Association of the Growth Hormone Receptor d3-Variant and Catch-up Growth of Preterm Infants with Birth Weight of Less Than 1500 Grams

BACKGROUND: Preterm infants with very low birth weight frequently exhibit impaired longitudinal growth during the first years of life. Recently, the d3-isoform (genomic deletion of exon 3) of the GH receptor (GHR) has been linked to an increased responsiveness to GH. OBJECTIVE: Our objective was to test whether the GHRd3 isoform is associated with postnatal catch-up growth in very low birth weight preterm infants. DESIGN AND PATIENTS: We compared the postnatal growth pattern of 77 otherwise healthy preterm infants (mean gestational age, 28.5 wk; range, 23-35 wk) with a birth weight below 1500 g (mean birth weight, 941 g) to their GHR exon 3 genotype, which was analyzed by multiplex PCR. On examination, mean age of the children was 6.0 yr (range, 4.2-8.0 yr). RESULTS: Children homozygous or heterozygous for the GHRd3 allele showed a significantly higher rate of postnatal catch-up, compared with those homozygous for the full-length allele. CONCLUSIONS: Our results define the GHR exon 3 genotype as a predictor for the postnatal growth pattern of very low birth weight preterm infants. Those who carry at least one GHRd3 allele are more likely to catch-up.