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

Evidence that autosomal recessive spastic cerebral palsy-1 (CPSQ1) is caused by a missense variant in HPDL

A subset of individuals diagnosed with cerebral palsy will have an underlying genetic diagnosis. Previously, a missense variant in GAD1 was described as a candidate mutation in a single family diagnosed with autosomal recessive spastic cerebral palsy-1 (CPSQ1; OMIM 603513). Following the ascertainment of a further branch of the CPSQ1 kindred, we found that the previously reported GAD1 variant did not segregate with the neurological disease phenotype in the recently ascertained branch of the kindred. Following genetic linkage studies to map autozygous regions and whole-exome sequencing, a missense variant (c.527 T > C; p. Leu176Pro, rs773333490) in the HPDL gene was detected and found to segregate with disease status in both branches of the kindred. HPDL encodes a 371-amino acid protein (4-Hydroxyphenylpyruvate Dioxygenase Like) that localizes to mitochondria but whose function is uncertain. Recently, biallelic loss of function variants and missense substitution-causing variants in HPDL were reported to cause a childhood onset progressive spastic movement disorder with a variable presentation. These findings suggest that HPDL-related neurological disease may mimic spastic cerebral palsy and that GAD1 should not be included in diagnostic gene panels for inherited cerebral palsy.

Ethnic-specific mortality of infants undergoing congenital heart surgery in England and Wales

PURPOSE

To investigate ethnic differences in mortality for infants with congenital heart defects (CHDs) undergoing cardiac surgery or interventional catheterisation.

DESIGN

Observational study of survival to age 1 year using linked records from routine national paediatric cardiac surgery and intensive care audits. Mortality risk was investigated using multivariable Poisson models with multiple imputation. Predictors included sex, ethnicity, preterm birth, deprivation, comorbidities, prenatal diagnosis, age and weight at surgery, preprocedure deterioration and cardiac diagnosis.

SETTING

All paediatric cardiac surgery centres in England and Wales.

PATIENTS

5350 infants with CHDs born from 2006 to 2009.

MAIN OUTCOME MEASURE

Survival at age 1 year.

RESULTS

Mortality was 83.9 (95% CI 76.3 to 92.1) per 1000 infants, with variation by ethnic group. Compared with those of white ethnicity, infants in British Asian (Indian, Pakistani and Bangladeshi) and 'all other' (Chinese, mixed and other) categories experienced significantly higher mortality by age 1 year (relative risk [RR] 1.52[95% CI 1.19 to 1.95]; 1.62[95% CI 1.20 to 2.20], respectively), specifically during index hospital admission (RR 1.55 [95% CI 1.07 to 2.26]; 1.64 [95% CI 1.05 to 2.57], respectively). Further predictors of mortality included non-cardiac comorbidities, prenatal diagnosis, older age at surgery, preprocedure deterioration and cardiac diagnosis. British Asian infants had higher mortality risk during elective hospital readmission (RR 1.86 [95% CI 1.02 to 3.39]).

CONCLUSIONS

Infants of British Asian and 'all other' non-white ethnicity experienced higher postoperative mortality risk, which was only partly explained by socioeconomic deprivation and access to care. Further investigation of case-mix and timing of risk may provide important insights into potential mechanisms underlying ethnic disparities.

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.

Missense variants in AIMP1 gene are implicated in autosomal recessive intellectual disability without neurodegeneration

AIMP1/p43 is a multifunctional non-catalytic component of the multisynthetase complex. The complex consists of nine catalytic and three non-catalytic proteins, which catalyze the ligation of amino acids to their cognate tRNA isoacceptors for use in protein translation. To date, two allelic variants in the AIMP1 gene have been reported as the underlying cause of autosomal recessive primary neurodegenerative disorder. Here, we present two consanguineous families from Pakistan and Iran, presenting with moderate to severe intellectual disability, global developmental delay, and speech impairment without neurodegeneration. By the combination of homozygosity mapping and next generation sequencing, we identified two homozygous missense variants, p.(Gly299Arg) and p.(Val176Gly), in the gene AIMP1 that co-segregated with the phenotype in the respective families. Molecular modeling of the variants revealed deleterious effects on the protein structure that are predicted to result in reduced AIMP1 function. Our findings indicate that the clinical spectrum for AIMP1 defects is broader than witnessed so far.

Ethnic variation in stillbirth risk and the role of maternal obesity: analysis of routine data from a London maternity unit

BACKGROUND

Approximately 5 in 1,000 deliveries in England and Wales result in stillbirth, with little improvement in figures over the last few decades. The aim of this study was to investigate the association between clinical and socio-demographic factors and stillbirth, with a particular focus on ethnicity and obesity.

METHODS

Analysis of routine maternity data on 53,293 singleton births occurring in a large London teaching hospital between 2004 and 2012. Logistic regression was used to investigate risk factors for stillbirth and to explore potential effect modification.

RESULTS

53,293 deliveries occurred during the time period, of which 329 resulted in a stillbirth (6.2 per 1,000 births). Compared to White women, non-White ethnicity was associated with a doubling of the odds of stillbirth (aOR for Black women 2.15, 95% CI 1.56-2.97; aOR for South Asian women 2.33, 95% CI 1.42-3.83). Obese women had a trend towards higher odds of stillbirth compared to women of recommended BMI (aOR 1.38, 95% CI 0.98-1.96), though this was not significant (p 0.07). Both higher parity (≥2 compared to para 1) and hypertension were associated with a higher odds of stillbirth (parity ≥2 aOR 1.65, 95% CI 1.13-2.39; hypertension aOR 1.84, 95% CI 1.22-2.78) but there was no evidence that area deprivation or maternal age were independently associated with stillbirth in this population. There was some evidence of effect modification between ethnicity and obesity (p value for interaction 0.06), with obesity a particularly strong risk factor for stillbirth in South Asian women (aOR 4.64, 95% CI 1.84-11.70).

CONCLUSIONS

There was a high prevalence of stillbirth in this multi-ethnic urban population. The increased risk of stillbirth observed in non-White women remains after adjusting for other factors. Our finding of possible effect modification between ethnicity and obesity suggests that further research should be conducted in order to improve understanding of the interplay between ethnicity, obesity and stillbirth.

Stillbirth and infant death among generations of Pakistani immigrant descent: a population-based study

OBJECTIVE

To examine the risk of stillbirth and infant death among offspring of Pakistani-born and Norwegian-born women of Pakistani immigrant descent.

DESIGN

Population-based study linking the Medical Birth Registry of Norway to immigration data from Statistics Norway.

SETTING

Norway.

POPULATION

Births to women of Pakistani immigrant descent classified as Pakistani-born (n = 8814) or Norwegian-born (n = 1801), and to the host population of Norwegian descent (n = 712 430) from 1995 to 2010.

METHODS

The relative risk of stillbirth and infant death by country of descent and birth was estimated by odds ratios with 95% confidence intervals (95% CI) using logistic regression.

MAIN OUTCOME MEASURES

Stillbirth and infant death.

RESULTS

Risk of stillbirth was highest in the Pakistani-born group (7.4/1000, 95% CI 5.7-9.4) followed by the Norwegian-born group (5.0/1000, 95% CI 1.7-8.3) and finally the host population (3.5/1000, 95% CI 3.3-3.6). Relative to the host population, risk of stillbirth was higher in both Pakistani-born (odds ratios 2.8, 95% CI 2.2-3.6) and Norwegian-born (odds ratios 2.2, 95% CI 1.1-4.2) groups, after adjustment for year of birth, age, parity and residence. For infant death, absolute risks were 6.9/1000 (95% CI 5.2-8.8), 5.6/1000 (95% CI 2.7-10.2), and 2.9/1000 (95% CI 2.7-3.0), with adjusted odds ratios of 2.8 (95% CI 2.1-3.7) and 2.4 (95% CI 1.3-4.6), respectively.

CONCLUSIONS

An elevated risk of stillbirth and infant death persists across generations of Pakistani immigrant descent living in Norway. While translating into few excess deaths, the elevated risks should be taken into account by obstetric and pediatric care providers.

Developing and evaluating a culturally appropriate genetic service for consanguineous South Asian families

Blackburn with Darwen Primary Care Trust (PCT) provides services to a substantial Asian population in which the practice of consanguineous marriage is common and there is a high incidence of autosomal recessive disorders. The aim was to provide and evaluate a genetic service accessible to consanguineous families from the South Asian community who had a child affected by an autosomal recessive disorder. Information on genetic risk was provided along with the offer of genetic testing for members of the extended family to identify gene carriers and facilitate informed reproductive choices. An Urdu-speaking health visitor was employed to establish a community-based, hospital-linked genetic service in conjunction with local paediatric and regional genetic services offered to parents who had an affected child and 71 of their relatives. The service was evaluated using a specifically designed questionnaire. There was a high uptake of the service (95% of index parents and 92% of relatives to whom it was offered) and a high uptake of carrier testing (94% of relatives to whom it was offered). Eight requests for prenatal diagnosis were made during the course of the service development. Many individuals stated they would consider genetic risk when making future marriage and reproductive plans. Input from a health care worker from the same ethnic background who provided information in their own language was highly valued. Family orientated genetic services for ethnic groups practicing consanguinity can be acceptable and effective when provided in a culturally appropriate manner.

High perinatal mortality rate among immigrants in Brussels

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

What factors predict differences in infant and perinatal mortality in primary care trusts in England? A prognostic model

OBJECTIVE

To identify predictors of perinatal and infant mortality variations between primary care trusts (PCTs) and identify outlier trusts where outcomes were worse than expected.

DESIGN

Prognostic multivariable mixed models attempting to explain observed variability between PCTs in perinatal and infant mortality. We used these predictive models to identify PCTs with higher than expected rates of either outcome.

SETTING

All primary care trusts in England. Population For each PCT, data on the number of infant and perinatal deaths, ethnicity, deprivation, maternal age, PCT spending on maternal services, and "Spearhead" status.

MAIN OUTCOME MEASURES

Rates of perinatal and infant mortality across PCTs.

RESULTS

The final models for infant mortality and perinatal mortality included measures of deprivation, ethnicity, and maternal age. The final model for infant mortality explained 70% of the observed heterogeneity in outcome between PCTs. The final model for perinatal mortality explained 80.5% of the between-PCT heterogeneity. PCT spending on maternal services did not explain differences in observed events. Two PCTs had higher than expected rates of perinatal mortality.

CONCLUSIONS

Social deprivation, ethnicity, and maternal age are important predictors of infant and perinatal mortality. Spearhead PCTs are performing in line with expectations given their levels of deprivation, ethnicity, and maternal age. Higher spending on maternity services using the current configuration of services may not reduce rates of infant and perinatal mortality.

Race, prematurity and immaturity

Compared to white Europeans, Blacks and South Asians have a significantly shorter mean gestational length and a higher incidence of preterm birth. For any given gestational age before 37 weeks, Black and South Asian babies have less risk of respiratory distress syndrome, and the survival rate in Black babies is higher than white Europeans. From 37 weeks of gestation onwards, the perinatal mortality rate in Blacks is higher than in white Europeans, and this appears to be associated with a higher rate of meconium passage and respiratory morbidity. In full term South Asian babies, the late gestation rise in antepartum stillbirth occurs one week earlier than in white Europeans. These patterns remained significant even after adjusting for socioeconomic factors. This suggests that fetal maturity occurs earlier in gestation in Blacks and South Asians when compared to white European babies.

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.

Genetic contribution to high neonatally lethal malformation rate in the United Arab Emirates

OBJECTIVES

We examined the contribution of genetic disorders to congenital anomalies (CA) causing neonatal deaths in the Al Ain Medical District (AMD) in the United Arab Emirates (UAE) because of the high consanguineous marriage rate in the community.

METHODS

Charts of all neonatal deaths in the three perinatal units, which accounted for 99% of all births in AMD (1992-2000), were studied. Data regarding pregnancy, a family history including the level of parental consanguinity, the results of genetic evaluations and neonatal outcomes were recorded as part of an ongoing malformation surveillance system. Causes of death were based on clinical, laboratory and imaging findings.

RESULTS

Of the 508 neonates who died, 212 (42%) had CA, which were the leading cause of death. Forty-four percent of the CA were due to definite genetic disorders and 75% of these were single gene defects. Multisystem malformations were the commonest congenital malformations. Parental consanguinity was associated with a 2-fold increased risk of non-chromosomal multisystem malformations.

CONCLUSIONS

Lethal malformations were the leading cause of neonatal deaths, and parental consanguinity was associated with an increased risk of autosomal recessive disorders. The results underscore the importance of genetic screening and counseling in strategies for further significant reductions in the neonatal mortality rate in the UAE.

An analysis of consanguinity and social structure within the UK Asian population using microsatellite data

We analysed microsatellite genotypes sampled from the Pakistani and Indian communities in Nottingham, UK, to investigate the genetic consequences of substructuring mediated by traditional marriage customs. The application of a recently developed likelihood approach identified significant levels of population substructure within the Pakistani community as a whole, as well as within the finer divisions of castes and biradheri. In addition, high levels of cryptic or unacknowledged consanguinity were detected within subgroups of this community, including biradheri. The Indian sample showed no significant evidence of either substructure or consanguinity. We demonstrate that estimates of disease gene frequencies can be inaccurate unless they are made jointly with estimates of population substructure and consanguinity ((theta congruent to FST) and C). The magnitude of these estimates also highlights the importance of accounting for the finer scale of social structuring when making decisions regarding the risk of recessive disorders in offspring.

A method for distinguishing consanguinity and population substructure using multilocus genotype data

We use the patterns of homozygosity at multiple loci to distinguish between excess homozygosity caused by consanguineous mating and that due to undetected population subdivision (the Wahlund effect). Clarification of the underlying causes of excess homozygosity is of practical importance in explaining the occurrence of recessive genetic disorders and in forensic match probability calculations. We calculated a likelihood surface for two parameters: C, the proportion of the population practicing consanguinity, and theta, the genetic correlation due population subdivision. To illustrate the method, we applied it to multilocus genotypic data of two U.K. Asian populations, one practicing a high frequency of cousin marriage, and another in which caste endogamy was suspected. The method was able to successfully distinguish the different patterns of relatedness. The method also returned accurate estimates of C and theta using simulated data sets. We show how our method can be extended to allow for degrees of inbreeding closer than cousin unions, including selfing. With closer inbreeding, the relatedness of recent ancestors beyond the parents becomes an issue.

Influences of ethnicity on perinatal and child mortality in the Netherlands

AIMS

To investigate the differences in perinatal death and child mortality between different ethnic groups in the Netherlands.

METHODS

Retrospective analysis of data collected between 1990 and 1993 in the national obstetric registry comprising 569 743 births. Retrospective analysis of all death certificates of 0 to 15 year old children routinely collected between 1979 and 1993, comprising 20 211 deaths.

RESULTS

Black mothers had the highest perinatal death rate compared with indigenous Dutch mothers (odds ratio 2.2). Hindustanis (West Indian Asians) had an odds ratio of 1.4 and Mediterraneans 1.3. The increased rate for black and Hindustani women could be fully explained by preterm birth. In the Mediterranean group the differences were explained by teenage pregnancy, grand multiparity, and socioeconomic status rather than prematurity. The death rate of Turkish and Moroccan children was twice as high as that of native Dutch children. For the different diagnostic categories this was: infectious diseases, relative risk (RR) 2.2; hereditary (metabolic) disorders, RR 2.0; accidents and drowning, RR 1.9. One quarter of the Turkish and Moroccan children died while on holiday in their country of origin. Sudden infant death syndrome was twice as high for Turkish infants as for Dutch children and four times higher than for Moroccan infants.

CONCLUSION

Ethnic minorities in the Netherlands have a higher perinatal and child mortality rate than the indigenous Dutch. Apart from socioeconomic differences, sociocultural and lifestyle factors play an important role.

Consanguinity and recurrence risk of stillbirth and infant death

OBJECTIVES

The aim of this study was to estimate the recurrence risk for stillbirth and infant death and compare results for offspring of first-cousin parents with results for offspring of unrelated parents.

METHODS

The study population consisted of all single births with a previous sibling born in Norway between 1967 and 1994. Altogether, 629,888 births were to unrelated parents, and 3466 births were to parents who were first cousins. The risk of stillbirth and infant death was estimated for subsequent siblings contingent on parental consanguinity and survival of the previous sibling.

RESULTS

For unrelated parents, the risk of early death (stillbirth plus infant death) for the subsequent sibling was 17 of 1000 if the previous child survived and 67 of 1000 if the previous child died before 1 year of age. For parents who were first cousins, the risk of early death for the subsequent sibling was 29 of 1000 if the previous child survived and 116 of 1000 if the previous child died.

CONCLUSIONS

The risk of recurrence of stillbirth and infant death is higher for offspring of first-cousin parents compared with offspring of unrelated parents.

Obstetric profiles and perinatal mortality among Pacific Island immigrants in New South Wales, 1990-93

OBJECTIVES

To describe the obstetric profile and perinatal mortality of Pacific Island-born women giving birth in New South Wales (NSW) and assess risk factors associated with the high perinatal death rate previously noted in this immigrant group.

METHOD

Retrospective cohort study based on the Midwives Data Collection in NSW from 1990 to 1993. Births to 5,034 Pacific Island-born women were compared with births to 256,843 Australian-born women.

RESULTS

Pacific Island-born women had fewer teenage pregnancies and were of an older age and higher parity. They were more likely to be married or in a de facto relationship and to present for antenatal care later in the pregnancy. The proportion of low birthweight and preterm birth was similar in the two groups but Pacific Islanders had a higher perinatal mortality rate (14.6/1,000 vs. 10.3/1,000, RR = 1.42, 95% CI = 1.13-1.54). Even at normal and high birthweights, infants of Pacific Island-born women were at greater risk of perinatal death. After adjusting for maternal factors (marital status, insurance status, parity and maternal age) Pacific Islanders were 30% more likely to have a perinatal death (OR = 1.30, 95% CI 1.07-1.54).

CONCLUSIONS

Further analyses of the causes of perinatal death in Pacific Island-born women are needed so appropriate interventions can be implemented.

IMPLICATIONS

The need for the design and evaluation of culturally specific services aimed at improving antenatal care attendance in Pacific Islanders is emphasised. Conventional risk assessment may not adequately predict adverse perinatal outcomes in all populations.

Pattern of central nervous system anomalies in a population with a high rate of consanguineous marriages

Nine thousand six hundred and ten births were prospectively studied in the three major hospitals in Al-Ain, United Arab Emirates (UAE) between October 1995 and January 1997. Babies suspected of, or diagnosed, as having central nervous system (CNS) abnormalities were evaluated by a neonatologist, a clinical geneticist and a pediatric neurologist. Brain computerized tomography/magnetic resonance imaging (CT/MRI) was performed on all babies suspected of having CNS abnormalities. In addition, metabolic screening and chromosome analysis were also performed when indicated. Of the 225 babies with congenital anomalies identified, 31 had CNS abnormalities (3.2/1000). Syndromic abnormalities of the CNS were present in 13 cases (42%), chromosomal abnormalities in one case (3.2%) and the rest included: neural tube defect (NTD) in 11 cases (36%), holoprosencephaly in two cases (6.4%) and hydrocephalus in four cases (12.9%). Detailed analysis of the syndromic types revealed that out of the 13 cases, 12 were inherited as autosomal recessive (AR) and in one case the inheritance was undetermined. Consanguinity with high level of inbreeding was present in 12 cases and the majority of the syndromes identified were extremely rare. The study indicates that CNS anomalies are fairly common in the UAE, particularly, the recessive syndromic types. Careful and detailed analysis of such anomalies is required so that accurate genetic advice can be given.

Migration and health in the European Union

The paper gives a brief overview of a wide spectrum of health issues and problems, ranging from communicable disease to mental health and family formation, which affect migrants and host countries.

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.

Is the risk of cancer increased in Asians living in the UK?

The pattern of cancer in white and Asian (Indian, Pakistani, and Bangladeshi) children living in the West Midlands Health Authority Region was investigated using age standardised incidence rates. Two sets of rates were calculated, a 10 year rate (1982-91) using survey based estimates of the ethnic population and a four year rate (1989-92) using the ethnic population counts from the 1991 census. The 10 year rates showed a significantly higher annual incidence of cancer in Asian (159.1/million/year) than in white (130.8) children. The pattern of cancers in Asian children was different, with an excess of lymphomas and germ cell tumours, and a deficit of rhabdomyosarcomas. These findings were confirmed by the four year rates. Although underestimation of the Asian population probably contributes to the apparent excess, there remains cause for concern that UK Asian children may be at higher risk of cancer. Accurate ethnic population figures and confirmatory studies are urgently required.

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.