Heterogeneity of DNA and RNA in Hunter patients.

Genomic DNA and total RNA from lymphoblasts of nine unrelated Italian patients affected with Hunter syndrome were analyzed using a human cDNA clone coding for the lysosomal enzyme iduronate-2-sulphatase (IDS). Southern blot analysis resulted in patterns similar to the normal control for seven of the patients analyzed; an aberrant pattern was observed in two patients (F.N. and P.D.), suggesting deletions/rearrangement in the IDS gene. Northern blot analysis showed in seven patients, a pattern similar to the normal control; for patients F.N. and P.D. the pattern was atypical, i.e., normal RNA species were absent whereas two different transcripts occurred. These data confirm the heterogeneity of the molecular defects causing Hunter disease.