Prevalence and descriptive epidemiology of infantile hypertrophic pyloric stenosis in the United States: A multistate, population-based retrospective study, 1999-2010.

BACKGROUND: Antecedents for infantile hypertrophic pyloric stenosis (IHPS) vary across studies; therefore, we conducted a multistate, population-based retrospective study of the prevalence and descriptive epidemiology of IHPS in the United States (US). METHODS: Data for IHPS cases (n = 29,554) delivered from 1999-2010 and enumerated from 11 US population-based birth defect surveillance programs, along with data for live births (n = 14,707,418) delivered within the same birth period and jurisdictions, were analyzed using Poisson regression to estimate IHPS prevalence per 10,000 live births. Additional data on deliveries from 1999-2005 from seven of these programs were analyzed using multivariable logistic regression to estimate adjusted prevalence ratios (aPR)s and 95% confidence intervals (CI)s for selected infant and parental characteristics. RESULTS: Overall, IHPS prevalence from 1999-2010 was 20.09 (95% CI = 19.87, 20.32) per 10,000 live births, with statistically significant increases from 2003-2006 and decreases from 2007-2010. Compared to their respective referents, aPRs were higher in magnitude for males, preterm births, and multiple births, but lower for birth weights <2,500 g. The aPRs for all cases increased with decreasing parental age, maternal education, and maternal parity, but decreased for parental race/ethnicity other than non-Hispanic White. Estimates restricted to isolated cases or stratified by infant sex were similar to those for all cases. CONCLUSIONS: This study covers one of the largest samples and longest temporal period examined for IHPS in the US. Similar to findings reported in Europe, estimates suggest that IHPS prevalence has decreased recently in the US. Additional analyses supported associations with several infant and parental characteristics.

Copy-number variants and candidate gene mutations in isolated split hand/foot malformation.

Split hand/foot malformation (SHFM) is a congenital limb deficiency with missing or shortened central digits. Some SHFM genes have been identified but the cause of many SHFM cases is unknown. We used single-nucleotide polymorphism (SNP) microarray analysis to detect copy-number variants (CNVs) in 25 SHFM cases without other birth defects from New York State (NYS), prioritized CNVs absent from population CNV databases, and validated these CNVs using quantitative real-time polymerase chain reaction (qPCR). We tested for the validated CNVs in seven cases from Iowa using qPCR, and also sequenced 36 SHFM candidate genes in all the subjects. Seven NYS cases had a potentially deleterious variant: two had a p.R225H or p.R225L mutation in TP63, one had a 17q25 microdeletion, one had a 10q24 microduplication and three had a 17p13.3 microduplication. In addition, one Iowa case had a de novo 10q24 microduplication. The 17q25 microdeletion has not been reported previously in SHFM and included two SHFM candidate genes (SUMO2 and GRB2), while the 10q24 and 17p13.3 CNVs had breakpoints within genomic regions that contained putative regulatory elements and a limb development gene. In SHFM pathogenesis, the microdeletion may cause haploinsufficiency of SHFM genes and/or deletion of their regulatory regions, and the microduplications could disrupt regulatory elements that control transcription of limb development genes.

Maternal Antihypertensive Medication Use and Congenital Heart Defects: Updated Results From the National Birth Defects Prevention Study.

Previous NBDPS (National Birth Defects Prevention Study) findings from 1997 to 2003 suggested that maternal antihypertensive use was associated with congenital heart defects (CHDs). We re-examined associations between specific antihypertensive medication classes and specific CHDs with additional NBDPS data from 2004 to 2011. After excluding mothers missing hypertension information or who reported pregestational diabetes mellitus, a multiple birth, or antihypertensive use but no hypertension, we compared self-reported maternal exposure data on 10 625 CHD cases and 11 137 nonmalformed controls. We calculated adjusted odds ratios [95% confidence intervals] to estimate the risk of specific CHDs associated with antihypertensive use during the month before conception through the third month of pregnancy, controlling for maternal age, race/ethnicity, body mass index, first trimester cigarette smoking, and NBDPS site. Overall, 164 (1.5%) case mothers and 102 (0.9%) control mothers reported early pregnancy antihypertensive use for their hypertension. We observed increased risk of 4 CHD phenotypes, regardless of antihypertensive medication class reported: coarctation of the aorta (2.50 [1.52-4.11]), pulmonary valve stenosis (2.19 [1.44-3.34]), perimembranous ventricular septal defect (1.90 [1.09-3.31]), and secundum atrial septal defect (1.94 [1.36-2.79]). The associations for these phenotypes were statistically significant for mothers who reported ß-blocker use or renin-angiotensin system blocker use; estimates for other antihypertensive medication classes were generally based on fewer exposed cases and were less stable but remained elevated. Our results support and expand on earlier NBDPS findings that antihypertensive medication use may be associated with increased risk of specific CHDs, although we cannot completely rule out confounding by underlying disease characteristics.

Rare copy number variants in a population-based investigation of hypoplastic right heart syndrome.

BACKGROUND: Hypoplastic right heart syndrome (HRHS) is a rare congenital defect characterized by underdevelopment of the right heart structures commonly accompanied by an atrial septal defect. Familial HRHS reports suggest genetic factor involvement. We examined the role of copy number variants (CNVs) in HRHS. METHODS: We genotyped 32 HRHS cases identified from all New York State live births (1998-2005) using Illumina HumanOmni2.5 microarrays. CNVs were called with PennCNV and prioritized if they were ≥20 Kb, contained ≥10 SNPs and had minimal overlap with CNVs from in-house controls, the Database of Genomic Variants, HapMap3, and Childrens Hospital of Philadelphia database. RESULTS: We identified 28 CNVs in 17 cases; several encompassed genes important for right heart development. One case had a 2p16-2p23 duplication spanning LBH, a limb and heart development transcription factor. Lbh mis-expression results in right ventricular hypoplasia and pulmonary valve defects. This duplication also encompassed SOS1, a factor associated with pulmonary valve stenosis in Noonan syndrome. Sos1-/- mice display thin and poorly trabeculated ventricles. In another case, we identified a 1.5 Mb deletion associated with Williams-Beuren syndrome, a disorder that includes valvular malformations. A third case had a 24 Kb deletion upstream of the TGFß ligand ITGB8. Embryos genetically null for Itgb8, and its intracellular interactant Band 4.1B, display lethal cardiac phenotypes. CONCLUSION: To our knowledge, this is the first study of CNVs in HRHS. We identified several rare CNVs that overlap genes related to right ventricular wall and valve development, suggesting that genetics plays a role in HRHS and providing clues for further investigation. Birth Defects Research 109:16-26, 2017. © 2016 Wiley Periodicals, Inc.

Copy number variants in a population-based investigation of Klippel-Trenaunay syndrome.

Klippel-Trenaunay syndrome (KTS) is a rare congenital vascular disorder that is thought to occur sporadically; however, reports of familial occurrence suggest a genetic component. We examined KTS cases to identify novel, potentially causal copy number variants (CNVs). We identified 17 KTS cases from all live-births occurring in New York (1998-2010). Extracted DNA was genotyped using Illumina microarrays and CNVs were called using PennCNV software. CNVs selected for follow-up had ≥10 single nucleotide polymorphisms (SNPs) and minimal overlap with in-house controls or controls from the Database of Genomic Variants. We identified 15 candidate CNVs in seven cases; among them a deletion in two cases within transcripts of HDAC9, a histone deacetylase essential for angiogenic sprouting of endothelial cells. One of them also had a duplication upstream of SALL3, a transcription factor essential for embryonic development that inhibits DNMT3A, a DNA methyltransferase responsible for embryonic de novo DNA methylation. Another case had a duplication spanning ING5, a histone acetylation regulator active during embryogenesis. We identified rare genetic variants related to chromatin modification which may have a key role in regulating vascular development during embryogenesis. Further investigation of their implications in the pathogenesis of KTS is warranted. © 2016 Wiley Periodicals, Inc.

Maternal autoimmune disease and birth defects in the National Birth Defects Prevention Study.

BACKGROUND: Little is known about the association between maternal autoimmune disease or its treatment and the risk of birth defects. We examined these associations using data from the National Birth Defects Prevention Study, a multi-site, population-based, case-control study. METHODS: Analyses included 25,116 case and 9897 unaffected control infants with estimated delivery dates between 1997 and 2009. Information on autoimmune disease, medication use, and other pregnancy exposures was collected by means of telephone interview. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for birth defects with five or more exposed cases; crude ORs and exact 95% CIs were estimated for birth defects with three to four exposed cases. RESULTS: Autoimmune disease was reported by 373 mothers (279 case and 94 control mothers). The majority of birth defects evaluated were not associated with autoimmune disease; however, a statistically significant association between maternal autoimmune disease and encephalocele was observed (OR, 4.64; 95% CI, 1.95-11.04). Eighty-two mothers with autoimmune disease used an immune modifying/suppressing medication during pregnancy; this was associated with encephalocele (OR, 7.26; 95% CI, 1.37-24.61) and atrial septal defects (OR, 3.01; 95% CI, 1.16-7.80). CONCLUSION: Our findings suggest maternal autoimmune disease and treatment are not associated with the majority of birth defects, but may be associated with some defects, particularly encephalocele. Given the low prevalence of individual autoimmune diseases and the rare use of specific medications, we were unable to examine associations of specific autoimmune diseases and medications with birth defects. Other studies are needed to confirm these findings. Birth Defects Research (Part A) 106:950-962, 2016. © 2016 Wiley Periodicals, Inc.

Genetic Variants in Isolated Ebstein Anomaly Implicated in Myocardial Development Pathways.

Ebstein anomaly (EA) is a rare heart defect in which the tricuspid valve is malformed and displaced. The tricuspid valve abnormalities can lead to backflow of blood from the right ventricle to the right atrium, preventing proper circulation of blood to the lungs. Although the etiology of EA is largely unresolved, increased prevalence of EA in those with a family history of congenital heart disease suggests EA has a genetic component. Copy number variants (CNVs) are a major source of genetic variation and have been implicated in a range of congenital heart defect phenotypes. We performed a systematic, genome-wide search for CNVs in 47 isolated EA cases using genotyping microarrays. In addition, we used a custom HaloPlex panel to sequence three known EA genes and 47 candidate EA genes. We identified 35 candidate CNVs in 24 (51%) EA cases. Rare sequence variants in genes associated with cardiomyopathy were identified in 11 (23%) EA cases. Two CNVs near the transcriptional repressor HEY1, a member of the NOTCH signaling pathway, were identified in three unrelated cases. All other candidate CNVs were each identified in a single case. At least 11 of 35 candidate CNVs include genes involved in myocardial development or function, including multiple genes in the BMP signaling pathway. We identified enrichment of gene sets involved in histone modification and cardiomyocyte differentiation, supporting the involvement of the developing myocardium in the etiology of EA. Gene set enrichment analysis also identified ribosomal RNA processing, a potentially novel pathway of altered cardiac development in EA. Our results suggest an altered myocardial program may contribute to abnormal tricuspid valve development in EA. Future studies should investigate abnormal differentiation of cardiomyocytes as a potential etiological factor in EA.

Fluconazole use and birth defects in the National Birth Defects Prevention Study.

BACKGROUND: Low-dose fluconazole is used commonly to treat vulvovaginal candidiasis, a condition occurring frequently during pregnancy. Conflicting information exists on the association between low-dose fluconazole use among pregnant women and the risk of major birth defects. OBJECTIVE: We used data from the National Birth Defects Prevention Study to examine this association. STUDY DESIGN: The National Birth Defects Prevention Study is a multisite, population-based, case-control study that includes pregnancies with estimated delivery dates from 1997 to 2011. Information on fluconazole use in early pregnancy was collected by self-report from 31,645 mothers of birth defect cases and 11,612 mothers of unaffected controls. Adjusted odds ratios and 95% confidence intervals were estimated for birth defects with 5 or more exposed cases; crude odds ratios and exact 95% confidence intervals were estimated for birth defects with 3-4 exposed cases. RESULTS: Of the 43,257 mothers analyzed, 44 case mothers and 6 control mothers reported using fluconazole. Six exposed infants had cleft lip with cleft palate, 4 had an atrial septal defect, and each of the following defects had 3 exposed cases: hypospadias, tetralogy of Fallot, d-transposition of the great arteries, and pulmonary valve stenosis. Fluconazole use was associated with cleft lip with cleft palate (odds ratio = 5.53; confidence interval = 1.68-18.24) and d-transposition of the great arteries (odds ratio = 7.56; confidence interval = 1.22-35.45). CONCLUSIONS: The associations between fluconazole and both cleft lip with cleft palate and d-transposition of the great arteries are consistent with earlier published case reports but not recent epidemiologic studies. Despite the larger sample size of the National Birth Defects Prevention Study, fluconazole use was rare. Further investigation is needed in large studies, with particular emphasis on oral clefts and conotruncal heart defects.

Rare copy number variants implicated in posterior urethral valves.

The cause of posterior urethral valves (PUV) is unknown, but genetic factors are suspected given their familial occurrence. We examined cases of isolated PUV to identify novel copy number variants (CNVs). We identified 56 cases of isolated PUV from all live-births in New York State (1998-2005). Samples were genotyped using Illumina HumanOmni2.5 microarrays. Autosomal and sex-linked CNVs were identified using PennCNV and cnvPartition software. CNVs were prioritized for follow-up if they were absent from in-house controls, contained ≥ 10 consecutive probes, were ≥ 20 Kb in size, had ≤ 20% overlap with variants detected in other birth defect phenotypes screened in our lab, and were rare in population reference controls. We identified 47 rare candidate PUV-associated CNVs in 32 cases; one case had a 3.9 Mb deletion encompassing BMP7. Mutations in BMP7 have been associated with severe anomalies in the mouse urethra. Other interesting CNVs, each detected in a single PUV case included: a deletion of PIK3R3 and TSPAN1, duplication/triplication in FGF12, duplication of FAT1--a gene essential for normal growth and development, a large deletion (>2 Mb) on chromosome 17q that involves TBX2 and TBX4, and large duplications (>1 Mb) on chromosomes 3q and 6q. Our finding of previously unreported novel CNVs in PUV suggests that genetic factors may play a larger role than previously understood. Our data show a potential role of CNVs in up to 57% of cases examined. Investigation of genes in these CNVs may provide further insights into genetic variants that contribute to PUV.

Maternal asthma medication use during pregnancy and risk of congenital heart defects.

BACKGROUND: Asthma affects 4% to 8% of pregnant women and studies suggest maternal asthma, particularly when uncontrolled, may be associated with adverse reproductive outcomes. METHODS: We examined self-reported asthma medication use and the risk of congenital heart defects (CHD) in the National Birth Defects Prevention Study, a multi-center, population-based case-control study of selected major structural defects. We evaluated maternal use of bronchodilators and anti-inflammatories during the periconceptional period (1 month before conception through the first 3 pregnancy months) among 7638 infants with CHDs and 8106 nonmalformed controls with estimated delivery dates from 1997 to 2007. We used logistic regression to estimate odds ratios and 95% confidence intervals for 20 types of CHDs. RESULTS: Among asthma medications reported during the periconceptional period among controls, albuterol accounted for 85.1% of all bronchodilator use, and fluticasone, prednisone, and montelukast accounted for 46.1%, 15.6%, and 14.9% of anti-inflammatory use, respectively. Of the women who reported bronchodilators during the periconceptional period, 71.1% reported use throughout pregnancy and only 29.4% reported concurrent use of an anti-inflammatory. We observed one statistically significant association between maternal bronchodilator use only and anomalous pulmonary venous return (odds ratio 2.3, 95% confidence interval 1.1-4.8) among numerous comparisons. CONCLUSION: We did not observe statistically significant associations between the reported use of asthma medications during pregnancy and most specific types of CHDs. Despite limitations in our inability to evaluate asthma status and severity, our study suggests that maternal asthma medication use does not substantially, if at all, increase the risk of CHDs.

Prevalence, Correlates, and Outcomes of Omphalocele in the United States, 1995-2005.

OBJECTIVE: To examine the trends in the prevalence, epidemiologic correlates, and 1-year survival of omphalocele using 1995-2005 data from the National Birth Defects Prevention Network in the United States. METHODS: We examined 2,308 cases of omphalocele over 11 years from 12 state population-based birth defects registries. We used Poisson regression to estimate prevalence and risk factors for omphalocele and Kaplan-Meier survival curves and Cox proportional hazards regression to estimate survival patterns and hazard ratios, respectively, to examine isolated compared with nonisolated cases. RESULTS: Birth prevalence of omphalocele was 1.92 per 10,000 live births with no consistent trend over time. Neonates with omphalocele were more likely to be male (prevalence ratio 1.22, 95% confidence interval [CI] 1.12-1.34), born to mothers 35 years of age or older (prevalence ratio 1.77, 95% CI 1.54-2.04) and younger than 20 years (prevalence ratio 1.34, 95% CI 1.14-1.56), and of multiple births (prevalence ratio 2.22, 95% CI 1.85-2.66). The highest proportion of neonates with omphalocele had congenital heart defects (32%). The infant mortality rate was 28.7%, with 75% of those occurring in the first 28 days. The best survival was for isolated cases and the worst for neonates with chromosomal defects (hazard ratio 7.75, 95% CI 5.40-11.10) and low-birth-weight neonates (hazard ratio 7.51, 95% CI 5.86-9.63). CONCLUSION: Prevalence of omphalocele has remained constant from 1995 to 2005. Maternal age (younger than 20 years and 35 years or older), multiple gestation, and male sex are important correlates of omphalocele, whereas co-occurrence with chromosomal defects and very low birth weight are consistent determinants of 1-year survival among these neonates. LEVEL OF EVIDENCE: II.

Maternal periconceptional alcohol consumption and congenital heart defects.

BACKGROUND: Congenital heart defects (CHDs) are the leading cause of infant death from birth defects. Animal studies suggest in utero alcohol exposure is a teratogen for cardiogenesis; however, results from epidemiologic studies are mixed. METHODS: Data from the National Birth Defects Prevention Study were used to estimate associations between CHDs and case (n = 7076) and control (n = 7972) mother reports of periconceptional (1 month before pregnancy through the first trimester) alcohol consumption with expected delivery dates during 1997 to 2007. CHDs were examined by category (conotruncal, septal, left ventricular outflow tract obstruction, and right ventricular outflow tract obstruction, heterotaxy with CHD) and subtype (e.g., tetralogy of Fallot [TOF]). Alcohol measures examined were any consumption, maximum average drinks per month, binge drinking, and alcohol type. Adjusted odds ratios and 95% confidence intervals were estimated using unconditional logistic regression analysis. RESULTS: Increased risks, albeit marginally statistically significant, were observed for TOF and each maternal alcohol measure examined and for right ventricular outflow tract obstruction and heterotaxy with CHD and consumption of distilled spirits. Significantly reduced risks were observed for several CHD categories (septal defects, left ventricular outflow tract obstruction, and right ventricular outflow tract obstruction) and some corresponding subtypes with different alcohol measures. Significant risks were not observed for the other CHDs examined. CONCLUSION: Analysis of this large, well-defined study sample did not show statistically significant increased risks between measures of maternal alcohol consumption and most CHDs examined. These findings may reflect, in part, limitations with retrospective exposure assessment or unmeasured confounders. Additional studies with continued improvement in measurement of alcohol consumption are recommended.

Sex ratios among infants with birth defects, National Birth Defects Prevention Study, 1997-2009.

A small number of population-based studies have examined sex differences among infants with birth defects. This study presents estimates of sex ratio for both isolated cases and those with multiple congenital anomalies, as well as by race/ethnicity. Male-female sex ratios and their 95% confidence intervals were calculated for 25,952 clinically reviewed case infants included in the National Birth Defects Prevention Study (1997-2009), a large population-based case-control study of birth defects. The highest elevations in sex ratios (i.e., male preponderance) among isolated non-cardiac defects were for craniosynostosis (2.12), cleft lip with cleft palate (2.01), and cleft lip without cleft palate (1.78); the lowest sex ratios (female preponderance) were for choanal atresia (0.45), cloacal exstrophy (0.46), and holoprosencephaly (0.64). Among isolated cardiac defects, the highest sex ratios were for aortic stenosis (2.88), coarctation of the aorta (2.51), and d-transposition of the great arteries (2.34); the lowest were multiple ventricular septal defects (0.52), truncus arteriosus (0.63), and heterotaxia with congenital heart defect (0.64). Differences were observed by race/ethnicity for some but not for most types of birth defects. The sex differences we observed for specific defects, between those with isolated versus multiple defects, as well as by race/ethnicity, demonstrate patterns that may suggest etiology and improve classification.

Prevalence of Duchenne and Becker muscular dystrophies in the United States.

OBJECTIVE: To estimate prevalence of childhood-onset Duchenne and Becker muscular dystrophies (DBMD) in 6 sites in the United States by race/ethnicity and phenotype (Duchenne muscular dystrophy [DMD] or Becker muscular dystrophy [BMD]). METHODS: In 2002, the Centers for Disease Control and Prevention established the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet) to conduct longitudinal, population-based surveillance and research of DBMD in the United States. Six sites conducted active, multiple-source case finding and record abstraction to identify MD STARnet cases born January 1982 to December 2011. We used cross-sectional analyses to estimate prevalence of DBMD per 10 000 boys, ages 5 to 9 years, for 4 quinquennia (1991-1995, 1996-2000, 2001-2005, and 2006-2010) and prevalence per 10 000 male individuals, ages 5 to 24 years, in 2010. Prevalence was also estimated by race/ethnicity and phenotype. RESULTS: Overall, 649 cases resided in an MD STARnet site during ≥1 quinquennia. Prevalence estimates per 10 000 boys, ages 5 to 9 years, were 1.93, 2.05, 2.04, and 1.51, respectively, for 1991-1995, 1996-2000, 2001-2005, and 2006-2010. Prevalence tended to be higher for Hispanic individuals than non-Hispanic white or black individuals, and higher for DMD than BMD. In 2010, prevalence of DBMD was 1.38 per 10 000 male individuals, ages 5 to 24 years. CONCLUSIONS: We present population-based prevalence estimates for DBMD in 6 US sites. Prevalence differed by race/ethnicity, suggesting potential cultural and socioeconomic influences in the diagnosis of DBMD. Prevalence also was higher for DMD than BMD. Continued longitudinal surveillance will permit us to examine racial/ethnic and socioeconomic differences in treatment and outcomes for MD STARnet cases.

Fetal alcohol syndrome among children aged 7-9 years - Arizona, Colorado, and New York, 2010.

Fetal alcohol syndrome (FAS) is a serious birth defect and developmental disorder caused by in utero exposure to alcohol. Assessment of the public health burden of FAS through surveillance has proven difficult; there is wide variation in reported prevalence depending on the study population and surveillance method. Generally, records-based birth prevalence studies report estimates of 0.2-1.5 per 1,000 live births, whereas studies that use in-person, expert assessment of school-aged children in a community report estimates of 6-9 per 1,000 population. The Fetal Alcohol Syndrome Surveillance Network II addressed some of the challenges in records-based ascertainment by assessing a period prevalence of FAS among children aged 7‒9 years in Arizona, Colorado, and New York. The prevalence across sites ranged from 0.3 to 0.8 per 1,000 children. Prevalence of FAS was highest among American Indian/Alaska Native children and lowest among Hispanic children. These estimates continue to be much lower than those obtained from studies using in-person, expert assessment. Factors that might contribute to this discrepancy include 1) inadequate recognition of the physical and behavioral characteristics of FAS by clinical care providers; 2) insufficient documentation of those characteristics in the medical record; and 3) failure to consider prenatal alcohol exposure with diagnoses of behavioral and learning problems. Addressing these factors through training of medical and allied health providers can lead to practice changes, ultimately increasing recognition and documentation of the characteristics of FAS.

Maternal cigarette, alcohol, and coffee consumption in relation to risk of clubfoot.

BACKGROUND: Clubfoot is associated with maternal cigarette smoking in several studies, but it is not clear if this association is confined to women who smoke throughout the at-risk period. Maternal alcohol and coffee drinking have not been well studied in relation to clubfoot. METHODS: The present study used data from a population-based case-control study of clubfoot conducted in Massachusetts, New York, and North Carolina from 2007 to 2011. Mothers of 646 isolated clubfoot cases and 2037 controls were interviewed about pregnancy events and exposures, including the timing and frequency of cigarette smoking, alcohol intake, and coffee drinking. RESULTS: More mothers of cases than controls reported smoking during early pregnancy (28.9% vs. 19.1%). Of women who smoked when they became pregnant, those who quit in the month after a first missed period had a 40% increase in clubfoot risk and those who continued to smoke during the next 3 months had more than a doubling in risk, after controlling for demographic factors, parity, obesity, and specific medication exposures. Adjusted odds ratios for women who drank >3 servings of alcohol or coffee per day throughout early pregnancy were 2.38 and 1.77, respectively, but the numbers of exposed women were small and odds ratios were unstable. CONCLUSIONS: Clubfoot risk appears to be increased for offspring of women who smoke cigarettes, particularly those who continue smoking after pregnancy is recognisable, regardless of amount. For alcohol and coffee drinkers, suggested increased risks were only observed in higher levels of intake.

Novel copy-number variants in a population-based investigation of classic heterotaxy.

PURPOSE: Heterotaxy is a clinically and genetically heterogeneous disorder. We investigated whether screening cases restricted to a classic phenotype would result in the discovery of novel, potentially causal copy-number variants. METHODS: We identified 77 cases of classic heterotaxy from all live births in New York State during 1998-2005. DNA extracted from each infant's newborn dried blood spot was genotyped with a microarray containing 2.5 million single-nucleotide polymorphisms. Copy-number variants were identified with PennCNV and cnvPartition software. Candidates were selected for follow-up if they were absent in unaffected controls, contained 10 or more consecutive probes, and had minimal overlap with variants published in the Database of Genomic Variants. RESULTS: We identified 20 rare copy-number variants including a deletion of BMP2, which has been linked to laterality disorders in mice but not previously reported in humans. We also identified a large, terminal deletion of 10q and a microdeletion at 1q23.1 involving the MNDA gene; both are rare variants suspected to be associated with heterotaxy. CONCLUSION: Our findings implicate rare copy-number variants in classic heterotaxy and highlight several candidate gene regions for further investigation. We also demonstrate the efficacy of copy-number variant genotyping in blood spots using microarrays.

Population-based study to determine mortality in spina bifida: New York State Congenital Malformations Registry, 1983 to 2006.

BACKGROUND: The lifetime risk of death among individuals with spina bifida is 10-times higher compared with the general population. A population-based analysis on cause-specific mortality among individuals spina bifida is lacking. METHODS: Using statewide, population-based New York Congenital Malformations Registry, we examined all births between years 1983 and 2006, and identified 1988 births with spina bifida and 10,951 births with congenital hypertrophic pyloric stenosis (CHPS). We linked registry records to birth and death files from vital records, and determined age- and cause-specific mortality for isolated and multiple spina bifida, and compared the findings with the less fatal CHPS. RESULTS: Mortality in spina bifida is significantly high compared with CHPS (16.9% vs. 0.96%, respectively). The probability of survival in spina bifida was lower compared with CHPS. A majority of the deaths in spina bifida occurred in infants within the first year of birth; however, an increased risk of death persisted in young adulthood for both isolated and multiple cases of spina bifida. The common causes of death in children with spina bifida were hydrocephalus, infections, cardiac anomalies, pneumonia, and pulmonary embolism; while infections, heart or kidney failure, injuries and neoplasms contributed to deaths in adults. CONCLUSION: We conclude that mortality in spina bifida is a large concern, and individuals living with the defect require improved clinical care for lethal medical complications. Primary prevention of spina bifida through mandatory folic acid fortification remains as the best strategy to reduce both disability and mortality associated with this defect across the world.

Analysis of polychlorinated biphenyls and organochlorine pesticides in archived dried blood spots and its application to track temporal trends of environmental chemicals in newborns.

Dried blood spots (DBS) collected from infants shortly after birth for the newborn screening program (NSP) in the United States are valuable resources for the assessment of exposure to environmental chemicals in newborns. The NSP was debuted as a public health program in the United States in the 1960s; and the DBS samples collected over a period of time can be used in tracking temporal trends in exposure to environmental chemicals by newborns. In this study, polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were measured in DBS samples collected from newborns in Upstate New York from 1997 to 2011 by gas chromatography-high resolution mass spectrometry (GC-HRMS). Twelve PCBs and two OCPs were found in DBS samples at a detection rate above 50% (n=51). The mean whole blood concentration of ΣPCBs (sum of 12 congeners) over the 15-year period was 1.06 ng/mL, followed by p,p'-DDE (0.421 ng/mL) and HCB (0.065 ng/mL). The measured concentrations of PCBs and p,p'-DDE in infants'blood were comparable to those reported in cord blood, suggesting maternal/trans-placental transfer of these compounds from mothers to fetuses. The concentrations of ΣPCBs and p,p'-DDE in blood samples of infants decreased significantly between 1997 and 2001, and no significant reduction was found thereafter. This observation is consistent with the trends reported for these chemicals in other human tissues in the United States.

Medication use in pregnancy in relation to the risk of isolated clubfoot in offspring.

Clubfoot, a common major structural malformation, develops early in gestation. Epidemiologic studies have identified higher risks among boys, first-born children, and babies with a family history of clubfoot, but studies of risks associated with maternal exposures are lacking. We conducted the first large-scale, population-based, case-control study of clubfoot with detailed information on maternal medication use in pregnancy. Study subjects were ascertained from birth defect registries in Massachusetts, New York, and North Carolina during 2007-2011. Cases were 646 mothers of children with clubfoot without other major structural malformations (i.e., isolated clubfoot); controls were mothers of 2,037 children born without major malformations. Mothers were interviewed within 12 months of delivery about medication use, including product, timing, and frequency. Odds ratios were estimated for exposure to 27 medications in pregnancy months 2-4 after adjustment for study site, infant sex, first-born status, body mass index (weight (kg)/height (m)(2)), and smoking. Odds ratios were less than 1.20 for 14 of the medications; of the remainder, most odds ratios were only slightly elevated (range, 1.21-1.66), with wide confidence intervals. The use of antiviral drugs was more common in clubfoot cases than in controls (odds ratio = 4.22, 95% confidence interval: 1.52, 11.73). Most of these results are new findings and require confirmation in other studies.