Number of "high genes" involved in determining the activity of paraoxonase.

The genetics of paraoxonase activity is further analysed on the basis of a Danish family material (Eiberg & Mohr 1981), namely a random sample of the investigated two mating types. The starting point is the earlier assumption that the segregation into high and low activity is due to alleles on a single locus with the frequency 0.726 of low genes (Eiberg & Mohr 1981, Nielsen et al. 1986). It is shown that a hypothesis of two "high genes", h1 and h2 on the same locus, with allele frequencies 0.117 and 0.157, both high genes being dominant over low genes and h2 dominant over h1, may explain the observed pattern of segregation. The hypothesis would imply average activities of genotype 1h1 of 960 microM PNP/1, of 1h2 1385 microM PNP/1, of h1h1 1202 microM PNP/1, and of h1h2 and h2h2 2048 microM PNP/1. It cannot be excluded that there are more than two "high genes". It is further shown that more than one "low gene" must be involved.