Absence of the wild-type allele (192 base pairs) of a polymorphism in the promoter region of the IGF-I gene but not a polymorphism in the insulin gene variable number of tandem repeat locus is associated with accelerated weight gain in infancy.
OBJECTIVE
Our goal was to investigate whether a polymorphism in the insulin-like growth factor I promoter gene (IGF-I, wild-type, 192 base pairs) and in the insulin gene (INS) variable number of tandem repeat locus influence birth weight and weight gain in infancy.


METHODS
We obtained genomic DNA from 768 children. Exclusion criteria were multiple births, gestational diabetes, maternal diabetes, gestational age <37 weeks, >42 weeks, or unclear, and any condition potentially influencing weight gain. SD scores were calculated and adjusted for gestational age and gender. A gain in SD scores for weight between birth and 1 year >0.67 SD scores was defined as accelerated weight gain. Genotyping was performed by fragment length analysis (IGF-I) and by fragment length analysis after using a restriction enzyme-based assay (INS variable number tandem repeat).


RESULTS
Accelerated weight gain was present in 205 of 768 children. IGF-I and INS variable number tandem repeat genotype were not associated with birth weight. The IGF-I 192-base pair allele was less frequent in children with accelerated weight gain and was shown to reduce the risk for accelerated weight gain in a logistic regression model.


CONCLUSIONS
The IGF-I 192-base pair allele may reduce the risk for rapid weight gain in early infancy.
Landmann
Eva
E
Pediatric Center, Department of Pediatrics and Neonatology, Justus-Liebig-University Giessen, Feulgenstrasse 12, 35392 Giessen, Germany. eva.landmann@paediat.med.uni-giessen.de
Geller
Frank
F
Schilling
Jutta
J
Rudloff
Silvia
S
Foeller-Gaudier
Eleonore
E
Gortner
Ludwig
L
D000483:Alleles; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007328:Insulin / Q000235:genetics*; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D008297:Male; D018598:Minisatellite Repeats / Q000235:genetics*; D011110:Polymorphism, Genetic; D013997:Time Factors; D015430:Weight Gain / Q000235:genetics*
D007328:Insulin; D007334:Insulin-Like Growth Factor I