title: Familial and genetic susceptibility to major neonatal morbidities in preterm twins.
abstract: BACKGROUND
  Intraventricular hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia remain significant causes of morbidity and mortality in preterm newborns.
  
  
  OBJECTIVE
  Our goal was to assess the familial and genetic susceptibility to intraventricular hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia.
  
  
  METHODS
  Mixed-effects logistic-regression and latent variable probit model analysis were used to assess the contribution of several covariates in a multicenter retrospective study of 450 twin pairs born at < or =32 weeks of gestation. To determine the genetic contribution, concordance rates in a subset of 252 monozygotic and dizygotic twin pairs were compared.
  
  
  RESULTS
  The study population had a mean gestational age of 29 weeks and birth weight of 1286 g. After controlling for effects of covariates, the twin data showed that 41.3%, 51.9%, and 65.2%, respectively, of the variances in liability for intraventricular hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia could be accounted for by genetic and shared environmental factors. Among the 63 monozygotic twin pairs, the observed concordance for bronchopulmonary dysplasia was significantly higher than the expected concordance; 12 of 18 monozygotic twin pairs with > or =1 affected member had both members affected versus 3.69 expected. After controlling for covariates, genetic factors accounted for 53% of the variance in liability for bronchopulmonary dysplasia.
  
  
  CONCLUSIONS
  Twin analyses show that intraventricular hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia are familial in origin. These data demonstrate, for the first time, the significant genetic susceptibility for bronchopulmonary dysplasia in preterm infants.
authors.affiliation: Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520-8064, USA.
authors.forename: Vineet
authors.initials: V
authors.lastname: Bhandari
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Bizzarro
authors.forename: Anupama
authors.initials: A
authors.lastname: Shetty
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Zhong
authors.forename: Grier P
authors.initials: GP
authors.lastname: Page
authors.forename: Heping
authors.initials: H
authors.lastname: Zhang
authors.forename: Laura R
authors.initials: LR
authors.lastname: Ment
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Gruen
mesh_terms: D001997:Bronchopulmonary Dysplasia / Q000235:genetics*; D002543:Cerebral Hemorrhage / Q000235:genetics*; D004200:Diseases in Twins / Q000235:genetics*; D020345:Enterocolitis, Necrotizing / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000235:genetics*; D008297:Male; D012189:Retrospective Studies