Race, consanguinity and social features in Birmingham babies: a basis for prospective study

Evolution of a prenatal genetic clinic-A 10-year cohort study

OBJECTIVE

To (a) evaluate the proportion of women where a unifying genetic diagnosis was obtained following assessment of an observed pattern of fetal anomalies and (b) assess trends in genetic testing in a joint fetal-medicine genetic clinic.

METHOD

Retrospective cohort study of all women attending the clinic. Outcomes included (a) indication for referral, (b) genetic test performed and (c) diagnoses obtained.

RESULTS

From 2008 to 2019, 256 patients were referred and reviewed, of which 23% (n = 59) were consanguineous. The main indication for referral was the observed pattern of fetal anomalies. Over 10 years, the number of patients reviewed increased from 11 to 35 per annum. A unifying genetic diagnosis was obtained in 43.2% (n = 79/183), the majority of which were diagnosed prenatally (50.6% [n = 40/79]). The main investigation(s) that was the ultimate diagnostic test was targeted gene panel sequencing 34.2% (n = 27/79), with this and exome sequencing becoming the dominant genetic test by 2019. Pregnancies reviewed due to an abnormal karyotype or microarray decreased as an indication for referral during the study period (21.6% [n = 16/74] 2008-2012 vs 16.5% [n = 30/182] in 2012-2019).

CONCLUSION

A prenatal genetic clinic with a structured multi-disciplinary team approach may be successful in obtaining a unifying prenatal genetic diagnosis.

Local Authority Occupational Therapy Services and Ethnic Minority Clients

An audit was conducted of all current cases on the register of a metropolitan district occupational therapy office by the physical disability team. The ethnic origin, language and religion of clients was established from the records and by direct enquiry. An analysis performed of presenting problems, service response and response times demonstrated that there were significant variations between ethnic groups in the use made of the service. No evidence was found of a systematic bias against the interests of ethnic minority groups in general, but a number of questions were raised. In particular, Asian clients were more likely to be referred by certain channels, to require major works and to waft longer for action.

The implications for service providers should be explored. There is also evidence of ethnic-specific needs. The existing literature relating to ethnicity and occupational therapy, most of which is based on the American experience, is of slight value to consideration of the needs of ethnic minority groups or service providers in the United Kingdom. Social factors, including poverty and housing conditions, affect both needs and outcomes. Future research using Improved ethnic monitoring data and the baseline Information of the 1991 census of population will enlarge the debate and permit service Improvements.

CONSANGUINITY, GENETICS AND DEFINITIONS OF KINSHIP IN THE UK PAKISTANI POPULATION

Consanguineous marriage is a controversial topic in many Western societies, with attention mainly focused on the health of immigrant communities from Asia and Africa. In the UK consanguinity is especially prevalent in the Pakistani community, which now numbers over 1.1 million. Less attention has been paid to the influence of hereditary population stratification within Pakistani communities, in particular biraderi (literally brotherhood) membership, which denotes male lineages that largely govern marriage partner choice and hence the transmission of disease genes. The various roles played by biraderi and their relationship to other socio-occupational and kinship terms, such as caste, quom and zat, are often overlooked in health-based studies. The interchangeable use of these different kinship terms without rigorous definition can create identity uncertainty and hinders inter-study comparisons. Where feasible, standardization of terminology would be both desirable and beneficial, with biraderi the preferred default term to identify specific social and genetic relationships within the Pakistani diaspora.

Controversies and considerations regarding the termination of pregnancy for foetal anomalies in Islam

Background

Approximately one-fourth of all the inhabitants on earth are Muslims. Due to unprecedented migration, physicians are often confronted with cultures other than their own that adhere to different pdigms.

Discussion

In Islam, and most religions, abortion is forbidden. Islam is considerably liberal concerning abortion, which is dependent on (i) the threat of harm to mothers, (ii) the status of the pregnancy before or after ensoulment (on the 120^th day of gestation), and (iii) the presence of foetal anomalies that are incompatible with life. Considerable variation in religious edicts exists, but most Islamic scholars agree that the termination of a pregnancy for foetal anomalies is allowed before ensoulment, after which abortion becomes totally forbidden, even in the presence of foetal abnormalities; the exception being a risk to the mother’s life or confirmed intrauterine death.

Summary

The authors urge Muslim law makers to also consider abortion post ensoulment if it is certain that the malformed foetus will decease soon after birth or will be severely malformed and physically and mentally incapacitated after birth to avoid substantial hardship that may continue for years for mothers and family members. The authors recommend that an institutional committee governed and monitored by a national committee make decisions pertaining to abortion to ensure that ethics are preserved and mistakes are prevented. Anomalous foetuses must be detected at the earliest possible time to enable an appropriate medical intervention prior to the 120^th day.

Fraser syndrome: epidemiological study in a European population

Fraser syndrome is a rare autosomal recessive disorder characterized by cryptophthalmos, cutaneous syndactyly, laryngeal, and urogenital malformations. We present a population-based epidemiological study using data provided by the European Surveillance of Congenital Anomalies (EUROCAT) network of birth defect registries. Between January 1990 and December 2008, we identified 26 cases of Fraser syndrome in the monitored population of 12,886,464 births (minimal estimated prevalence of 0.20 per 100,000 or 1:495,633 births). Most cases (18/26; 69%) were registered in the western part of Europe, where the mean prevalence is 1 in 230,695 births, compared to the prevalence 1 in 1,091,175 for the rest of Europe (P = 0.0003). Consanguinity was present in 7/26 (27%) families. Ten (38%) cases were liveborn, 14 (54%) pregnancies were terminated following prenatal detection of a serious anomaly, and 2 (8%) were stillborn. Eye anomalies were found in 20/24 (83%), syndactyly in 14/24 (58%), and laryngeal anomalies in 5/24 (21%) patients. Ambiguous genitalia were observed in 3/24 (13%) cases. Bilateral renal agenesis was present in 12/24 (50%) and unilateral in 4/24 (17%) cases. The frequency of anorectal anomalies was particularly high (42%). Most cases of Fraser syndrome (85%) are suspected prenatally, often due to the presence of the association of renal agenesis and cryptophthalmos. In the European population, a high proportion (82%) of pregnancies is terminated, thus reducing the live birth prevalence to a third of the total prevalence rate.

Prenatal genetic counseling and consanguinity

OBJECTIVES

To evaluate the prevalence of consanguineous patients at a Western European prenatal genetic counseling clinic and to describe demographic as well as health-related characteristics of this patient group.

METHOD

Retrospective analysis of 1964 primary consultations at the Prenatal Genetic Counseling Outpatient Clinic at the Medical University of Vienna General Hospital in Austria. Characteristics of consanguineous patients were compared with those of a control group of not-related unions.

RESULTS

A total of 8.9% (174/1964) of all patients lived in a consanguineous union, meaning they were related as second cousin or closer [78.7% (137/174) first cousin, 14.4% (25/174) second cousin, 6.3% (11/174) first cousin once removed or 0.6% (1/174) uncle/niece]. Consanguineous patients were significantly younger (26.6 ± 5.4 vs 30.4 ± 6.5, p < 0.01) and of non-Austrian background [92.5% (161/174) vs 32.8% (57/174), p < 0.01] than not-related controls. Forty-six per cent (80/174) were referred during an ongoing pregnancy. The main counseling issue was family history of consanguinity (ICD Z84.3) in 31.6% (55/174) of cases.

CONCLUSIONS

Estimations of the prevalence of consanguinity among the general population in Western Europe likely highly underestimate the evaluated prevalence among patients referred for prenatal genetic counseling. Counseling strategies need to take into consideration that consanguineous patients are more likely to be young and have an immigrant background.

Social deprivation, ethnicity, and uptake of living kidney donor transplantation in the United Kingdom

BACKGROUND

Socioeconomic disparities and their contribution to the ethnic differences in living kidney donor transplantation have not been adequately studied.

METHODS

A total of 12,282 patients aged 18 to 69 years starting renal replacement therapy (January 1, 1997, to December 31, 2004) in the United Kingdom were included. Logistic regression models were used to examine probability of living donor transplantation within 3 years of renal replacement therapy. The effect of area deprivation (Townsend index) was studied among whites only adjusted for patient characteristics and the effect of ethnic origin (South Asians and blacks compared with whites) was then examined among all patients adjusting for area deprivation.

RESULTS

Among whites, increasing social deprivation was associated with lower odds of living donor transplantation. In the fully adjusted model, odds ratio (OR) for the most deprived quintile was 0.40 (95% confidence interval [CI] 0.33, 0.49; P trend<0.0001) compared with the least deprived. These gradients were more pronounced among centers performing more live donor transplants (P value for interaction <0.0001). South Asians and blacks had lower odds of living donor transplantation compared with whites, but there was an interaction with age (P<0.0001), so that this disparity was observed only in those younger than 50 years (blacks: OR, 0.31; 95% CI, 0.18, 0.54; South Asians: OR, 0.55; 95% CI, 0.34, 0.90; P value <0.0001).

CONCLUSIONS

Socially deprived and younger ethnic minority patients have lower probability of living kidney donor transplantation. The extent to which these inequalities reflect modifiable societal healthcare system barriers and donor/recipient factors requires further study.

Falling prevalence of beta-thalassaemia and eradication of malaria in the Maldives

Carriers of haemoglobin disorders have protection against falciparum malaria. Therefore, where this is common, carrier prevalence rises until this selective advantage is offset by deaths of affected children. Theory predicts a corresponding fall in carrier frequency following malaria eradication, but this has not been reported in practice. In the Maldives, malaria eradication (in 1972-1975) unmasked highly prevalent beta-thalassaemia and led to services for patient care and outreach carrier screening. Analysis of 68,986 laboratory screening records for subjects born between 1960 and 1990 showed carrier prevalences ranging from 10.1% to 28.2% by atoll (related to the prevalence of falciparum malaria before eradication) and a steady fall in average carrier prevalence from 21.3% among those born in 1970 to 16% in those born in 1989. Data for individuals born before 1970 suggest that earlier, when malaria was uncontrolled, carrier prevalence was 23-25%. The observed fall in carrier prevalence was broadly consistent with a model based on genetic theory, allowing for the heterogeneous distribution of carrier prevalence and the potential contribution of consanguineous marriage. The possible effects of population mixing and reproductive compensation were calculated, and any contribution to falling carrier prevalence was excluded. It is concluded that the observed fall in thalassaemia carrier prevalence in the Maldives is consistent with the predicted effect of malaria eradication and supportive of the population genetic theory. The observed fall in average carrier prevalence corresponds to a fall in minimum affected birth prevalence from approximately 12/1,000 in 1970 to approximately 6.9/1,000 in 2007. Allowing for this effect, the National Thalassaemia Register has documented a more than 60% fall in affected birth prevalence since outreach population screening was established in 1997. The main contributing factors are considered to be limitation of final family size by informed at-risk couples and utilisation of prenatal diagnosis.

The missing element: consanguinity as a component of genetic risk assessment

PURPOSE

There are no clinical practice data regarding collecting information on consanguinity as part of family history, despite its relevance for identifying at-risk pregnancies. We determined current practice and influencing factors in documenting consanguinity as part of pregnancy assessment by midwives, key health professionals in socialized medicine.

METHODS

Data were gathered from midwives in Victoria, Australia, which contains an ethnically heterogeneous population. Current practice and issues influencing practice including frequency of enquiry and attitudes regarding collecting consanguinity and family history information were documented.

RESULTS

Family history is collected by midwives, but is restricted to medical information only. Although 65.1% of midwives collect family history, only 6.4% ask about consanguinity. Direct questioning about consanguinity was seen to be difficult, reflecting social taboos, with discussion usually prompted by patient disclosure. The factor significantly associated with clinical practice in multivariate analysis was midwives' lack of confidence (adjusted odds ratio: 5.3 [95% confidence interval 1.3-22.1]) in discussing consanguinity.

CONCLUSIONS

Organizational and social barriers prevent collecting information about consanguinity in midwifery practice, restricting identification of at-risk pregnancies. Change theory is applied to inform strategies to enhance the identification of consanguineous couples.

An epidemiological study of holoprosencephaly from a regional congenital anomaly register: 1995–2004

BACKGROUND

Adequate contemporary information to counsel patients with a prenatal diagnosis of holoprosencephaly is lacking. We addressed this using data from the West Midlands Congenital Anomaly Register (WMCAR), a population-based malformation register, during a time where technological improvements have been stable and anomaly screening is well established.

METHODS

Cases were defined using the ICD 10 code for holoprosencephaly. Cases of livebirths, stillbirths and termination at all gestations were included in the study. The diagnosis was verified by a pathology or definitive radiological report with cross validation from the regional pathology, clinical genetics, cytogenetics and fetal medicine databases.

RESULTS

There were 113 cases reported of holoprosencephaly for the years 1995-2004. This represents a prevalence of 1.7 per 10,000 births and terminations, with no change in prevalence over time. There was a decreased risk of holoprosencephaly in the white population [white vs. nonwhite; RR 0.53(0.36-0.79)]. Karyotypical abnormality was noted in 46% of cases where the karyotype was known. Trisomy 13 was the most common chromosomal abnormality. Correct allocation of a diagnosis of holoprosencephaly by ultrasound occurred in 77% of cases, with another 12% having a severe intracranial abnormality but was not reported as holoprosencephaly. In 4%, a prenatal diagnosis of holoprosencephaly was not made. Termination of pregnancy was performed in 80% of all cases.

CONCLUSION

Holoprosencephaly is a morbid condition associated with significant secondary etiologies.

Population stratification and genetic association studies in South Asia

Population stratification and its influence on genetic association studies is a controversial topic. Although it has been suggested that stratification is unlikely to bias the results of association studies conducted in developed countries, convincing contrary empirical evidence has been published. However, it is in populations where historical ethnic, religious and language barriers exist that community subdivisions will predictably exert greatest genetic effect, and influence the organization of association studies. In many of the populations of the Indian sub-continent, these basic population divisions are compounded by a strict tradition of intra-community marriage and by marriage between close biological relatives. Data on the very significant levels of genetic diversity that characterize the populations of India and Pakistan, with some 50,000-60,000 caste and non-caste communities in India, and average first cousin marriage rates of 40%-50% in Pakistan, are presented and discussed. Under these circumstances, failure to explicitly control for caste/biraderi membership and the presence of consanguinity could seriously jeopardize, and may totally invalidate, the results of association/case control studies and clinical trials.

Consanguinity and Associated Socio-Demographic Factors in Qatari Population

A multi-stage sampling design was used between January and May 2004 to explore the association between sociodemographic factors and consanguineous marriages in the Qatari population using a sample of 1800 Qatari females aged 15 years and above. Data on 1515 (85.8%) Qatari national families who gave their consent for the study were obtained. The socio-demographic factors considered were: husband's age, her own age, husband's and own educational levels, husband's occupationher own occupation, housing conditions, husband's parental kinship, her own parental kinship and kinship between the spouses. The rate of consanguineous marriages in the sample was found to be 54% with 95% estimated population confidence limits 52.4% to 55.6%. Consanguinity was more common for women with educated husbands (secondary or university / high) and the frequency of consanguineous marriage significantly increased when the husband's educational level was higher (p = 0.003). The results of stepwise multiple logistic regression analysis for the occurrence of consanguineous marriages showed that the wife's education, the husband's education and parents’ consanguinity status were the only significant associated variables.

Changing profile of couples seeking genetic counseling for consanguinity in Australia

Consanguineous marriage is rare in most Western countries and, for example, in the USA it may be subject to regulation by both civil legislation and religious prescription. This is not the case in many regions of Asia and Africa where marriage within the family is strongly favored. Since the 1970s there has been widespread migration to North America, Western Europe, and Australasia from communities which encourage consanguineous marriage. To assess the effect of this trend on a genetic counseling program, the records of 302 couples referred to Genetic Services of Western Australia for consanguinity counseling were abstracted for the period 1975-2001. Overall, a family history of genetic disease or a previously affected child was reported in 28.8% of cases. Premarital or prepregnancy counseling on grounds of consanguinity was sought by 41.0% of couples, and a further 18.2% of consanguineous couples had been referred because of a consanguineous pregnancy. In 7.6% of cases a relationship closer than first cousin was involved. Through time there was a significant increase in the numbers of consanguineous consultants, and their patterns of religious affiliation and ethnic origin widened markedly. Although effectively excluded from entry to Australia prior to 1975, couples of Asian origin accounted for 25.5% of all consanguineous consultants. With ongoing migration, changes in the ethnic profiles and the specific counseling requirements of consanguineous couples can be expected to continue and probably accelerate.

Influence of ethnic origin on the incidence of keratoconus and associated atopic disease in Asians and white patients

PURPOSE

To investigate the influence of ethnic origin on the incidence of keratoconus and the association of atopic diseases in patients with keratoconus.

METHODS

Retrospective study of new patients referred to Dewsbury District General Hospital and diagnosed with keratoconus in a 6-year period between 1994 and 2000. The ethnic origin of the patient was defined as white, Asian, or other. Incidence was calculated from the catchment population of 176 774 (82% white people, 17% Asians, 1% others). t-Test, confidence intervals and chi2 tests were used to show statistical significance.

RESULTS

A total of 74 cases of keratoconus were diagnosed over this period. Of these patients 29 (39%) were white and 45 (61%) were Asian. This equated to an incidence of keratoconus of 25 per 100 000 (1 in 4000) per year for Asians, compared with 3.3 per 100 000 (1 in 30 000) per year for white people (P<0.001). Asians presented significantly younger than white patients. The incidence of atopic disease was found to be significantly higher in white compared to Asian keratoconic patients.

CONCLUSIONS

Asians were significantly more likely to present with keratoconus. The Asian patients were mostly of Northern Pakistani origin. This community has a tradition of consanguineous, especially first-cousin marriages. The higher incidence in this population was highly suggestive of a genetic factor being significant in the aetiology. The incidence was higher than revealed by previous studies. Atopic disease was significantly less common in Asians compared to white people, supporting the theory of a different aetiology in these patients.

Congenital heart disease and associated malformations in children with cleft lip and palate in Pakistan

Children with cleft lip and palate often have other associated malformations. The reported incidence and types of associated malformations vary between different studies. There is a great paucity of literature on the subject from the region in general and none from Pakistan at all. The purpose of this study was to assess the frequency of associated malformations, particularly congenital heart disease, in children with cleft lip and palate presenting to the Aga Khan University (AKU) and Murshid Hospital (MH). From 1st October 1999 to 31st March 2002, all children with cleft lip and palate who presented to AKU and MH were prospectively enrolled in the study group. Socio-demographic characteristics and a number of other variables were documented. All children underwent a thorough clinical examination and an echocardiogram as part of the study protocol. 123 children formed the study group. Thirty-five (29%) of these children were found to have associated malformations. The most common of these was congenital heart disease, which accounted for 51% of all associated malformations. Thirty percent of cleft palate children had associated anomalies while 27% of cleft lip, with or without cleft palate, children had associated anomalies. There was a significant association between children born of a consanguineous marriage and the risk of associated malformations (p-value: 0.001). Consanguinity was present in 74% of children with associated anomalies as compared to 40% of children with no associated anomaly. Dysmorphic features and the presence of associated anomalies were also significantly associated (p-value: 0.009). Dysmorphic features were present in 46% of children with anomalies as compared to 21% of children with no associated anomaly. Fifty percent of children with associated anomalies had a low birth weight compared to 34% of children with no anomalies, but the difference was not statistically significant. The presence of consanguinity in a child with dysmorphic features should raise the suspicion of an associated anomaly. The likelihood of this being a cardiac defect is high and should be ruled out with a thorough clinical examination, supplemented with an echocardiogram in certain cases.

Parental consanguinity and congenital heart malformations in a developing country

The association between isolated congenital heart defects and consanguinity was examined in 759 Lebanese patients with different types of congenital heart malformations. The subjects were patients of the Children's Cardiac Registry Center (CCRC) at the American University of Beirut Medical Center. The proportion of first-cousin marriages among cardiac subjects was compared to that of the National Collaborative Perinatal Neonatal Network (NCPNN), after adjusting for the subjects' geographic distribution, and to the highest proportion reported by NCPNN. In general, the proportion of overall parental consanguinity and first-cousin matings among CCRC subjects (34.7 and 20.2%, respectively) were significantly higher than the highest proportion of first-cousin marriages reported by NCPNN (Bekaa subjects; 13.2%) (P < 0.0001). Comparison with the NCPNN-adjusted first-cousin mating proportion revealed a significantly increased rate of consanguinity in all categories of cardiac malformations except great vessel and coronary artery lesions (P < 0.05). The following lesions were significantly associated with increased parental consanguinity: aortic anomalies (aortic insufficiency, aortic stenosis, bicuspid aortic valve), atrial septal defect, double-outlet right ventricle, pulmonary atresia, patent ductus arteriosus, pulmonic stenosis, tetralogy of Fallot, and ventricular septal defect (P < 0.05). Higher maternal education was the only variable that was negatively correlated with parental consanguinity (P = 0.037). Our study emphasizes the role of homozygous recessive genes in the causation of different types of isolated congenital heart malformations, known to follow a multifactorial pattern of inheritance. There is an urgent need for educating the public on the deleterious effects of inbreeding, especially in developing countries with high overall consanguinity rates and limited financial resources.

An insight into recent consanguinity within the Basque area in Spain. Effects of autochthony, industrialization and demographic changes

BACKGROUND

The importance of studying the genetic kinship of those human groups characterized by a deeply rooted ethnicity has traditionally been and still is an interesting goal of anthropological and population genetic studies. However, only a few surveys have aimed to learn about the impact of industrial development on the consanguinity of these populations and even those have concentrated on industrialized regions. This approach is worth analysing in Spain, where industrialization was late in relation to other western European countries.

AIM

In this work we analyse the characteristics of inbreeding in Guipúzcoa from 1951 to 1995. This Basque province underwent industrial and tourist development earlier than other Spanish regions. It has the highest density of Basque speakers and has always occupied a central position within the map of distribution of the Basque language. Guipúzcoa is geographically placed in the core of the Basque area. SUDJECTS AND METHODS: Data on consanguineous marriages recorded in the province of Guipúzcoa between 1951 and 1995 were taken from Roman Catholic dispensations stored in the Diocesan Archives of San Sebastián, the province's capital city. Over the whole time period, a total of 1152 consanguineous marriages were registered.

RESULTS

The high frequencies of first cousin (M22) (F = 1/16) and uncle-niece, aunt-nephew (M12) (F = 1/8) consanguineous marriages distinguish Guipúzcoa from the rest of Iberian populations. The M22/M33 ratio (with M33 being second cousins) has never dropped below 0.67, which represents a significant deviation from the expectation value of 0.25. When consanguineous marriages are classified according to marriage partner birthplaces interesting results emerge. Provincial endogamy shows the highest consanguinity rates (57%) and the proportion of M22/M33 is also rather high (0.63). However, a major contribution to the consanguinity levels and mean inbreeding coefficient recorded in Guipúzcoa over recent decades has been made by immigrant relative groups coming from other geographical areas of Spain. In this segment of population the observed M22/M33 rates are 1.44.

CONCLUSIONS

This study shows again how important preferentiality (or avoidance) is in human consanguinity, and also how human groups, in spite of being spatially settled in the same territory, present differential attitudes for given consanguinity patterns.

Consanguinity and its relevance to clinical genetics

Marriage between close biological relatives is generally regarded with suspicion and distaste within Western society, reflecting historical and religious prejudice. By comparison, in many other populations there is a strong preference for consanguineous unions, most frequently contracted between first cousins, and marriage outside the family is perceived as a risky and disruptive option. The increasing importance of the genetic contribution to the overall disease profile in both developed and developing countries has highlighted potential problems associated with detrimental recessive gene expression in consanguineous progeny. This review examines the outcomes of consanguineous unions, with proposals as to how the ongoing preference for consanguinity in many communities can best be accommodated from a clinical genetics perspective.

A study of possible deleterious effects of consanguinity

The aim of the study was to determine whether consanguineous marriages result in reproductive wastage and an increased incidence of illness in the offspring in a community with a long history of inbreeding and an expected high rate of consanguineous marriage. A representative sample of 2200 women aged > or = 15 years from Dubai and Al Ain, two cities in the United Arab Emirates, representing on the one hand a modern metropolis and on the other a traditional society, were studied. A questionnaire, which included questions on age, parity, gravidity, number of stillbirths, number of abortions, number of children alive, neonatal deaths and specific illnesses in children, was administered by nurses in antenatal and gynaecological clinics in the two cities. The rate of consanguineous marriage was 50.5% and parity, gravidity, ages and number of children were similar in consanguineous and non-consanguineous groups. There was no significant difference in rates of abortion, stillbirth and neonatal death between the two groups. Overall, there was statistically significant higher reproductive wastage in consanguineous couples, but when the category of less than second cousins was excluded from the consanguineous group no difference was found in reproductive wastage between consanguineous and non-consanguineous marriages. Children born to consanguineous unions also had significantly higher incidences of illnesses (37.1%) than those of non-consanguineous unions (29%). The occurrence of malignancies, congenital abnormalities, mental retardation and physical handicap was significantly higher in offspring of consanguineous than non-consanguineous marriages. In conclusion, consanguinity did not result in reproductive wastage, but was found to be an important factor in the causation of specific illnesses in offspring.

Cancer and congenital abnormalities in Asian children: a population-based study from the West Midlands

Cancer and associated congenital abnormalities were investigated in Muslim and non-Muslim Asian children from the West Midlands. Cancer incidence rates were calculated for Indian (non-Muslim), Pakistani/Bangladeshi (Muslim) and white children diagnosed from 1978 to 1992. Incidence was significantly higher in the Pakistanis, with an age-standardised rate (ASR) of 163 cases per million per year, compared with 115 for Indian and 125 for white children. Among Asian cancer patients, congenital malformations were significantly more common in Muslim (21%) compared with non-Muslim (7%). In Muslims the malformation excess was caused by autosomal recessive and dominant disorders (in 8% and 5% of cases respectively). Cancer malformation/predisposition syndromes were found in 10% of Muslims, compared with 2% of non-Muslims. In 33% of the Muslims with malformations, childhood cancer and a malformation were also present in a close relative. None of the non-Muslims with malformations had a relative with childhood cancer. The cancer excess in Muslims may be partly related to inherited genes causing both malformations and cancer. The prevalence of autosomal recessive disorders may be related to consanguinity, which is common in the Pakistani Muslim population. The high incidence of autosomal dominant disorders may be related to older paternal age at conception, giving rise to spontaneous mutations.

Birth prevalence of malformations in members of different ethnic groups and in the offspring of matings between them, in Birmingham, England

STUDY OBJECTIVES

The aims were: (1) to compare the birth prevalence of malformations in different ethnic groups and (2) to explore the reasons for the ethnic variations found by examining birth prevalence in the offspring of matings between ethnic groups.

DESIGN

Analysis of data from a register of malformations and register of births.

SETTING

Birmingham, England.

SUBJECTS

A total of 432,778 infants (including stillbirths) born in 1960-84.

MAIN RESULTS

Significant differences (p < 0.01) between ethnic groups were exhibited by the birth prevalence of neural tube defects (NTD), cleft palate, cleft lip, oesophageal atresia/fistula, hypospadias, hip dislocation, clubfoot, polydactyly, and syndactyly. In the offspring of matings between parents of European and Caribbean origin, the birth prevalence of NTD, cleft lip, hypospadias, hip dislocation, polydactyly, and syndactyly seemed more likely to be influenced by the ethnicity of both parents than by that of the mother alone. The reverse was true for the birth prevalence of NTD in subjects with one parent of Irish origin and on of British.

CONCLUSIONS

Genetic differences may be responsible for Europeans being at lower risk of polydactyly and at higher risk of NTD, cleft lip, hypospadias, hip dislocation, and syndactyly than Caribbeans. Variations in the intrauterine environment are more likely to account for NTD being more common in Irish than in British subjects.

Influence of ethnic origin on the pattern of congenital heart defects in the first year of life

OBJECTIVE

To assess the prevalence and patterns of congenital heart defects in infants requiring hospital admission in a defined population and to determine the differences in ethnic groups.

DESIGN

A three year retrospective analysis of all hospital admissions for paediatric congenital heart defects in a single centre.

SETTING

Tertiary referral centre for infant cardiac services in the West Midlands region, United Kingdom.

PATIENTS AND METHODS

Indian, Pakistani, Bangladeshi and other individuals from the Indian subcontinent constitute 5.8% of the total population of the West Midlands region. Some 9% of infants, however, are Asian because of a high birth rate. All infants with confirmed congenital heart defects resident in this region who required hospital admission between April 1990 and March 1993 were classified as Asians and non-Asian, mainly white, infants.

RESULTS

Of 1111 infants with congenital heart defects born in the West Midlands and admitted to the hospital, 17.0% were Asian, significantly more than the percentage of Asian infants in the population (P < 0.0001). Asian infants had a higher proportion of complex congenital heart disease (7% v 2.1%, P < 0.001), whereas coarctation of the aorta was more common in non-Asian (3% v 9.1%, P = 0.003). Persistent arterial duct seemed to be more common in Asian children (16% v 10%, NS), but this group included preterm infants admitted for duct ligation. There was no significant difference between the two groups in the other nine categories of congenital heart defects.

CONCLUSIONS

The estimated prevalence of congenital heart defects requiring hospital admission was higher in Asian infants than in non-Asian (9.45 per 1000 v 4.56 per 1000, P < 0.0001). Complex congenital heart defects were more common in Asian infants whereas coarctation of the aorta was more common in non-Asian.

Cystic fibrosis in children from ethnic minorities in the West Midlands

BACKGROUND

We have observed that Doctors often perceive that cystic fibrosis (CF) is exceptionally rare in non-whites, and that this bias has repeatedly resulted in diagnostic delay. We therefore compared the age at diagnosis, genetic features and relative prevalence of CF in non-whites and white patients in the West Midlands.

METHODS

Analysis of data on all CF patients diagnosed in childhood and stored in the West Midlands CF register.

RESULTS

Sixteen of the 514 children on the register were not of white European extraction, comprising 13 patients whose families originated from the Indian subcontinent, two of mixed AfroCaribbean/white European extraction and one of mixed Pakistani/white European extraction. The median age of diagnosis was similar in the white European and non-white patients (0.42 vs. 0.33 years, 95% CI for the difference of the medians -0.15, 0.37). However, in five cases with typical clinical features the diagnosis appears to have been delayed because of the child's racial origin (median age of diagnosis 3.87 years), and in five others the diagnosis was obvious (two siblings with CF, three had meconium ileus). There was a degree of consanguinity in nine cases. Five patients were homozygous or heterozygous for the delta F508 mutation, but no mutation could be identified in the remaining 11 patients.

CONCLUSIONS

The possibility of CF needs to be considered in any patient with relevant clinical problems, regardless of racial origin. These findings need to be considered when planning any mass population screening programme for CF.

Early child health in Lahore, Pakistan: II. Inbreeding

The prevalence of consanguineous marriages was studied in 940 families belonging to four different socio-economic groups in and around Lahore, Pakistan. The births occurring in these families from September 1984 to March 1987 were also investigated for birth defects. The overall prevalence of consanguineous marriages was 46%. The first cousin marriages were most common (67%), followed by the marriages between second cousins, 19%. The prevalence of consanguineous marriages was clearly associated with the socio-economic status of the study groups; 50% of the marriages was related in the periurban slum, 49% in the village, 44% in the urban slum and 31% in the upper middle class. The birth defects were also more prevalent in the poorer areas, being highest in the periurban slum (17.7%) followed by the urban slum (15.6%) and then the village (14.8%) and lowest in the upper middle class (12.3%). Although, the frequency of both consanguinity and birth defects were related with the socio-economic levels of the study groups, there was no association between inbreeding and birth defects. Perhaps, deleterious recessive genes for birth defects have been "bred out", because of continuous inbreeding over generations in this population. There was a significant predilection of major birth defects in boys without clear sex linkage. The conclusion is that the rate of consanguineous marriages was high, especially in the poorer areas, but the relationship between consanguineous marriages and birth defects was little or none. However, other child health indicators may be affected by consanguineous marriages.

Estimating inbreeding from the Faculty Office Registers, 1534-1540

Estimates of inbreeding are rather scarce for British populations. A number of studies, especially of Scottish island populations, have focused on pedigree analysis, whilst others have used survey methods or inference from isonymy. By comparison with continental Europe, however, little is known of the historical development of inbreeding. This is undoubtedly due to the lack of evidence from dispensations to marry blood relatives, which are routinely available in the records of marriage of the Roman Catholic church. The paper uses as its data source the Faculty Office Registers, 1534-1540, which were the product of a new system of issuing dispensations following the Dispensations Act of 1533, and which are among the earliest administrative records of the Church of England, founded as a result of Henry VIII's breach with Rome. Dispensations are recorded in the Faculty Office until 1540, when all prohibitions on marriage beyond the proscribed relationships laid down in Leviticus were lifted. The data suggest surprisingly low levels of consanguineous marriage, including a lack of first-cousin marriages. These findings are discussed in terms of the reliability of the archive, and of the social and religious views attending marriage between blood relatives in the medieval and early modern periods.

Racial distribution of Duchenne muscular dystrophy in the West Midlands region of Britain

In the West Midlands region of Britain, Duchenne muscular dystrophy (DMD) is twice as common as expected in Indians, and is less common than expected in Pakistanis. Although the numbers are small, they cannot be explained by any bias of ascertainment and are considered to be real. One possible mechanism for the high frequency of DMD in Indians is the presence of repetitive elements in the wild type gene which predispose to mutations.

A reconsideration of the factors affecting birth outcome in Pakistani Muslim families in Britain

Over recent years, Bradford has had a consistently high perinatal mortality rate (PNMR), especially amongst its Asian population, 66% of whom originate from Pakistan. There is a high incidence of consanguineous marriages reported among Pakistani and Muslim couples. Often, this observation is used to explain their higher PNMR and congenital malformation rates. The factors affecting birth outcome in Pakistani women are complex and interrelated. Socioeconomic, genetic, biological and environmental factors all contribute to adverse birth outcome. In addition, these are complicated by discrimination, communication barriers and culture blaming. The aim of this paper is to challenge midwives and other health professionals to reconsider the overwhelming emphasis placed on consanguinity as a factor affecting birth outcome, and to recognise the impact and interplay of other confounding variables.

Consanguinity, gestational period and anthropometric measurements at birth in Pakistan

The effects of consanguinity on gestational period and anthropometric measurements at birth were assessed in a group of 662 babies delivered in Lahore, Pakistan. Regression analysis revealed consanguinity-related declines in birthweight, recumbent length, head circumference and chest girth and in gestational period. Considered in combination with a recent report from the region linking inbreeding effects to neonatal and childhood mortality, the data suggest that the widely favoured practice among Pakistanis, at home and abroad, of marriage between close relatives may be a contributory factor in their comparatively unfavourable health profile.

Reproductive behavior and health in consanguineous marriages

In many regions of Asia and Africa, consanguineous marriages currently account for approximately 20 to 50% of all unions, and preliminary observations indicate that migrants from these areas continue to contract marriages with close relatives when resident in North America and Western Europe. Consanguinity is associated with increased gross fertility, due at least in part to younger maternal age at first livebirth. Morbidity and mortality also may be elevated, resulting in comparable numbers of surviving offspring in consanguineous and nonconsanguineous families. With advances in medicine and public health, genetic disorders will account for an increased proportion of disease worldwide. Predictably, this burden will fall more heavily on countries and communities in which consanguinity is strongly favored, as the result of the expression of deleterious recessive genes. However, studies conducted in such populations indicate that the adverse effects associated with inbreeding are experienced by a minority of families.

Why do UK-born Pakistani babies have high perinatal and neonatal mortality rates?

A prospective study of 4934 babies of different ethnic groups has confirmed the high perinatal mortality rate for Pakistanis and has shown that this was not due to a reluctance to terminate a fetus who is known to be seriously malformed. The major cause of early mortality was a high rate of lethal malformations, which occurred in about 1 in 100 Pakistani babies and which accounted for about half of their perinatal mortality. Many of these were autosomal recessive and occurred only in the offspring of consanguineous parents. However, there was also an excess of lethal cardiac malformations which were not associated with parental consanguinity. The remainder of the excess perinatal mortality was probably due to socio-economic factors. These causes are partly amenable to preventive measures, such as the referral of Pakistani women for expert ultrasonography at 18 to 20 weeks of pregnancy.

Unusual features in the inheritance of ataxia telangiectasia

A prevalence study of ataxia telangiectasia was conducted in the West Midlands, with a population of over 5 million. The prevalence in those aged 50 or less was found to be 1 in 514,000 and the birth frequency to be about 1 in 300,000. A genetic study of 47 families ascertained throughout the United Kingdom was carried out concurrently. A low parental consanguinity rate was found, no parents being first cousins or more closely related, whereas 10% had been expected. The incidence of ataxia telangiectasia in the 79 sibs of index cases was 1 in 7. These two features demonstrate that ataxia telangiectasia may not always be an autosomal recessive condition. Other possible explanations are that some cases are double heterozygotes or new dominant mutations.