Detection of a new Msp I restriction fragment length polymorphism in the apolipoprotein A-I gene.

We report the existence of a Msp I restriction fragment length polymorphism in the first intron of the apolipoprotein A-I gene that is different from the one described by Seilhamer et al. (DNA 3, 309 (1984)). Size comparison of the newly discovered Msp I fragment with a restriction map of the apolipoprotein A-I gene revealed that most likely the cutting site at the 5'-end of the normally seen 673 bp fragment is lost giving rise to the observed 719 bp Msp I fragment. Based on analyses of 136 DNAs of healthy and non-related caucasians the allelic frequency was determined to be 0.06. The observed Msp I genotype frequencies are in Hardy-Weinberg equilibrium.