ARYLSULFATASE-A PSEUDODEFICIENCY - A COMMON POLYMORPHISM WHICH IS ASSOCIATED WITH A UNIQUE HAPLOTYPE

The allele for pseudodeficiency (PD) of the lysosomal enzyme arylsulfa tase A (ARSA) is a common polymorphism in all populations. The PD alle le frequency in different Israeli ethnic groups was found to range fro m 9.2-22.7%. The PD allele includes two different mutations PD(1) and PD(2) in an aproximatively 1 Kb interval. In this study we confirmed t hat while PD(1) may be found alone as a polymorphism, PD(2) is always associated with the PD allele (660 alleles screened). Analysis of thre e ARSA intragenic polymorphisms showed a complete linkage disequilibri um between the PD allele and an haplotype de fined by the three polymo rphic restriction sites. The results suggest that the origin of the PD polymorphism may be a common founder, or recurrent mutations which ar e occurring in a unique haplotype. (C) 1994 Wiley-Liss,Inc.