Molecular bases of metachromatic leukodystrophy in Polish patients.

Our preliminary studies on 43 unrelated Polish patients suffering from different types of metachromatic leukodystrophy (MLD) showed that four mutations in the ARSA gene accounted for 55% of mutated alleles (c.459+1G>A, p.P426L, p.I179S and c.1204+1G>A). Subsequently, we reported six additional mutations jointly accounting for 10% of mutated alleles. Further sequence analysis of the ARSA gene performed on DNA samples of Polish MLD patients with unidentified alleles revealed eight rare mutations on 10 alleles: p.R390W, p.E382K, p.R390Q, p.R288C, p.H397Y, p.F247S, p.D335V and g.561_562insC, responsible together for 12% of the examined alleles. We have not identified any frequent mutation in the ARSA gene, which would be typical or unique for Polish patients. In this report, we describe the results of this and summarize the results of this and our previous studies.