Cerebral Palsy Research Group publications
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Browsing Cerebral Palsy Research Group publications by Author "Dekker, G."
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Item Metadata only Antenatal causes of cerebral palsy: associations between inherited thrombophilias, viral and bacterial infection, and inherited susceptibility to infection(Lippincott Williams & Wilkins, 2003) Gibson, C.; MacLennan, A.; Goldwater, P.; Dekker, G.Cerebral palsy rates of 2 in every 1,000 births have varied little over the last 40 years, despite improvements in obstetric care. In the past, cerebral palsy was thought to be due to poor obstetric care and management; however, epidemiological studies have refuted this, suggesting that there is usually an antenatal timing to the neuropathology of cerebral palsy. There are many known risk factors for cerebral palsy, including multiple gestation, prematurity, and low birth weight. Recently, intrauterine infection, maternal pyrexia, and the presence of thrombophilic disorders (thrombophilia) have been identified as major risk factors for subsequent cerebral palsy. This review examines the links between intrauterine infection, the fetal inflammatory response, and thrombophilia as possible causes of cerebral palsy. The interactions of viral or bacterial infections during pregnancy, normal or abnormal fetal cytokine responses, and hereditary fetal thrombophilias as antenatal causes of the neuropathology of cerebral palsy are now areas of research priority. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians LEARNING OBJECTIVES: After completion of this article, the reader will be able to describe the condition cerebral palsy, list the risk factors for the development of cerebral palsy, outline the ultrasound findings associated with cerebral palsy, and point out other conditions associated with cerebral palsy.Item Metadata only Apolipoprotein E genotype is not associated with cerebral palsy(Wiley, 2009) McMichael, G.; Gibson, C.; MacLennan, A.; Goldwater, P.; Haan, E.; Priest, K.; Dekker, G.; International Cerebral Palsy Conference (3rd : 2009 : Sydney, New South Wales); Robinson InstituteItem Metadata only Association between apolipoprotein E genotype and cerebral palsy is not confirmed in a caucasian population(Springer, 2008) McMichael, G.; Gibson, C.; Goldwater, P.; Haan, E.; Priest, K.; Dekker, G.; MacLennan, A.Apolipoprotein E (APOE) plays a significant role in lipid metabolism and has been implicated in the growth and repair of injured neurons. Two small studies have suggested an association between APOE genotype and cerebral palsy. We investigated if APOE genotype is associated with an increased risk for cerebral palsy, influences the type of cerebral palsy or interacts with prenatal viral infection to influence risk of cerebral palsy. The population-based case-control study comprised newborn screening cards of 443 Caucasian patients with cerebral palsy and 883 Caucasian matched controls. APOE genotyping was performed on DNA extracted from dried blood spots. Allelic and genotypic frequencies did not differ between cases and controls and combined frequencies were 0.10 (ε2), 0.76 (ε3), 0.14 (ε4), 0.03 (ε2/ε2), 0.10 (ε2/ε3), 0.03 (ε2/ε4), 0.02 (ε4/ε4), 0.21 (ε3/ε4), 0.61 (ε3/ε3). APOE genotype was correlated with cerebral palsy, type of cerebral palsy, gestation at birth and the presence of viral nucleic acids detected in previous work. Analysis by gestational age (all gestational ages, ≥37, 32–36 and <32 weeks) and type of cerebral palsy (all types, diplegia, hemiplegia and quadriplegia) showed no association between APOE genotype and cerebral palsy in this Caucasian population. An association between prenatal viral infection, APOE genotype and cerebral palsy was not demonstrated. These results did not confirm an association between APOE genotype, cerebral palsy, type of cerebral palsy and prenatal infection in a Caucasian population. Given the low frequency of APOE ε2 and some of the heterozygote and homozygote combinations in this study, a larger study is assessing this further.Item Metadata only Associations between fetal inherited thrombophilia and adverse pregnancy outcomes(Mosby Inc, 2006) Gibson, C.; MacLennan, A.; Janssen, N.; Kist, W.; Hague, W.; Haan, E.; Goldwater, P.; Priest, K.; Dekker, G.Objective: The purpose of this study was to investigate associations between fetal inherited thrombophilia and adverse pregnancy outcomes, including pregnancy-induced hypertensive disorders (PIHD), antepartum hemorrhage (APH), small-for-gestational age <10th percentile (SGA), and preterm birth (PTB). Study design: Seven hundred and seventeen cases and 609 controls were genotyped for Factor V Leiden (FVL, G1691A), Prothrombin gene mutation (PGM, G20210A), and Methylenetetrahydrofolate reductase (MTHFR) C677T and MTHFR A1298C using DNA from newborn screening cards. Results: For babies born <28 weeks' gestation, PGM was associated with an increased risk of SGA (OR 6.40, 95%CI 1.66-24.71) and APH with SGA (OR 6.35, 95%CI 1.63-24.75). Homozygous MTHFR A1298C was associated with an increased risk of SGA for babies born 28-31 weeks gestation (OR 4.00, 95%CI 1.04-15.37), and with APH and SGA for babies born <32 weeks' gestation (OR 3.57, 95%CI 1.09-11.66). Homozygous MTHFR C677T was associated with a reduced risk of PTB and SGA (OR 0.52, 95%CI 0.28-0.96) for babies born 32 to 36 weeks' gestation. Homozygous FVL decreased the risk of PTB <32 weeks' gestation (OR 0.55, 95%CI 0.31-0.98). Conclusion: Fetal thrombophilic polymorphisms may be related to adverse pregnancy outcomes, in particular SGA.Item Metadata only Associations between inherited thrombophilias, gestational age, and cerebral palsy(Mosby Inc, 2005) Gibson, C.; MacLennan, A.; Hague, W.; Haan, E.; Priest, K.; Chan, A.; Dekker, G.Objective: This study was undertaken to investigate associations between inherited thrombophilic polymorphisms and cerebral palsy (CP) in a large case-control study. Study design: This is a population-based case-control study. Genomic DNA from newborn screening cards of 443 white CP cases and 883 white controls was tested for factor V Leiden (FVL, G1691A), prothrombin gene mutation (PGM, G20210A), and methylenetetrahydrofolate reductase (MTHFR) C677T and MTHFR A1298C. Results: MTHFR C677T was associated with an increased risk of developing any CP (32-36 weeks' gestation, homozygous odds ratio [OR] 2.55, 95% CI 1.12-5.74; heterozygous OR 1.91, 95% CI 1.01-3.66). MTHFR C677T was also associated with diplegia at both less than 32 weeks' gestation (homozygous OR 2.76, 95% CI 1.21-6.12) and all gestations (heterozygous OR 1.58 95%, CI 1.02-2.45). For children less than 32 weeks, FVL homozygosity may be associated with an increase in the risk of developing quadriplegia (OR 9.12, 95% CI 0.86-53.71). MTHFR A1298C (heterozygous) was associated with a reduced risk of diplegia developing at 32 to 36 weeks' gestation (OR 0.16, 95% CI 0.02-0.70). There were no associations between any type of CP and thrombophilia for children born 37 weeks or greater. Heterozygous PGM and homozygous MTHFR C677T combined were associated with quadriplegia at all gestational ages (OR 5.33, 95% CI 1.06-23.25). Conclusion: MTHFR C677T approximately doubles the risk of CP in preterm infants. A combination of homozygous MTHFR C677T and heterozygous PGM increases the risk of quadriplegia 5-fold at all gestational ages.Item Metadata only Candidate Genes and Cerebral Palsy: A Population-Based Study(Amer Acad Pediatrics, 2008) Gibson, C.; MacLennan, A.; Dekker, G.; Goldwater, P.; Sullivan, T.; Munroe, D.; Tsang, S.; Stewart, C.; Nelson, K.Objective
The objective of this study was to examine whether selected genetic polymorphisms in the infant are associated with later-diagnosed cerebral palsy.Methods
A population-based case-control study was conducted of 28 single-nucleotide polymorphisms measured in newborn screening blood spots. A total of 413 children with later-diagnosed cerebral palsy were born to white women in South Australia in 1986-1999, and there were 856 control children. Distributions of genotypic frequencies were examined in total cerebral palsy, in gestational age groups, and by types of cerebral palsy and gender. Genotyping was performed by using a TaqMan assay.Results
For inducible nitric-oxide synthase, possession of the T allele was more common in all children with cerebral palsy and for heterozygotes who were born at term. For lymphotoxin alpha, homozygous variant status was associated with risk for cerebral palsy and with spastic hemiplegic or quadriplegic cerebral palsy. Among term infants, heterozygosity for the endothelial protein C receptor single-nucleotide polymorphism was more frequent in children with cerebral palsy. In preterm infants, the variant A allele of interleukin 8 and heterozygosity for the beta-2 adrenergic receptor were associated with cerebral palsy risk. Interleukin 8 heterozygote status was associated with spastic diplegia. Variants of several genes were associated with cerebral palsy in girls but not in boys.Conclusions
Two of the 28 single-nucleotide polymorphisms examined were associated with all types of spastic cerebral palsy in both gestational age groups and others with cerebral palsy in gestational age or cerebral palsy subgroups. Some of these associations support previous findings. There may be a genetic contribution to cerebral palsy risk, and additional investigation is warranted of genes and gene-environment interactions in cerebral palsy.Item Metadata only Cytomegalovirus and Epstein–Barr virus may be associated with some cases of cerebral palsy(Taylor & Francis Ltd, 2012) McMichael, G.; MacLennan, A.; Gibson, C.; Alvino, E.; Goldwater, P.; Haan, E.; Dekker, G.Objective: Intrauterine infection is a risk factor for cerebral palsy. Previous work reported a high frequency of viral DNA in newborn screening cards from cerebral palsy cases and controls possibly due to contamination. Methods: Retrospective case-control study using improved methodologies to minimize contamination during PCR-based detection of viral DNA sequences. Newborn screening cards of 339 Caucasian children with cerebral palsy and 594 controls were examined. Viruses tested were herpes simplex viruses 1 and 2 (HSV1 and 2), varicella zoster virus (VZV), Epstein–Barr virus (EBV), cytomegalovirus (CMV), human herpes viruses 6, 7 and 8 (HHV6, HHV7 and HHV8), and parvovirus B19. Genotyping was performed on DNA extracted from dried blood spots. Results: CMV and EBV were detected in 5 (1.5%) and 3 (0.9%) of 339 cases, respectively, but not in controls (p = 0.047 and 0.006). Frequencies of detection of the other viruses examined were similar for cases and controls. DNA from at least one of the nine viruses tested was found in 4.4% of cases and 3.1% of controls [OR 1.4 95% CI (0.71–2.76)]. Conclusion: Evidence of congenital viral infection was uncommon in cases of cerebral palsy and controls. However, CMV and EBV were significantly associated with cerebral palsy.Item Metadata only DNA from Buccal Swabs Suitable for High-Throughput SNP Multiplex Analysis(The Association of Biomolecular Resource Facilities, 2009) McMichael, G.; Gibson, C.; O'Callaghan, M.; Goldwater, P.; Dekker, G.; Haan, E.; MacLennan, A.We sought a convenient and reliable method for collection of genetic material that is inexpensive and noninvasive and suitable for self-collection and mailing and a compatible, commercial DNA extraction protocol to meet quantitative and qualitative requirements for high-throughput single nucleotide polymorphism (SNP) multiplex analysis on an automated platform. Buccal swabs were collected from 34 individuals as part of a pilot study to test commercially available buccal swabs and DNA extraction kits. DNA was quantified on a spectrofluorometer with Picogreen dsDNA prior to testing the DNA integrity with predesigned SNP multiplex assays. Based on the pilot study results, the Catch-All swabs and Isohelix buccal DNA isolation kit were selected for our high-throughput application and extended to a further 1140 samples as part of a large cohort study. The average DNA yield in the pilot study (n=34) was 1.94 μg ± 0.54 with a 94% genotyping pass rate. For the high-throughput application (n=1140), the average DNA yield was 2.44 μg ± 1.74 with a ≥93% genotyping pass rate. The Catch-All buccal swabs are a convenient and cost-effective alternative to blood sampling. Combined with the Isohelix buccal DNA isolation kit, they provided DNA of sufficient quantity and quality for high-throughput SNP multiplex analysis.Item Metadata only Epidemiologic associations with cerebral palsy(Lippincott Williams & Wilkins, 2011) O'Callaghan, M.; MacLennan, A.; Gibson, C.; McMichael, G.; Haan, E.; Broadbent, J.; Goldwater, P.; Dekker, G.Objective
To estimate epidemiologic risk factors for cerebral palsy.Methods
Data were collected by linkage to state-based perinatal repositories and cerebral palsy registers and using a maternal questionnaire. The cohort included 587 individuals with cerebral palsy and 1,154 non-cerebral palsy controls.Results
The following factors were associated with cerebral palsy: recorded maternal infection during pregnancy (41.4% patients compared with 31.3% controls; odds ratio [OR] 1.55, 95% confidence interval 1.26-1.91), small for gestational age ([birth weight less than third customized centile] 43.9% patients compared with 6.3% controls; OR 11.75, 6.25-22.08), gestational age less than 32 weeks (29.3% patients compared with 0.7% controls; OR 59.20, 28.87-121.38), multiple birth (OR 6.62, 4.00-10.95), a relative with cerebral palsy (OR 1.61, 1.12-2.32), breech position (13.7% patients compared with 6.0% controls; OR 2.48, 1.76-3.49), bleeding at any time in pregnancy (29.3% patients compared with 16.9% controls; OR 2.04, 1.61-2.58), male sex (58.8% patients compared with 45.8% controls; OR 1.68, 1.38-2.06), multiple miscarriage (7.7% patients compared with 3.5% controls; OR 2.30, 1.38-3.82), smoking (14.0% patients compared with 10.6% controls; OR 1.37, 1.02-1.85), and illicit drug use (3.3% patients compared with 1.5% controls; OR 2.22, 1.14-4.30). Factors not associated with cerebral palsy were "disappearing twin," diabetes, maternal body mass index, hypertension, alcohol consumption, anemia, maternal hypothyroidism, forceps or vacuum delivery, and maternal age.Conclusion
Preterm birth, intrauterine growth restriction, perinatal infection, and multiple birth present the largest risks for a cerebral palsy outcome. Reassuringly, upper respiratory tract and gastrointestinal infections during pregnancy were not associated with cerebral palsy.Level of evidence
II.Item Metadata only Fetal and maternal candidate single nucleotide polymorphism associations with Cerebral Palsy: a case-control study(Amer Acad Pediatrics, 2012) O'Callaghan, M.; MacLennan, A.; Gibson, C.; McMichael, G.; Haan, E.; Broadbent, J.; Goldwater, P.; Painter, J.; Montgomery, G.; Dekker, G.; Australian Collaborative Cerebral Palsy Research GroupObjective
Previous studies have suggested associations between certain genetic variants and susceptibility to cerebral palsy (CP). This study was designed to assess established and novel maternal and child genetic and epidemiologic risk factors for CP along with their interactions.Methods
DNA from 587 case and 1154 control mother-child pairs was analyzed. A panel of 35 candidate single nucleotide polymorphisms (SNPs) were examined and included SNPs in genes associated with (1) thrombophilia, (2) inflammation, and (3) risk factors for CP (eg, preterm birth). Comparisons were specified a priori and made by using a χ(2) test.Results
There were 40 fetal and 28 maternal associations with CP when analyzed by CP subtype, gestational age, genotypes of apolipoprotein E, and haplotypes of mannose-binding-lectin. After Bonferroni correction for multiple testing, no fetal or maternal candidate SNP was associated with CP or its subtypes. Only fetal carriage of prothrombin gene mutation remained marginally associated with hemiplegia in term infants born to mothers with a reported infection during pregnancy. Odds ratio directions of fetal SNP associations were compared with previously reported studies and confirmed no trend toward association.Conclusions
Except for the prothrombin gene mutation, individual maternal and fetal SNPs in our candidate panel were not found to be associated with CP outcome. Past reported SNP associations with CP were not confirmed, possibly reflecting type I error from small numbers and multiple testing in the original reports.Item Metadata only Fetal exposure to herpesviruses may be associated with pregnancy-induced hypertensive disorders and preterm birth in a Caucasian population(Blackwell Publishing Ltd, 2008) Gibson, C.; Goldwater, P.; MacLennan, A.; Haan, E.; Priest, K.; Dekker, G.Objective
To investigate the role of fetal viral infection in the development of a range of adverse pregnancy outcomes (APOs), including pregnancy-induced hypertensive disorders (PIHD), antepartum haemorrhage (APH), birthweight <10th percentile (small for gestational age, SGA) and preterm birth (PTB).Design
Population-based case-control study.Setting
Laboratory-based study.Population
The newborn screening cards of 717 adverse pregnancy cases and 609 controls.Methods
Newborn screening cards were tested for RNA from enteroviruses and DNA from herpesviruses using polymerase chain reaction (PCR). The herpesviruses were detected using two PCRs, one detecting nucleic acids from herpes simplex virus (HSV)-1, HSV-2, Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human herpesvirus (HHV)-8, hereafter designated Herpes PCR group A viruses, and the other detecting nucleic acids from varicella-zoster virus (VZV), HHV-6 and HHV-7, hereafter designated Herpes PCR group B viruses.Main outcome measure
Odds ratios and 95% CIs for specific APOs.Results
For both term and PTBs, the risk of developing PIHD was increased in the presence of DNA from Herpes PCR group B viruses (OR 3.57, 95% CI 1.10-11.70), CMV (OR 3.89, 95% CI 1.67-9.06), any herpesvirus (OR 5.70, 95% CI 1.85-17.57) and any virus (OR 5.17, 95% CI 1.68-15.94). The presence of CMV was associated with PTB (OR 1.61, 95% CI 1.14-2.27). No significant association was observed between SGA or APH and exposure to viral infection.Conclusions
Fetal exposure to herpesvirus infection was associated with PIHD for both term and PTBs in this exploratory study. Exposure to CMV may also be associated with PTB. These findings need confirmation in future studies.Item Metadata only Fetal MBL2 haplotypes combined with viral exposure are associated with adverse pregnancy outcomes(Taylor & Francis Ltd, 2011) Gibson, C.; MacLennan, A.; Haan, E.; Priest, K.; Dekker, G.Objective. To investigate the roles of inherited polymorphisms in the MBL2 gene and exposure to viral infection in the development of a range of adverse pregnancy outcomes, including birthweight <10th percentile (small-for-gestational age, SGA), antepartum hemorrhage (APH), pregnancy-induced hypertensive disorders (PIHD), and preterm birth (PTB). Methods. This was a case–control study using DNA from newborn screening cards of 717 cases (babies with at least one of the adverse pregnancy outcomes listed above) and 609 controls, to screen for six polymorphisms within the MBL2 gene. These combine to create haplotypes with high (HYPA), intermediate (LYQA, LYPA), low (LXPA), and defective (HYPD, LYQC, LYPB) circulating MBL2 levels. Results. Significant associations were found between variant MBL2 haplotypes and SGA (LYPA <32 weeks OR 5.37, 95% CI 1.50–17.27), antepartum hemorrhage (LYPA <37 weeks OR 2.29, 95% CI 1.25–4.18), and PIHD (LYQC <32 weeks (OR 17.89, 95% CI 2.20–139.57). Evidence of exposure to infection increased the effect of these associations, (SGA OR 17.00, 95% CI 1.03–252.48; APH OR 5.67, 95% CI 1.73–18.84; PIHD OR 23.80, 95% CI 1.08–1414.76), while no evidence of exposure to infection demonstrated no associations. PTB was significantly associated with the defective HYPD haplotype with evidence of exposure to infection (OR 6.14, 95% CI 1.21–29.89). Conclusions. This research suggests that the combination of fetal MBL2 haplotypes and exposure to in utero viral infection increases the risk of adverse pregnancy outcomes, including PTB, antepartum hemorrhage, small-for-gestational age and PIHD.Item Open Access Genetic and clinical contributions to cerebral palsy: A multi-variable analysis(Blackwell Publishing Asia, 2013) O'Callaghan, M.; MacLennan, A.; Gibson, C.; McMichael, G.; Haan, E.; Broadbent, J.; Baghurst, P.; Goldwater, P.; Dekker, G.Aim
This study aims to examine single nucleotide polymorphism (SNP) associations with cerebral palsy in a multi-variable analysis adjusting for potential clinical confounders and to assess SNP-SNP and SNP-maternal infection interactions as contributors to cerebral palsy.Methods
A case control study including 587 children with cerebral palsy and 1154 control children without cerebral palsy. Thirty-nine candidate SNPs were genotyped in both mother and child. Data linkage to perinatal notes and cerebral palsy registers was performed with a supplementary maternal pregnancy questionnaire. History of known maternal infection during pregnancy was extracted from perinatal databases.Results
Both maternal and fetal carriage of inducible nitric oxide synthase SNP rs1137933 were significantly negatively associated with cerebral palsy in infants born at less than 32 weeks gestation after adjustment for potential clinical confounders and correction for multiple testing (odds ratio 0.55, 95% confidence interval 0.38-0.79; odds ratio 0.57, 95% confidence interval 0.4-0.82, respectively). Analysis did not show any statistically significant SNP-SNP or SNP-maternal infection interactions after correction for multiple testing.Conclusions
Maternal and child inducible nitric oxide synthase SNPs are associated with reduced risk of cerebral palsy in infants born very preterm. There was no evidence for statistically significant SNP-SNP or SNP-maternal infection interactions as modulators of cerebral palsy risk.Item Metadata only Genetic polymorphisms and spontaneous preterm birth(Lippincott Williams & Wilkins, 2007) Gibson, C.; MacLennan, A.; Dekker, G.; Goldwater, P.; Dambrosia, J.; Munroe, D.; Tsang, S.; Stewart, C.; Nelson, K.Objective
To examine whether selected genetic polymorphisms in the infant are associated with spontaneous preterm birth (less than 37 weeks) among children with or without later-diagnosed cerebral palsy.Methods
Exploratory case-control study investigating the relationship of gestational age at delivery to 31 single nucleotide polymorphisms measured in newborn screening bloodspots. Among all 443 children with later-diagnosed cerebral palsy born to white women in South Australia in 1986-1999, 234 were born after spontaneous onset of labor, and 108 of these were preterm (gestational age less than 37 weeks). The comparison group was 549 infants born after spontaneous onset of labor, of whom 147 were preterm. Distributions of genotypic frequencies were examined in preterm compared with term infants with and without cerebral palsy. Genotyping was performed using a Taqman assay.Results
In children without cerebral palsy, preterm birth after spontaneous onset of labor was more frequent in association with a variant of the beta2 adrenergic receptor gene (ADRB2 Q27E, P=.003), inducible nitric oxide synthase (iNOS or NOS2A, P=.042), or thrombomodulin (G127A, P=.006). Among children with cerebral palsy, preterm birth was associated with polymorphisms in genes for endothelial nitric oxide synthase (eNOS -922, P=.012), plasminogen activator inhibitor-2 (P=.015 and .019), and alpha adducin (ADD1, P=.047).Conclusion
We confirm previous observations that variants of the beta adrenergic receptor and of nitric oxide synthase are associated with prematurity, and suggest that genetic variants of the placental antifibrinolytic plasminogen activator inhibitor-2, and thrombomodulin and alpha adducin may be contributors to risk of spontaneous preterm birth.Level of evidence
II.Item Metadata only Genetic susceptibility to viral exposure may increase the risk of cerebral palsy(Blackwell Publishing Asia, 2009) Djukic, M.; Gibson, C.; MacLennan, A.; Goldwater, P.; Haan, E.; McMichael, G.; Priest, K.; Dekker, G.; Hague, W.; Chan, A.; Rudzki, Z.; van Essen, P.; Khong, T.; Morton, M.; Ranieri, E.; Scott, H.; Tapp, H.; Casey, G.Aim: Cytokine polymorphisms may alter the fetal inflammatory response, increasing susceptibility to cerebral palsy (CP). This study investigates associations between selected inflammatory mediator and cytokine gene polymorphisms (Toll-like receptor-4 (TLR-4) Asp299Gly, interleukin-6 G-174C and interleukin-4 C-589T) and CP from 443 CP infants and 883 control infants. Results were correlated with viral nucleic acids in the same samples. Results: At all gestational ages (GA), TLR-4 was associated with a decreased risk of developing CP (homozygous/heterozygous odds ratio (OR) 0.70, 95% confidence interval (CI) 0.50–0.98) and interleukin (IL)-6 was associated with an increased risk of developing hemiplegia (OR 1.38, 95% CI 1.05–1.83). For infants born 32–36 weeks GA, there was a tenfold increase in the risk of quadriplegic CP with homozygous/heterozygous IL-6 (OR 10.42, 95% CI 1.34–80.82). Viral exposure in combination with IL-4 in preterm infants was associated with a fourfold increased risk of quadriplegia (homozygous/heterozygous OR 4.25, 95% CI 1.21–14.95). In very preterm infants, the absence of detectable viral exposure in combination with IL-4 decreased the risk of developing CP (homozygous/heterozygous OR 0.31, 95% CI 0.13–0.76). Conclusion: Polymorphisms in TLR-4 may be associated with a decreased risk of CP. Polymorphisms in IL-6 or IL-4 may act as susceptibility genes, in the presence of viral exposure, for the development of hemiplegic and quadriplegic CP. These associations require confirmation but they suggest a hypothesis for CP causation due to double jeopardy from neurotropic viral exposure and genetic susceptibility to infection.Item Metadata only Mannose-binding lectin haplotypes may be associated with cerebral palsy only after perinatal viral exposure(Mosby Inc, 2008) Gibson, C.; MacLennan, A.; Goldwater, P.; Haan, E.; Priest, K.; Dekker, G.Objective The objective of the study was to investigate the associations between infection, polymorphisms in the mannose-binding lectin gene (MBL), and cerebral palsy (CP). Study Design This was a case-control study using deoxyribonucleic acid from newborn screening cards of 443 Caucasian CP cases and 883 Caucasian controls to screen for 6 polymorphisms within the MBL gene. These polymorphisms combine to create haplotypes with high (HYPA), intermediate (LYQA, LYPA), low (LXPA), and defective (HYPD, LYQC, LYPB) circulating MBL levels. Results χ² Analyses demonstrated significant differences between CP cases and controls (less than 37 weeks χ² 14.99, P = .02; less than 32 weeks χ² 13.62, P = .02). The MBL haplotype LYPA was associated with CP at all gestations (odds ratio [OR] 1.57, 95% confidence interval [CI], 1.00 to 2.46), less than 37 weeks (OR 2.43, 95% CI, 1.41 to 4.18), and less than 32 weeks (OR 2.54, 95% CI, 1.34 to 4.76). LYPA was also associated with hemiplegic CP for babies born at less than 37 weeks (OR 2.77, 95% CI, 1.02 to 7.26) and less than 32 weeks (OR 4.48, 95% CI, 1.55 to 12.65). HYPD was associated with quadriplegic CP at all gestations (OR 3.47, 95% CI, 1.41 to 8.31) as well as for babies born at less than 32 weeks (OR 7.86, 95% CI, 1.67 to 29.48). Subanalysis on samples previously testing positive for exposure to viral infection demonstrated similar patterns of significance as those presented above, whereas analysis on samples negative for exposure to viral infection showed no positive associations between any of the MBL haplotypes and CP. Potential type I error from multiple analyses is a caveat. Conclusion MBL haplotypes LYPA or HYPD may be associated with an increased risk of CP in the presence of exposure to viral infection and may act as susceptibility factors for CP.Item Open Access Neurotropic viruses and cerebral palsy: population based case-control study(British Med Journal Publ Group, 2006) Gibson, C.; MacLennan, A.; Goldwater, P.; Haan, E.; Priest, K.; Dekker, G.Objective: To investigate the association between cerebral palsy and direct evidence for perinatal exposure to neurotropic viruses. Design: Population based case-control study. Setting: Adelaide Women's and Children's Hospital Research Laboratory. Participants and main outcome measures: Newborn screening cards of 443 white case patients with cerebral palsy and 883 white controls were tested for viral nucleic acids from enteroviruses and herpes viruses by using polymerase chain reaction. Herpes group A viruses included herpes simplex viruses 1 and 2 (HSV-1 and HSV-2), Epstein-Barr virus (EBV), cytomegalovirus (CMV), and human herpes virus 8 (HHV-8), and herpes group B viruses included varicella zoster virus (VZV) and human herpes viruses 6 and 7 (HHV-6 and HHV-7). Results: The prevalence of viral nucleic acids in the control population was high: 39.8% of controls tested positive, and the prevalence was highest in preterm babies. The detection of herpes group B viral nucleic acids increased the risk of developing cerebral palsy (odds ratio 1.68, 95% confidence interval 1.09 to 2.59). Conclusions: Perinatal exposure to neurotropic viruses is associated with preterm delivery and cerebral palsy.Item Open Access Single-nucleotide polymorphism associations with preterm delivery: a case-control replication study and meta-analysis(Int Pediatric Research Foundation Inc, 2013) O'Callaghan, M.; MacLennan, A.; McMichael, G.; Haan, E.; Dekker, G.Background
The aim of this study was to replicate single-nucleotide polymorphism (SNP) associations with preterm birth (PTB; birth at <37 completed weeks of gestation) and synthesize currently available evidence using meta-analysis.Methods
Spontaneous PTB cases and controls were selected from an existing cohort. Candidate SNPs were taken from an existing genotype panel. A systematic review was conducted for each SNP in the panel to determine suitability as a PTB candidate. Those with significant associations previously reported in Caucasians were selected for replication. Candidate SNPs were already genotyped in cases and controls and clinical data were accessed from state perinatal and cerebral palsy databases. Association analysis was conducted between each SNP and PTB, and meta-analysis was conducted if there were ≥ 3 studies in the literature. Maternal and fetal SNPs were considered as separate candidates.Results
A cohort of 170 cases and 583 controls was formed. Eight SNPs from the original panel of genotyped SNPs were selected as PTB candidates and for replication on the basis of systematic literature review results. In our cohort, fetal factor V Leiden (FVL) was significantly associated with PTB (odds ratio (OR): 2.6, 95% confidence interval (CI): 1.31-5.17), and meta-analysis confirmed this association (OR: 2.71, 95% CI: 1.15-6.4).Conclusion
Replication and meta-analysis support an increased risk of PTB in Caucasians with the fetal FVL mutation.Item Open Access The antenatal causes of cerebral palsy - Genetic and viral associations(Cambridge University Press, 2008) Gibson, C.; MacLennan, A.; Goldwater, P.; Dekker, G.Cerebral palsy is the most common neurological disorder in children. Epidemiological evidence suggests that antenatal origins are a major cause. Currently there is no antenatal test for cerebral palsy, no proven preventable measures in late pregnancy, and no known cure. Cerebral palsy affects not only the diagnosed child, but also their family and the community, requiring considerable social and financial resources to assist these children in their daily lives.Item Metadata only The association between inherited cytokine polymorphisms and cerebral palsy(Mosby Inc, 2006) Gibson, C.; MacLennan, A.; Goldwater, P.; Haan, E.; Priest, K.; Dekker, G.; Hague, W.; Morton, M.Objective The purpose of this study was to investigate associations between inherited cytokine polymorphisms and cerebral palsy. Study design This was a case-control study that used DNA from the newborn infant screening cards of 443 white infants with cerebral palsy and 883 white control infants to test for the following cytokine polymorphisms: tumor necrosis factor–alpha-308, mannose-binding lectin–221, and 3 polymorphisms in exon-1 of the mannose-binding lectin gene at codon-52, -54, and -57. Results At all gestational ages mannose-binding lectin codon-54 increased the risk of the development of diplegia (homozygous or heterozygous odds ratio, 1.55; 95% CI, 1.03-2.32). For babies who were born at term, the risk of the development of quadriplegia was associated with heterozygous tumor necrosis factor– α (odds ratio, 1.82; 95% CI, 1.04-3.15), and mannose-binding lectin codon-54 was associated with diplegia (homozygous or heterozygous odds ratio, 2.12; 95% CI, 1.10-4.05). The presence of any polymorphism in mannose-binding lectin exon–1 at term approximately doubled the risk of the development of diplegia (odds ratio, 1.94; 95% CI, 1.05-3.62). Homozygous or heterozygous tumor necrosis factor– α was associated with hemiplegia for babies who were born at <32 weeks of gestation (odds ratio, 2.38; 95% CI, 1.02-5.58). Overall, the presence of any cytokine polymorphism was associated with cerebral palsy (odds ratio, 1.37; 95% CI, 1.02-1.84). Conclusion Carriage of polymorphisms in the tumor necrosis factor– α and mannose-binding lectin genes are associated with an increased risk of cerebral palsy.