Population genetics of polymorphisms in Cardiff newborn. Relationship between blood group and allozyme heterozygosity and birth weight.

A newborn population of Cardiff, Wales, was screened for variation at three blood group loci (ABO, Rhesus and MN) and four enzyme loci (ACP-1, PGM-1, ADA and EST-D). Birth weights were measured. There were no significant differences between mean birth weights or birth weight variances for individuals homozygous or heterozygous at the MN and the four enzyme loci. (ABO and Rhesus loci cannot be used in these tests.) There was no significant heterogeneity in contingency tables relating phenotypes at the seven loci to birth weight. There were no significant differences in mean heterozygosity per locus between babies placed in different birth weight categories, ranging from 2.5 to 4.2 kg. The genetic variation screened appears therefore to be neutral with respect to this character.