IDS gene-pseudogene exchange responsible for an intragenic deletion in a Hunter patient.
Hunter disease or mucopolysaccharidosis type II is an X-linked disease caused by the deficiency of the lysosomal enzyme iduronate-2-sulfatase (IDS). The IDS gene (24 kb) contains nine exons and has been completely sequenced. A pseudogene (IDS-2 locus) distal to the functional IDS gene has recently been identified. This work reports the characterization of IDS gene alterations in two severely affected patients. Patient 1 has a partial deletion that removes exons I to VI and extends about 200 kb upstream of the IDS gene. Patient 2 has an internal deletion of exons IV, V, VI, and VII, which results from an IDS gene-pseudogene exchange between highly homologous regions. In the rearranged gene, the junction intron contains pseudogene intron 3- and intron 7-related sequences. An interchromosomal recombination is probably the cause of this rearranged X chromosome.
Birot
A M
AM
Laboratoire de Biochimie Pédiatrique, Hôpital Debrousse, Lyon, France.
Bouton
O
O
Froissart
R
R
Maire
I
I
Bozon
D
D
D015321:Gene Rearrangement; D006801:Humans; D007066:Iduronate Sulfatase / Q000235:genetics*; D016532:Mucopolysaccharidosis II / Q000235:genetics*; D009154:Mutation; D016133:Polymerase Chain Reaction; D011544:Pseudogenes; D012333:RNA, Messenger / Q000235:genetics
D012333:RNA, Messenger; D007066:Iduronate Sulfatase