Factor V Leiden mutation: a contributory factor for cerebral palsy?

Systematic review: hereditary thrombophilia associated to pediatric strokes and cerebral palsy

OBJECTIVES

This review aimed to organize and consolidate the latest knowledge about mutations and genetic polymorphisms related to hereditary thrombophilia and their potential association with pediatric stroke and cerebral palsy (CP).

SOURCES

Scientific articles published from 1993 to 2013, written in Portuguese, English, French, and Spanish, were selected and reviewed. The publications were searched in electronic databases, and also in the collections of local libraries. The terms "hereditary thrombophilia", "polymorphisms", "mutation", "pediatric strokes", and "cerebral palsy" were used for the research.

SUMMARY OF THE FINDINGS

The search in databases and in the bibliographic references retrieved 75 articles for inclusion in this review. Studies that investigated hereditary thrombophilias and their associations to CP and arterial and venous pediatric stroke presented contradictory results. The meta-analysis and case-control studies that showed positive results for this association described only slightly increased relative risks and sometimes had questionable conclusions. The association of two or more hereditary thrombophilias, or the association between thrombophilia and other specific clinical risk factors, suggest a higher risk of CP and pediatric stroke than isolated hereditary thrombophilia.

CONCLUSIONS

Larger, multicenter studies should be developed in order to elucidate the role of mutations leading to hereditary thrombophilia and the development of CP and pediatric stroke. The complex and multifactorial etiology of CP and stroke makes this an arduous and difficult task; however, the benefits generated by these studies are immeasurable.

Fetal and maternal candidate single nucleotide polymorphism associations with cerebral palsy: a case-control study

OBJECTIVE

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.

The Australian cerebral palsy research study--protocol for a national collaborative study investigating genomic and clinical associations with cerebral palsy

AIM

Previous studies have proposed a link between the presence of specific single nucleotide polymorphisms (SNPs) and cerebral palsy and the majority of these associations remain to be confirmed or rejected by prospective studies with sufficient statistical power. Prior studies have also given little attention to the interaction of genomic characteristics and clinical risk factors.

METHODS

This paper describes the design of a prospective case-control study to test these genetic associations in conjunction with more stringent data collection in respect to clinical features associated with pregnancy, particularly maternal infection. Here we consider the ethical requirements, our hypothesis that genetic susceptibility modifies the risk of cerebral palsy in the presence of perinatal environmental triggers, a priori primary and secondary aims, power calculations, participant recruitment strategies, data linkage, sampling methods of genetic material and subsequent SNP analysis, collection of clinical data and the proposed final statistical analysis.

The genomic basis of cerebral palsy: a HuGE systematic literature review

Cerebral palsy has been associated with a number of candidate genes. To date, no systematic review has been conducted to synthesise genetic polymorphism associations with cerebral palsy. We apply the HuGE NET guidelines to search PubMed and EMBASE databases for publications investigating single nucleotide polymorphisms (SNPs) and cerebral palsy outcome. 22 papers were identified and are discussed in this review. Candidate genes were grouped as (1) thrombophilic, (2) cytokine, (3) apolipoprotein E or (4) other SNPs, largely related to cardiovascular physiology/pathophysiology and the functioning of the immune system. Of the studies identified, cohorts were usually small, without adequate control and ethnically diverse, making direct comparison between studies difficult. The most promising candidate genes include factor V Leiden, methylenetetrahydrofolate reductase, lymphotoxin-alpha, tumour necrosis factor-alpha, eNOS and mannose binding lectin. Large case-control studies are needed to confirm these candidates with attention given to cohort ethnicity, cerebral palsy subtype analysis and possible multiple gene and gene-environment interactions.

Antioxidant therapy and neuroprotection in the newborn

Injury to the perinatal brain is a leading cause of childhood mortality and lifelong disability. Despite recent improvements in neonatal care, no effective treatment for perinatal brain lesions is available. The newborn, especially if preterm, is highly prone to oxidative stress (OS) and to the toxic effect of free radicals (FRs). At birth, the newborn is exposed to a relatively hyperoxic environment caused by an increased oxygen bioavailability with greatly enhanced generation of FRs. Additional sources (e.g., inflammation, hypoxia, ischemia, glutamate and free iron release) occur, magnifying OS. In the preterm baby, the perinatal transition is accompanied by the immaturity of the antioxidant systems and the reduced ability to induce efficient homeostatic mechanisms designed to control overproduction of cell-damaging FRs. Improved understanding of the pathophysiological mechanism involved in perinatal brain lesions helps to identify potential targets for neuroprotective interventions, and the knowledge of these mechanisms has enabled scientists to develop new therapeutic strategies that have confirmed their neuroprotective effects in animal studies. Considering the growing role of OS in preterm newborn morbidity in respect to the higher risk of FR damage in these babies, erythropoietin, allopurinol, melatonin and hypothermia demonstrate great promise as potential neuroprotectans. This article provides an overview of the pathogenesis of FR-mediated diseases of the newborn and the antioxidant strategies now tested in order to reduce OS and its damaging effects.

Genetics considerations in cerebral palsy

Cerebral palsy refers to a collective of neurologic conditions that share in common disorders of motor function and posture. Traditionally, and still today in many circles, the term is considered almost synonymous with brain injury. Multiple lines of evidence, however, point to the fact that cerebral palsy is rarely caused by problems with perinatal management. In fact, a mounting body of evidence points to strong genetic influences on the occurrence of cerebral palsy. Like most neurogenetic conditions, cerebral palsy exhibits complex inheritance. The best descriptor of the inheritance of cerebral palsy would be that of "multifactorial inheritance." This implies etiologic and genetic heterogeneity with complex interactions with multiple environmental influences. This article reviews known genetic influences on the origin of cerebral palsy. A proposed scheme for the genetic evaluation in identifying the etiology of cerebral palsy is provided.

Space-Time Clustering Analyses of Occurrence of Cerebral Palsy in Northern England for Births 1991 to 2003

PURPOSE

The etiology of congenital cerebral palsy is unclear. Recent studies have suggested that maternal infection is involved. Indirect, but supportive, evidence for an infectious hypothesis would be provided by the finding of space-time clustering.

METHODS

We analyzed all 906 cases born during the period 1991-2003 using a population-based registry from Northern England. We applied the K-function method for testing global space-time clustering and used residential addresses at the time of birth. The Knox method was used to determine the spatio-temporal range over which global clustering occurred. Tests were repeated using nearest neighbor thresholds to allow for variable population density. Additionally, Kulldorff's scan statistic identified specific space-time clusters.

RESULTS

There was statistically significant evidence of global space-time clustering (p <or= 0.05). Clustering occurred over a range of close distances, but was most pronounced for cases born within 1-4 months of one another. A specific space-time cluster was identified during 1994.

CONCLUSIONS

The application of spatial statistics for the study of cerebral palsy is novel. There is tentative evidence for the involvement of spatially and temporally varying environmental etiological factors. These findings may support a role for infections or similar agents. However, the role of chance cannot be excluded.

The child with cerebral palsy: diagnosis and beyond

Cerebral palsy (CP) is one of the most common conditions we follow in our pediatric neurology offices. This review will hopefully convince you that the care of children with CP extends far beyond the diagnosis. The review addresses issues surrounding diagnosis, coimpairments, prognosis, and family-centeredness of care. It will also deal with routine office follow-up to prevent or identify complications, management of spasticity and other morbidities, alternative and complementary therapies, and finally transition.