and 215 control subjects (mean age, 57.4 ± 12.1 vs. 50.7 ± 15.4 years; P < 0.0001, respectively) were enrolled. Univariate analyses showed that levels of sRAGE were significantly lower in the T2D vs. control subjects (1033.9 ± 545.3 vs. 1169.2 ± 664.1 pg/ml, respectively; P = 0.02). Multivariate analyses adjusting for age, sex, systolic blood pressure, pulse, body mass index, Waist/Hip circumference ratio, fasting blood glucose, HDL, LDL, insulin, triglycerides, Vitamin D and urea levels revealed that the difference in sRAGE levels between T2D and control subjects remained statistically-significant, P = 0.03, but not after including estimated glomerular filtration rate in the model, P = 0.14. There were no significant differences in levels of esRAGE. Levels of plasma insulin were significantly higher in the control vs. the T2D subjects (133.6 ± 149.9 vs. 107.6 ± 93.3 pg/L. respectively; P = 0.01, after adjustment for age and sex).

CONCLUSION/DISCUSSION

Levels of sRAGE, but not esRAGE, were associated with T2D status in Abu Dhabi, but not after correction for eGFR. Elevated levels of plasma insulin in both control and T2D subjects suggests the presence of metabolic dysfunction, even in subjects without diabetes.

A review of the reproductive consequences of consanguinity

BACKGROUND

Consanguinity is the close union, sexual relationship or marriage between persons who have common biological ancestors usually up to about 2nd cousins. Contrary to general opinion consanguinity is quite common and is practiced worldwide. It is an important topic as while rates of consanguineous unions in certain society have decreased over time, rates have remained stable or increased in other societies with rates as high as 80.6% in some communities. Our aim was to conduct a review looking at general aspects of consanguinity and any published reproductive outcomes in literature. We also looked at possible future directions that could be relevant in the management of the consanguineous couple to help improve reproductive outcomes.

METHOD

We conducted a PUBMED, CINAHL, Web of Knowledge and Google Scholar search looking at articles on consanguinity. Consanguinity articles related to pregnancy and reproduction were searched using additional filters looking at our specific areas of interest. All relevant publications up to March 2015 were reviewed. Additional search for relevant articles pertaining to pre implantation genetic diagnosis for future directions in the management of the consanguineous couple was done. Most publications were found in books, on line articles and journals. Most were retrospective, population or cohort studies.

RESULT

Consanguinity is practiced by up to 10% of the world's population with rates ranging from 80.6% in certain provinces in the Middle East to less than 1% in western societies. It predates Islam and has been practiced since Old Testament times. The most commonly cited reason for consanguinity is sociocultural and socioeconomic although it is also more common in certain religions. In areas where rates of Consanguinity are reducing urban migration and increasing education rates are thought to be contributory. Congenital malformations have long been established to be higher in consanguineous couples above the background rate (4.5% Vs 1%).Due to "Founder effect" or a common ancestor, Consanguinity is most commonly associated with Inborn errors of metabolism most of which are autosomal recessive. Consanguinity increases the incidence of multifactorial disorders such as diabetes, cardiovascular disorders, obesity and certain types of cancers. These may in turn affect reproductive outcomes. It may also affect fertility rates. Pregnancy outcomes like increased pregnancy wastages and preterm labor have been reported with consanguinity. Other studies produced conflicting evidence on its effect regarding outcomes like hypertensive disorders of pregnancy and Intrauterine growth restriction.

CONCLUSION

Consanguinity continues to be practiced worldwide and in some countries rates are increasing. The main reason for the practice appears to be sociocultural and socioeconomic although religious beliefs is a contributory factor. The most significant effects on reproductive outcomes are mostly due to autosomal recessive inherited conditions and inborn errors of metabolism. It also significantly increases the inheritance of certain multifactorial disorders like diabetes which may indirectly affect reproductive outcomes. In the future with the completion of the study of the whole human Genome and current advances in Pre implantation Genetic diagnosis and screening it may be possible to mitigate some of the adverse reproductive outcomes associated with consanguinity.

City and cosmology: genetics, health, and urban living in Dubai

In light of increasingly high rates of diabetes, heart disease, and obesity among citizens of the Arabian Gulf, popular health discourse in the region has emphasised the emergent Arab genome as the primary etiological basis of major health conditions. However, after many years of public dissemination of genomic knowledge in the region, and widespread acceptance of this knowledge among Gulf Arab citizens, the rates of chronic illness continue to increase. This paper briefly explores the clash between indigenous Islamic knowledge systems and biomedical knowledge systems imported into the United Arab Emirates. It presents vignettes collected from interviews and participant observation in Dubai as part of nearly four years of ethnographic research, completed as part of the author's doctoral work on 'Anxiety and Identity in Southeast Arabia'. Rather than radically informing health seeking behaviours among many UAE citizens, the emphasis on the 'Arab Genome' has instead reconfirmed the authority of Bedouin cosmological understandings of disease, reshaping the language that people use to engage with their bodies and their health. Local cosmology remains a powerful discursive element that often operates in contention, in sometimes powerfully subtle ways, with novel health initiative regimes. For many people in the region, genomic information, as it is often discussed and propagated in the UAE, shares an intimate relationship with ideas of fate and national identity, and sometimes serves to mitigate the increasingly uncertain terms of engagement that people share between the body, their health, and rapidly changing urban landscapes.

Genetic polymorphisms of cytochrome P450-1A2 (CYP1A2) among Emiratis

Cytochrome P450 1A2 (CYP1A2) is one of the CYP450 mixed-function oxidase system that is of clinical importance due to the large number of drug interactions associated with its induction and inhibition. In addition, significant inter-individual differences in the elimination of drugs metabolized by CYP1A2 enzyme have been observed which are largely due to the highly polymorphic nature of CYP1A2 gene. However, there are limited studies on CYP1A2 phenotypes and CYP1A2 genotypes among Emiratis and thus this study was carried out to fill this gap. Five hundred and seventy six non-smoker Emirati subjects were asked to consume a soft drink containing caffeine (a non-toxic and reliable probe for predicting CYP1A2 phenotype) and then provide a buccal swab along with a spot urine sample. Taq-Man Real Time PCR was used to determine the CYP1A2 genotype of each individual. Phenotyping was carried out by analyzing the caffeine metabolites using High Performance Liquid Chromatography (HPLC) analysis. We found that 1.4%, 16.3% and 82.3% of the Emirati subjects were slow, intermediate and rapid CYP1A2 metabolizers, respectively. In addition, we found that 1.4% of the subjects were homozygote for derived alleles while 16.1% were heterozygote and 82.5% were homozygote for the ancestral allele. The genotype frequency of the ancestral allele, CYP1A2*1A/*1A, is the highest in this population, followed by CYP1A2 *1A/*1C and CYP1A2 *1A/*1K genotypes, with frequencies of 0.825, 0.102 and 0.058, respectively. The degree of phenotype/genotype concordance was equal to 81.6%. The CYP1A2*1C/*1C and CYP1A2*3/*3 genotypes showed significantly the lowest enzyme phenotypic activity. The frequency of slow activity CYP1A2 enzyme alleles is very low among Emiratis which correlates with the presence of low frequencies of derived alleles in CYP1A2 gene.

ASSESSMENT OF KNOWLEDGE, ATTITUDE AND PRACTICE TOWARDS CONSANGUINEOUS MARRIAGES AMONG A COHORT OF MULTIETHNIC HEALTH CARE PROVIDERS IN SAUDI ARABIA

This study aimed to assess knowledge, attitude and practice related to consanguinity among multiethnic health care providers in the Kingdom of Saudi Arabia. Using a cross-sectional study design, a validated, self-administered close-ended questionnaire was randomly distributed to health care providers in different health institutions in the country between 1st August 2012 and 31st July 2013. A total of 1235 health care providers completed the study questionnaire. Of the 892 married participants (72.23% of total), 11.43% were married to a first cousin, and were predominantly Arabs, younger than 40 years and male. Only 17.80% of the patients seen by the health care providers requested consanguinity related counselling. A knowledge barrier was expressed by 27.49% of the participants, and 85.67% indicated their willingness to have more training in basic genetic counselling. A language barrier was expressed as a limiting factor to counselling for consanguinity among non-Arabs. The health care providers had a major dearth of knowledge that was reflected in their attitude and practice towards consanguinity counselling. This finding indicates the need for more undergraduate and postgraduate medical and nursing education and training in the counselling of consanguineous couples. It is recommended that consanguinity counselling is included in the current premarital screening and counselling programmes in the Kingdom.

Consanguinity and associated perinatal outcomes, including stillbirth

BACKGROUND

Consanguinity defined as the sexual union between two related individuals has been previously an infrequent practice in Australia, but recently there has been migration from countries with widespread practice of consanguinity. There is limited and conflicting evidence in the literature that suggests consanguinity to be associated with adverse obstetric outcomes.

AIM

To assess the effect of consanguinity on perinatal outcomes.

MATERIALS AND METHODS

A retrospective analysis of singleton births over a ten-year period at an Australian tertiary hospital. The data were extracted from the hospital obstetric database and analysed for an association between consanguinity and perinatal outcomes, including stillbirth. Main outcome measures were stillbirth, threatened premature labour, fetal congenital abnormality, perinatal mortality and neonatal outcomes.

RESULTS

There were 46 399 singleton births recorded over the ten-year study period, and 44 004 had consanguinity data available. The overall consanguinity rate was 5.5% (n = 2565), which remained consistent over the study period at our institution. Consanguinity was associated with higher rate of threatened premature labour (5.6% vs 4.7%, P = 0.003), fetal congenital abnormality (4.2% vs 3.1%, P = 0.004), perinatal mortality (2.4% vs 1.0%, P < 0.001) and reduced risk of hypertension in pregnancy (5.3% vs 3.4%, P < 0.001). Consanguinity was an independent risk factor for stillbirth with a relative risk of 2.88 (P < 0.001, 95% CI 1.98, 4.18).

CONCLUSION

Women from consanguineous relationships are at higher risk of adverse perinatal outcomes, including stillbirth. Given the 5% prevalence of consanguinity in our obstetric population, these findings have significant implications for preconception counselling, obstetric care and health resource allocation.

Efficiency of allogeneic hematopoietic SCT from HLA fully-matched non-sibling relatives: a new prospect of exploiting extended family search

The best donors for hematopoietic SCT (HSCT) are fully-matched siblings. In patients without fully-matched siblings, HLA registries or cord blood banks are alternative strategies with some restrictions. Owing to the high rate of consanguineous marriage in our country, between 2006 and 2013, extended family searches were undertaken in Hematology-Oncology Research Center and Stem Cell Transplantation (HORCSCT), Tehran, Iran, in 523 HSCT candidates with parental consanguinity and no available HLA identical sibling. Fully-matched other-relative donors were found for 109 cases. We retrospectively studied the HSCT outcome in these patients. Median time to neutrophil engraftment was 13 days (range: 9-31days). In 83 patients, full chimerism and in 17 patients, mixed chimerism was achieved. Acute GvHD (aGvHD) grade II-IV appeared in 36 patients (33%). The frequency of aGvHD development in various familial subgroups was NS. Five patients expired before day+100. In the surviving 104 cases, chronic GvHD developed in 20 patients (19.2%). The distantly related subgroup had significantly a higher rate of cGvHD (P=0.04). The 2-year OS and disease-free survival (DFS) were 76.7±4.5% and 71.7±4.7%, respectively. No significant difference in OS (P=0.30) and DFS (P=0.80) was unraveled between various familial relationships. Our considerable rate of fully-matched non-sibling family members and the favorable outcome support the rationale for extended family search in regions where consanguineous marriage is widely practiced.

Arranging marriage; negotiating risk: genetics and society in Qatar

This paper considers how the globalized discourse of genetic risk in cousin marriage is shaped, informed and taken up in local moral worlds within the context of Qatar. This paper investigates the way Qataris are negotiating the discourse on genetics and risk. It is based on data from ongoing ethnographic research in Qatar and contributes to anthropological knowledge about this understudied country. Participants were ambivalent about genetic risks and often pointed to other theories of causation in relation to illness and disability. The discourse on genetic risk associated with marrying in the family was familiar, but for some participants the benefits of close marriage outweighed potential risks. Furthermore, the introduction of mandatory pre-marital screening gave participants confidence that risks were monitored and minimized.

Whole-exome analysis of foetal autopsy tissue reveals a frameshift mutation in OBSL1, consistent with a diagnosis of 3-M Syndrome

BACKGROUND

We report a consanguineous couple that has experienced three consecutive pregnancy losses following the foetal ultrasound finding of short limbs. Post-termination examination revealed no skeletal dysplasia, but some subtle proximal limb shortening in two foetuses, and a spectrum of mildly dysmorphic features. Karyotype was normal in all three foetuses (46, XX) and comparative genomic hybridization microarray analysis detected no pathogenic copy number variants.

RESULTS

Whole-exome sequencing and genome-wide homozygosity mapping revealed a previously reported frameshift mutation in the OBSL1 gene (c.1273insA p.T425nfsX40), consistent with a diagnosis of 3-M Syndrome 2 (OMIM #612921), which had not been anticipated from the clinical findings.

CONCLUSIONS

Our study provides novel insight into the early clinical manifestations of this form of 3-M syndrome, and demonstrates the utility of whole exome sequencing as a tool for prenatal diagnosis in particular when there is a family history suggestive of a recurrent set of clinical symptoms.

Perception of pregnancy related health issues among Arab women living in the United States

Ethnic minorities living in the US have lower utilization and access to prenatal care, resulting in an increased risk of adverse pregnancy outcomes. The present study examines utilization of prenatal care, perceived pregnancy related health, and perceived risk of adverse pregnancy outcomes among Arab women living in the USA cross-sectional study was conducted, consisting of a convenience sample of 170 Arab women. A structured questionnaire was administered by a face-to-face or telephone interview. Multivariable logistic regression was used to calculate adjusted Odds Ratios and 95% Confidence Intervals, controlling for potential confounders. All study participants had received prenatal care during their most recent pregnancy, and 90% had their first prenatal care visit before the 12th gestational week. The Arab women who were older (P = 0.02), those with 12 years of education or less (P = 0.002), and those who had lived in the US more than five years (P = 0.0002) were more likely to report four or more pregnancies. In addition, more than one-third of the women reported having experienced a miscarriage (35.4%), which was significantly associated with gravida status (P < 0.001). An association between perceived susceptibility for spontaneous abortion and stillbirth was also demonstrated (P < 0.0001). Although Arab women reported good coverage of prenatal care, they perceived themselves as susceptible for several pregnancy complications and adverse pregnancy outcomes. Clinical guidelines for prenatal care to Arab women should therefore focus on their high parity and likelihood of miscarriages, in an attempt to reduce their risk of adverse pregnancy outcomes.

Mental health issues of Maria I of Portugal and her sisters: the contributions of the Willis family to the development of psychiatry

Contemporary accounts credit Dr Francis Willis (1718-1807) with facilitating the recovery of King George III from his major episode of acute mania in 1788-9. Subsequently Willis was summoned to Lisbon to advise on the mental health problems of Queen Maria I. This article reports the nature of the illnesses of Maria and her two similarly affected sisters, and uses the program OPCRIT to propose diagnoses of major depressive disorders. The high prevalence of consanguinity and insanity among the Portuguese monarchy and their antecedents probably contributed to their mental health problems. The successive contributions of the Willis family from Thomas Willis (1621-75) to his grand-nephew, Francis Willis (1792-1859), are reviewed; the popular image is somewhat inaccurate and does not highlight their part in the development of psychiatry.

Consanguinity and inflammatory bowel diseases: is there a relation?

OBJECTIVE

The aim of the present study was to investigate the relation between consanguinity and inflammatory bowel diseases (IBD).

METHODS

Review of the medical records of children with a final diagnosis of IBD to determine age, sex, and type of IBD, supplemented by information on consanguinity and family history (FH) of IBD in relatives. There were 138 children, ages 1.4 to 19.3 years, and 50% were girls.

RESULTS

The prevalence of consanguinity was 50%, 53%, 39% and 60% in IBD, Crohn disease (CD), ulcerative colitis (UC), and controls, respectively. There was a significantly higher prevalence of consanguinity in controls than in patients with IBD and UC (P = 0.02 and 0.026, respectively), whereas the difference between CD patients and controls was not significant (P = 0.20). The prevalence of first cousin consanguinity was 71%, 73.2%, 61.5% and 70.5% in patients with IBD, CD, UC, and controls, respectively, indicating no significant difference between these conditions and controls (P = 0.95, P = 0.78, P = 0.33, respectively). There was no significant difference in the prevalence of consanguinity in the parents of children with or without a FH of either CD (P = 0.89) or UC (P = 0.32).

CONCLUSIONS

There is no significant relation between parental consanguinity and IBD in this population, especially when there is no FH of disease, suggesting reduced genetic susceptibility; however, further studies including larger sample size and details of FH of consanguinity and IBD in multiple generations are needed for further definitions of the role of consanguinity.

Risk factors predisposing to congenital heart defects

Introduction:

Congenital heart disease (CHD) is associated with multiple risk factors, consanguinity may be one such significant factor. The role of consanguinity in the etiology of CHD is supported by inbreeding studies, which demonstrate an autosomal recessive pattern of inheritance of some congenital heart defects. This study was done to find out the risk factors for CHD.

Methods:

A case-control study was done on pediatric patients at a tertiary care hospital, Aga Khan University Hospital, located in Karachi, Pakistan. A total of 500 patients, 250 cases and 250 controls were included in the study.

Results:

Amongst the 250 cases (i.e. those diagnosed with CHD), 122 patients (48.8%) were born of consanguineous marriages while in the controls (i.e. non-CHD) only 72 patients (28.9%) showed a consanguinity amongst parents. On multivariate analysis, consanguinity emerged as an independent risk factor for CHD; adjusted odds ratio 2.59 (95% C. I. 1.73 - 3.87). Other risk factors included low birth weight, maternal co-morbidities, family history of CHD and first born child. On the other hand, medications used by the mother during the index pregnancy, maternal age and gender of the child did not significantly increase the risk of developing CHD.

Conclusions:

Analyses of our results show that parental consanguinity, family history of CHD, maternal co-morbidities, first born child and low birth weight are independent risk factors for CHD.

Pattern of craniofacial anomalies seen in a tertiary care hospital in Saudi Arabia

BACKGROUND AND OBJECTIVE

To date, there are no published studies from Saudi Arabia on the incidence or etiology of craniofacial anomalies. This study aimed to report the patterns of craniofacial anomalies in Saudi Arabia.

DESIGN AND SETTING

Hospital-based, descriptive study conducted during 2002 to 2009 in the Cleft Lip/Palate and Craniofacial Anomalies Registry at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.

PATIENTS AND METHODS

Data was collected on craniofacial patients in the registry.

RESULTS

Of the 447 craniofacial patients (male, 242; female, 205), 109 (24.4%) had only cranial anomalies, 261 (58.4%) had only facial anomalies and 77 (17.2%) had both of these conditions. Craniosynostosis was seen in 33.3% of the total patients (81 males and 68 females). Of the 65 craniosynostosis syndromic patients, 25 (38.5%) had Apert syndrome and 18 (27.7%) had Crouzon syndrome. Among facial anomalies, 47 (19.4%) had dysmorphic features, followed by 35 (14.5%) with micrognathia. Among facial syndromes, 72 (59.0%) were observed to have Pierre-Robin sequence, 17 (13.9%) had Goldenhar syndrome and another 17 (13.9%) had Van der Woude syndrome. Cleft palate was more common in 171 (56.8%) patients as an associated deformity, followed by cleft lip with cleft palate in 99 (32.9%) and cleft lip in 23 (7.6%) patients. Of the 224 patients having other congenital anomalies, the cardiovascular system was most commonly affected, with 46 (20.5%) children diagnosed with congenital heart disease. A family history of anomalies was observed more in children born to parents of a consanguineous marriage than in those whose parents were unrelated (P=.01).

CONCLUSIONS

Additional efforts should be made towards creating awareness among the general population about these deformities in relation to consanguinity.

Identification of alkaptonuria in the general population: a United Kingdom experience describing the challenges, possible solutions and persistent barriers

Progress in research into rare diseases is challenging. This paper discusses strategies to identify individuals with the rare genetic disease alkaptonuria (AKU) within the general population. Strategies used included a questionnaire survey of general practitioners, a dedicated website and patient network contact, targeted family screening and medical conference targeting. Primary care physicians of the UK were targeted by a postal survey that involved mailing 11,151 UK GPs; the response rate was 18.2%. We have identified 75 patients in the UK with AKU by the following means: postal survey (23), targeted family screening (11), patient networks and the website (41). Targeting medical conferences (AKU, rare diseases, rheumatology, clinical biochemistry, orthopaedics, general practitioners) did not lead to new identification in the UK but helped identify overseas cases. We are now aware of 626 patients worldwide including newly identified non-UK people with AKU in the following areas: Slovakia (208), the rest of Europe (including Turkey) (79), North America (including USA and Canada) (110), and the rest of the world (154). A mechanism for identifying individuals with AKU in the general population-not just in the UK but worldwide-has been established. Knowledge of patients with AKU, both in the UK and outside, is often confined to establishing their location in a particular GP practice or association with a particular medical professional. Mere identification, however, does not always lead to full engagement for epidemiological research purposes or targeting treatment since further barriers exist.

Respiratory distress syndrome due to a novel homozygous ABCA3 mutation in a term neonate

The authors report, for the first time in the literature, a case of respiratory distress syndrome in a term baby due to homozygosity for a p.Trp308Arg/W308R substitution in the ATP-binding cassette transporter 3. The sequence was confirmed by genetic analysis of the baby and both parents. Management and long-term outcome of a patient carrying this novel genetic defect have not been reported in the literature before. Currently, lung transplant appears to be the only long-term survival option available, for which, our patient is being evaluated.

The effect of consanguinity on congenital disabilities in the Kuwaiti population

Consanguinity has been shown to increase homozygosity and to reduce genetic variation in a group, which may protect against the expression of recessive genes that can lead to genetic disorders. Consanguineous marriages are practised widely in Kuwait. The major aim of this study is to delineate the association of consanguineous marriages with congenital disabilities in different Kuwaiti population subcultures. A total of 9104 married Kuwaiti females aged 15-79 years from different backgrounds were selected at ten primary health care centres from six governorates in Kuwait. Data were collected using a questionnaire and analysed with chi-squared tests. The data indicate significant differences in the occurrence of genetic diseases in consanguineous couples' offspring (4.88%) compared with those of non-consanguineous couples (4.13%) (p<0.002). The results also show significant differences in frequencies of genetic/environmental diseases in consanguineous couples' offspring (8.59%) compared with those of non-consanguineous couples (8.23%) (p<0.005). No significant differences between the two groups regarding environmental diseases were observed. A higher frequency of genetic diseases was found in first- (6.97%; p<0.001), second- (6.78%; p<0.001) and third-cousin (6.46%; p<0.022) couples' offspring compared with those of non-consanguineous couples. The frequency of congenital disabilities in the offspring of couples from consanguineous marriages (2.9%) is higher than that in the offspring of non-consanguineous marriages (2.3%). But this difference is not significant at the 0.05 level. First-cousin marriages have the highest frequency (3.5%) of congenital disabilities compared with other kinds of marriages (2.1-2.3%). Differences across groups are significant (p<0.036). Significant differences are found for first-cousin couples in both physical (2.37; p<0.042) and mental (0.74; p<0.037) disabilities compared with non-consanguineous couples. No significant differences were observed in deafness and blindness disabilities. The data show no significant differences between second- and third-cousin and non-consanguineous couples in physical, mental or deafness and blindness disabilities. There are no significant differences in the percentages of offspring with congenital disabilities in consanguineous and non-consanguineous marriages across sub-population groups for the total of four types of congenital disability.

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.

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.

An analytic study of the trends in perinatal and neonatal mortality rates in the State of Qatar over a 30-year period (1977 to 2007): a comparative study with regional and developed countries

OBJECTIVE

This study was designed to analyze the trends and differences in perinatal and neonatal mortality rates in the State of Qatar over a period of 30 years (1977 to 2007), to examine the causes of neonatal deaths and compare them with some regional Gulf states and developed world countries.

STUDY DESIGN

This is a retrospective study conducted in the Women's Hospital, Hamad Medical Corporation, State of Qatar from 1977 to 2007.

METHOD

The study included all perinatal and neonatal deaths for the period 1977 to 2007, which were monitored through registers of the Neonatal Intensive Care Unit (NICU), Women's hospital. Cause of death was determined using information from hospital records, including discharge certificates. There is a national database in the Department of Preventive Medicine that records all deaths through death certificates. The missing information for the early years was collected from this database. All causes of deaths were classified in accordance with criteria based on the International Classification of Disease tenth revision (ICD-10).

RESULT

There was a notable peak in neonatal (14.1), early neonatal (12.5) and perinatal (24.7) mortality rates in 1977. There was a second peak in neonatal (12.1) and late neonatal (7.5) mortality rates in 2000. Over a period of three decades (1977 to 2007), there was a significant decline in mortality rates (P<0.0001). By 2007, the neonatal mortality rate had decreased from 14.1 to 5.1; the early neonatal mortality rate had a dramatic fall from 12.5 to 2.3; and perinatal mortality came down from 24.7 to 10.3. There was no notable reduction in the late neonatal mortality rate in 2007 (2.8) compared with that in 1980 (3.0). The still-birth (8), neonatal (5), early neonatal (2.3) and perinatal (10.3) mortality rates in Qatar were very close to the rates found in developed countries, but lower than the rates in Bahrain and Saudi Arabia. Similar to developed countries, prematurity was the leading cause of neonatal death in Qatar (42.6%), followed by congenital anomalies (28%).

CONCLUSION

This study revealed that there was a sharp significant decline in neonatal and perinatal mortality rates during the study period in Qatar. The stillbirth, neonatal and perinatal mortality rates in Qatar are comparable with those in some of the developed countries and were lower than those in some of the Gulf countries. The proportion of underweight live births was found constant during the study period. Prematurity was the leading cause of neonatal death, followed by congenital anomalies.

EFFECT OF INBREEDING ON WEIGHT GAIN OF OFFSPRING FROM BIRTH TO 12 MONTHS AFTER BIRTH: A STUDY FROM IRAN

Consanguinity, the marriage between relatives, has been associated with adverse child health outcomes. The objective of the present study was to assess the effect of consanguinity on offspring weight gain from birth to 12 months after birth. Data were collected on 250 consecutive live-born singleton newborns referred to a local health centre in Shiraz (Fars province, southern Iran). Collected data covered socio-demographic characteristics (such as parental age at delivery and parental education), sex, birth order, weights from birth to 12 months after birth and consanguinity of marriages of parents. Considering the low prevalence of double first cousin, first cousin once removed, second cousin, and beyond second cousin marriages, only first cousin and unrelated marriages were included in the study. The study population consisted of a total of 207 newborns (57 offspring of first cousins, 150 offspring of unrelated marriages). Based on the results of repeated measurements analysis of variance, weight gain was associated with type of marriage (p=0.018), sex of offspring (p=0.001) and paternal education (p<0.001). There was no interaction between type of marriage and sex (p=0.831). Birth weight was not affected by type of marriage (p=0.46). There was significant interaction between inbreeding and time (p=0.034). Offspring of consanguineous marriages showed lower weight gain in comparison with those of unrelated marriages during 3–12 months after birth.

Consanguinity and reproductive health among Arabs

Consanguineous marriages have been practiced since the early existence of modern humans. Until now consanguinity is widely practiced in several global communities with variable rates depending on religion, culture, and geography. Arab populations have a long tradition of consanguinity due to socio-cultural factors. Many Arab countries display some of the highest rates of consanguineous marriages in the world, and specifically first cousin marriages which may reach 25-30% of all marriages. In some countries like Qatar, Yemen, and UAE, consanguinity rates are increasing in the current generation. Research among Arabs and worldwide has indicated that consanguinity could have an effect on some reproductive health parameters such as postnatal mortality and rates of congenital malformations. The association of consanguinity with other reproductive health parameters, such as fertility and fetal wastage, is controversial. The main impact of consanguinity, however, is an increase in the rate of homozygotes for autosomal recessive genetic disorders. Worldwide, known dominant disorders are more numerous than known recessive disorders. However, data on genetic disorders in Arab populations as extracted from the Catalogue of Transmission Genetics in Arabs (CTGA) database indicate a relative abundance of recessive disorders in the region that is clearly associated with the practice of consanguinity.

Homozygosity and risk of childhood death due to invasive bacterial disease

Background

Genetic heterozygosity is increasingly being shown to be a key predictor of fitness in natural populations, both through inbreeding depression, inbred individuals having low heterozygosity, and also through chance linkage between a marker and a gene under balancing selection. One important component of fitness that is often highlighted is resistance to parasites and other pathogens. However, the significance of equivalent loci in human populations remains unclear. Consequently, we performed a case-control study of fatal invasive bacterial disease in Kenyan children using a genome-wide screen with microsatellite markers.

Methods

148 cases, comprising children aged <13 years who died of invasive bacterial disease, (variously, bacteraemia, bacterial meningitis or neonatal sepsis) and 137 age-matched, healthy children were sampled in a prospective study conducted at Kilifi District Hospital, Kenya. Samples were genotyped for 134 microsatellite markers using the ABI LD20 marker set and analysed for an association between homozygosity and mortality.

Results

At five markers homozygosity was strongly associated with mortality (odds ratio range 4.7 – 12.2) with evidence of interactions between some markers. Mortality was associated with different non-overlapping marker groups in Gram positive and Gram negative bacterial disease. Homozygosity at susceptibility markers was common (prevalence 19–49%) and, with the large effect sizes, this suggests that bacterial disease mortality may be strongly genetically determined.

Conclusion

Balanced polymorphisms appear to be more widespread in humans than previously appreciated and play a critical role in modulating susceptibility to infectious disease. The effect sizes we report, coupled with the stochasticity of exposure to pathogens suggests that infection and mortality are far from random due to a strong genetic basis.

Paternal asthma is a predictor for childhood asthma in the consanguineous families from the United Arab Emirates

Consanguinity is known to increase the burden of genetic disorders among offspring. However, the effect of consanguinity on a complex disorder like childhood asthma has not been studied previously. Therefore, we explored this relationship by studying the asthma prevalence in children between 6 and 14 years of age among the local Arab families of the United Arab Emirates (UAE) where consanguinity is known to be highly prevalent. A total of 1136 children from 295 families met our inclusion criteria. The prevalence of childhood asthma was higher among children in consanguineous families (43.3%) compared to non-consanguineous (22.6%, p < 0.001). There was a significant correlation between the degree of consanguinity and the number of asthmatic children per family (p = 0.0002). Girls from consanguineous families had proportionately more asthma (42.9%, p < 0.001) compared to boys (23.1%, p = 0.539). Paternal asthma in consanguineous families increased asthma risk for both boys and girls (p = 0.021 for boys, p < 0.001 for girls), while maternal asthma had no significant impact on asthma in offspring. Prevalence of childhood asthma was significantly higher in consanguineous families. The significant asthma predictors for girls from the consanguineous families were the degree of consanguinity and paternal asthma. The only predictor for boys was paternal asthma. These interesting observations merit further studies on both larger samples and in other consanguineous communities for confirmation.

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.

Mutations in radial spoke head protein genes RSPH9 and RSPH4A cause primary ciliary dyskinesia with central-microtubular-pair abnormalities

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous inherited disorder arising from dysmotility of motile cilia and sperm. This is associated with a variety of ultrastructural defects of the cilia and sperm axoneme that affect movement, leading to clinical consequences on respiratory-tract mucociliary clearance and lung function, fertility, and left-right body-axis determination. We performed whole-genome SNP-based linkage analysis in seven consanguineous families with PCD and central-microtubular-pair abnormalities. This identified two loci, in two families with intermittent absence of the central-pair structure (chromosome 6p21.1, Zmax 6.7) and in five families with complete absence of the central pair (chromosome 6q22.1, Zmax 7.0). Mutations were subsequently identified in two positional candidate genes, RSPH9 on chromosome 6p21.1 and RSPH4A on chromosome 6q22.1. Haplotype analysis identified a common ancestral founder effect RSPH4A mutation present in UK-Pakistani pedigrees. Both RSPH9 and RSPH4A encode protein components of the axonemal radial spoke head. In situ hybridization of murine Rsph9 shows gene expression restricted to regions containing motile cilia. Investigation of the effect of knockdown or mutations of RSPH9 orthologs in zebrafish and Chlamydomonas indicate that radial spoke head proteins are important in maintaining normal movement in motile, "9+2"-structure cilia and flagella. This effect is rescued by reintroduction of gene expression for restoration of a normal beat pattern in zebrafish. Disturbance in function of these genes was not associated with defects in left-right axis determination in humans or zebrafish.

Consanguinity in Lebanon: prevalence, distribution and determinants

The union of individuals with a common ancestor may lead to serious health consequences in their offspring. Consanguinity is high in Middle Eastern communities; it was around 26% in 1988. The objective of this study was to determine the prevalence of consanguinity in Beirut and other Lebanese regions, and its associated factors in different subgroups. The cross-sectional study was performed on a convenience sample of married women in Lebanon. The women were administered a standardized questionnaire in a face-to-face interview by independent enquirers. Among 1556 women, the overall prevalence of consanguineous marriages was 35.5%, and the consanguinity coefficient was 0.020; 968 marriages (62.2%) were not consanguineous, 492 (31.6%) were first cousin, 61 (3.9%) were second cousin and 36 (2.3%) had lower degrees of consanguinity. Beirut suburb dwelling, low education subgroups, women working in the home and non-Christian religion presented the highest rates of consanguinity (p<0.05). Consanguinity is associated with couples' nulliparity and child chronic morbidity. Factors that could affect consanguinity are having consanguineous parents, having a favourable opinion towards consanguinity, choosing a spouse for religious reasons, particularly in Islam, woman having a low education, woman working in the home and women thinking that consanguinity would not lead to serious diseases. Consanguinity is therefore still a prevailing problem in Lebanon. Specific health education, and genetic counselling in particular, are suggested to explain the consequences of consanguinity to the general population and to help couples make informed choices.

The prevalence of consanguineous marriages in an underserved area in Lebanon and its association with congenital anomalies

BACKGROUND

Consanguinity is a recognized common practice among marriages in the Middle East. Many studies have suggested a strong association between first cousin marriages and the incidence of autosomal recessive diseases and congenital anomalies. The objectives of this study were to study the prevalence of consanguinity among the marriages of Bekaa (a region in Lebanon) with its sociodemographic correlates, and to assess the prevalence of congenital anomalies associated with these marriages.

METHODS

This study was a cross-sectional study done in three of the major areas of the Bekaa region. The sample size consisted of 552 households chosen based on proportionate random sampling according to population size in each area. The survey was conducted based on face-to-face interview with a member of the couples of each household.

RESULTS

The overall prevalence of consanguineous marriages was reported to be 42% with first cousin marriage constituting around 31% of the total marriages. No association was found between different socioeconomic status (SES) correlates and first cousin marriages. Results showed a significant association between first cousin marriage and mental retardation, physical retardation, bilateral cleft lip +/- cleft palate, cystic fibrosis, and congenital blindness.

CONCLUSION

In a population with a high degree of inbreeding, the formulation of a public health program with multiapproach strategy, including education about the anticipated genetic consequences, prenatal diagnosis, neonatal screening, and genetic counseling, is a necessity.

R58fs mutation in the HGD gene in a family with alkaptonuria in the UAE

This study was conducted to determine the prevalence of alkaptonuria in the UAE population and to identify the genotype of affected individuals. In a 3 stage sampling technique 2981 pupils from Government schools in Al Ain and private schools in Dubai were selected to take part in the study, of whom 2857 provided urine samples. Urine collected was analysed for homogentisic acid by gas chromatography-mass spectrometry. Genomic DNA was isolated from the white blood cells of all family members of the affected case following standard established protocols. Specific PRC primers were designed to amplify all 14 exons of the HGD gene with the flanking intronic sequences including the splice site sequences. 2857 children returned a viable urine sample, of which one was highly positive for homogentisic acid. All 12 members of this girl's family were studied and one, a 22 year old brother, was found to excrete HGA. Another, a sister who had not provided a urine sample, was discovered by genetic testing. There were no complaints of joint pain or other symptoms in any member of this family. Parents were first cousins. We found a single nucleotide deletion c.342delA, located in exon 3, which resulted in a frameshift at amino acid position 58 (p.Arg58fs or p.R58fs). Alkaptonuria may be more common than it is thought to be with an allele prevalence estimated at 0.0107 (95% CI 0.000392-0.03473). The R58fs mutation is old, perhaps having occurred several thousand years ago, and has spread over a large geographical area.

Case reports of a new syndrome associating gingival fibromatosis and dental abnormalities in a consanguineous family

BACKGROUND

Gingival fibromatosis (GF) is characterized by fibrotic enlargement of the gingiva that can be inherited as an isolated trait (named hereditary gingival fibromatosis) or as a component of a syndrome. This article reports one kindred affected by a syndrome characterized by GF associated with dental abnormalities (DA) including generalized thin hypoplastic amelogenesis imperfecta (AI).

METHODS

To characterize the pattern of inheritance and the clinical features, 70 family members were examined. Hematoxylin and eosin staining, immunohistochemistry, and scanning electronic microscopy (SEM) were performed to identify the alterations on gingiva, teeth, and dental follicles.

RESULTS

Examination of the family pedigree demonstrated multiple consanguineous first-cousin marriages and an autosomal recessive trait of inheritance. Four members demonstrated mild GF in association with DA, including generalized thin hypoplastic AI, intrapulpal calcifications, delay of tooth eruption, and pericoronal radiolucencies involving unerupted teeth. One of those four patients also had mental retardation (MR). MR as an isolated feature was observed in six members, whereas isolated GF was found in one individual. A combination of gingivectomy and gingivoplasty followed by regular dental procedures were performed in these patients. Histologic examination of the gingival enlargement revealed a dense connective tissue containing myofibroblasts, islands of odontogenic epithelium, and calcified psammomatous deposits, which resembled cementicle-like structures by SEM. Pericoronal lesions also showed calcified psammomatous deposits in association with islands of odontogenic epithelium. Enamel ultrastructure analysis revealed normal surface alternating with irregular and porous areas.

CONCLUSION

To the best of our knowledge, these cases represent a new syndrome within the spectrum of those including GF.

Consanguinity and major genetic disorders in Saudi children: a community-based cross-sectional study

BACKGROUND AND OBJECTIVES

There is a high rate of consanguinity in Saudi Arabia; however, information on its relationship with genetic disorders is limited. The objective of this cross-sectional study was to explore the role of consanguinity in genetic disorders.

SUBJECTS AND METHODS

The study sample was determined by a multistage probability random sampling procedure. Consanguinity status was obtained during household visits. Primary care physicians performed a history and physical examination of all children and adolescents younger than 19 years, and all cases of genetic diseases were recorded. The chi-square test was used to compare proportions.

RESULTS

During the two-year study period (2004-2005), 11 554 of 11 874 (97%) mothers answered the question on consanguinity, and 6470 of 11 554 (56%) were consanguineous. There was no significant association between first-cousin consanguinity and Down syndrome (P=.55). Similarly, there was no significant association with either sickle cell disease (P=.97) or glucose-6-phosphate dehydrogenase deficiency (P=.67) for first-cousin consanguinity. A borderline statistical significance was found for major congenital malformations (P=.05). However, the most significant association with first-cousin consanguinity was congenital heart disease (CHD) (P=.01). Finally, no significant association was found for type 1 diabetes mellitus (P=.92). For all types of consanguinity, similar trends of association were found, with a definite statistically significant association only with CHD (P=.003).

CONCLUSION

The data suggest a significant role of parental consanguinity in CHD. However, a relationship between consanguinity and other genetic diseases could not be established. The effect of consanguinity on genetic diseases is not uniform and this should be taken into consideration in genetic counseling.

Does consanguinity increase the risk of bronchial asthma in children?

There is a high prevalence of consanguinity and bronchial asthma in Saudi Arabia. The objective of this study is to explore the effect of parental consanguinity on the occurrence of bronchial asthma in children. The study sample was determined by multistage random probability sampling of Saudi households. The families with at least one child with asthma were matched with an equal number of families randomly selected from a list of families with healthy children, the latter families being designated as controls. There were 103 families with children having physician-diagnosed bronchial asthma, matched with an equal number of families with no children with asthma. This resulted in 140 children with bronchial asthma and 295 children from controls. The age and gender distribution of the children with bronchial asthma and children from controls were similar. There were 54/103 (52.4%) and 61/103 (59.2%) cases of positive parental consanguinity in asthmatic children and children from controls respectively (P = 0.40). Analysis of consanguinity status of the parents of children with asthma and parents among controls indicates that 71/140 (51%) of the children with asthma and 163/295 (55.3%) of the children from controls had positive parental overall consanguinity (P = 0.43). The results of this study suggest that parental consanguinity does not increase the risk of bronchial asthma in children.

Risk of cancer in an inbred population

BACKGROUND

In spite of a high prevalence of consanguineous marriages in Asia and Africa, there has been little epidemiological research on the effect of inbreeding on cancer risk.

METHODS

We conducted a case-control study of 391 native Arabs with cancer and 378 matched healthy controls. All cases had a histologic diagnosis of cancer. Participants were interviewed to collect information on the biological relatedness of their parents. Risk of cancer was determined in relation to the presence of parental consanguinity, coefficient of inbreeding (F), and whether subjects were more (F>or=0.0625) or less (F<0.0625) inbred, and was stratified by sex, age group, and cancer type.

RESULTS

Reduction of overall cancer risk was associated with increased F (P<0.001). In men, F was significantly higher in healthy controls than cancer patients overall (P=0.001) and in both younger (<or=30 years) and older age groups (P=0.003 and 0.013, respectively). In women, reduction of overall cancer risk by increased F was found only in the older age group (P=0.03). Overall, being more inbred was associated with a reduction in overall cancer risk by about 25% (odds ratio (OR), 0.74; 95% confidence interval (CI), 0.64-0.86). For seven of the eight most common cancer types, the risk of cancer was reduced with increased F but these did not reach conventional statistical significance (P>0.05).

CONCLUSIONS

Inbreeding was associated with reduced overall risk of cancer in studied population. Reduction of cancer risk is greater in men than women and, in women, is restricted to those older than 30 years.

Genomewide linkage scan for split-hand/foot malformation with long-bone deficiency in a large Arab family identifies two novel susceptibility loci on chromosomes 1q42.2-q43 and 6q14.1

Split-hand/foot malformation with long-bone deficiency (SHFLD) is a rare, severe limb deformity characterized by tibia aplasia with or without split-hand/split-foot deformity. Identification of genetic susceptibility loci for SHFLD has been unsuccessful because of its rare incidence, variable phenotypic expression and associated anomalies, and uncertain inheritance pattern. SHFLD is usually inherited as an autosomal dominant trait with reduced penetrance, although recessive inheritance has also been postulated. We conducted a genomewide linkage analysis, using a 10K SNP array in a large consanguineous family (UR078) from the United Arab Emirates (UAE) who had disease transmission consistent with an autosomal dominant inheritance pattern. The study identified two novel SHFLD susceptibility loci at 1q42.2-q43 (nonparametric linkage [NPL] 9.8, P=.000065) and 6q14.1 (NPL 7.12, P=.000897). These results were also supported by multipoint parametric linkage analysis. Maximum multipoint LOD scores of 3.20 and 3.78 were detected for genomic locations 1q42.2-43 and 6q14.1, respectively, with the use of an autosomal dominant mode of inheritance with reduced penetrance. Haplotype analysis with informative crossovers enabled mapping of the SHFLD loci to a region of approximately 18.38 cM (8.4 Mb) between single-nucleotide polymorphisms rs1124110 and rs535043 on 1q42.2-q43 and to a region of approximately 1.96 cM (4.1 Mb) between rs623155 and rs1547251 on 6q14.1. The study identified two novel loci for the SHFLD phenotype in this UAE family.

Consanguineous marriages and their effects on common adult diseases: studies from an endogamous population

OBJECTIVES

The aim of the study was to determine the extent and nature of consanguinity in the Qatari population and its effects on common adult diseases.

SUBJECTS AND METHODS

The study was conducted in urban and semi-urban areas of Qatar between October 2004 and May 2005. The total sample of 1,050 married Qatari females 15 years of age and over were approached for study. The degree of consanguinity between each female and her spouse and the degree of consanguinity between their parents were recorded.

RESULTS

Of 1,050 married Qatari females who were approached, 876 agreed to participate in the study, giving an 83.4% response. The rate of consanguinity in the present generation was 51% (95% confidence interval = 47.7-54.4) with a coefficient of inbreeding of 0.023724. The consanguinity rate and coefficient of inbreeding in the current generation were significantly higher than the maternal rate (51.0 vs. 40.3%; p < 0.001; 0.023724 vs. 0.016410 maternal). All types of consanguineous marriages were higher in this generation, particularly first cousins (26.7 vs. 21.4% paternal and 23.1% maternal) and double first cousins (4.3 vs. 2.9% paternal and 0.8% maternal). The current generation of consanguineous parents had a slightly higher risk for most diseases: cancer, mental disorders, heart diseases, gastro-intestinal disorders, hypertension, hearing deficit and diabetes mellitus. All reported diseases were more frequent in consanguineous marriages.

CONCLUSION

The study showed that in a population 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.

Consanguineous marriage and congenital heart defects: a case-control study in the neonatal period

The independent effect of consanguinity on the prevalence of congenital heart defects (CHDs), all and specific types, was investigated in newborns admitted to nine hospitals located in Beirut, Lebanon and members of the National Collaborative Perinatal Neonatal Network (NCPNN). Cases were 173 newborns admitted to the Neonatal Intensive Care Units (NICU) of participating hospitals during the 3-year period from January 1, 2000 to December 31, 2002 and diagnosed during their hospital stay as having one or more CHD. Cases with chromosomal abnormalities were excluded. Cases with more than one CHD were assigned one principal malformation. Controls consisted of a random sample of 865 newborns without a CHD admitted to the NICU during the same period. After controlling for confounders, first cousin consanguinity remained significantly associated with an increased risk of CHD: infants born to first cousin marriages had a 1.8 times higher risk of having a CHD diagnosed at birth compared to those born to unrelated parents (95% CI: 1.1-3.1). In particular, first-cousin marriage was a significant risk factor for ventricular septal defect (VSD), atrial septal defect (ASD), hypoplastic left heart (HLH), and single ventricle (SV). No association was found with d-transposition of the great arteries, coarctation, pulmonary atresia (PA), atrioventricular septal defect (AVSD), and tetralogy of Fallot (TOF). The results of this study suggest a familial factor in the multifactorial etiology of CHDs. Additional epidemiologic and family-based genetic studies are needed to understand the complex cause of CHDs.