Surfactant protein A gene locus and respiratory distress syndrome in Finnish premature twin pairs.
BACKGROUND
Surfactant protein A (SP-A) polymorphisms are associated with susceptibility to respiratory distress syndrome (RDS). According to present hypothesis the association between SP-A polymorphisms and RDS may not be applicable to the entire population of premature infants.


OBJECTIVE
The present study was designed to evaluate the associations between SP-A allelic variants and RDS in a population consisting of 198 premature twin pairs.


METHODS
Genotype analysis of the SP-A1 and SP-A2 genes and twin zygosity definition were carried out.


RESULTS
The main SP-A1 allele 6A2 (P = 0.030), genotype 6A2/6A2 (P = 0.0042) and haplotype 6A2-1A(0) (P = 0.016) were over-represented in healthy premature twin infants compared to RDS twins. The homozygous genotype 6A2/6A2 was over-represented in twin pairs of whom both were healthy compared to twins concordant for RDS (odds ratio 0.18, confidence intervals 0.06-0.6, P = 0.0016) and born between 32 and 36 weeks. 6A2/6A2 was also overrepresented in healthy twin pairs with birth weight sum higher than the median (OR 0.15, CI 0.04-0.6, P = 0.0025).


CONCLUSIONS
In twins, the association between SP-A polymorphism and RDS is different from that seen in premature singleton infants. The factor associated with SP-A genotype-specific susceptibility to RDS appears to be related to the size of uterus and the length of gestation at birth.
Marttila
Riitta
R
Central Hospital of Southern Ostrobothnia, Seinäjoki, Finland.
Haataja
Ritva
R
Rämet
Mika
M
Pokela
Marja-Leena
ML
Tammela
Outi
O
Hallman
Mikko
M
D016000:Cluster Analysis; D005260:Female; D005387:Finland; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D014644:Genetic Variation; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D016015:Logistic Models; D008297:Male; D011110:Polymorphism, Genetic / Q000235:genetics*; D037662:Pulmonary Surfactant-Associated Protein A / Q000235:genetics*; D012127:Respiratory Distress Syndrome, Newborn / Q000235:genetics* / Q000473:pathology; D014599:Uterus / Q000473:pathology*
D037662:Pulmonary Surfactant-Associated Protein A