Placental and germ cell alkaline phosphatase RFLPs and haplotypes associated with spontaneous abortion.

Placental alkaline phosphatase (PLAP) and germ cell alkaline phosphatase (GCAP) are controlled by closely linked genes on chromosome 2q34-q37. In previous investigations, associations have been found between PLAP types and spontaneous abortion. In this study, PLAP and GCAP RFLPs and haplotypes were found to show highly significant associations with spontaneous abortions in the Finnish and Swedish populations. However, different associations were found in the Finnish and Swedish populations. The Finnish abortions were associated with the GCAP allele PstI(b) 2 and the Swedish abortions with the PLAP allele PstI(a) 2. A possible mechanism behind the associations may therefore be linkage disequilibria with deleterious alleles within or close to the alkaline phosphatase gene complex.