We have performed molecular and mutation analyses on 14 unrelated Israeli Hunter families and have identified the IDS mutation in 8 of them. Three unrelated Ashkenazi patients had the same previously reported mutation (1246 C-->T). Based on the haplotypes of the mutation-bearing chromosomes, we concluded that this is a recurrent mutation. In two patients, we identified a deletion spanning exons V-VII. Three novel mutations were observed in different patients: L410P, 717de14, and 244de13. In addition, the silent mutation (562 C-->T) was observed in one patient.