Iduronidase knock-out mouse

A knock-out mouse comprising a disruption in the wild-type α-L-iduronidase gene,

• wherein said disruption has been introduced into its genome by homologous recombination with a DNA targeting construct in an embryonic stem cell such that the targeting construct is stably integrated in the genome of said mouse,
• wherein the disruption of the α-L-iduronidase gene results in an inability of said mouse to produce detectable levels of α-L-iduronidase;
• wherein the disruption of said α-L-iduronidase gene results in a 1150 bp deletion consisting of a second part of exon 6, all of exon 7, all of exon 8 and a first part of exon 9;
• wherein all of exons 1 to 5, a first part of exon 6, a second part of exon 9, and all of exons 10 to 14 are maintained in the genome;
• and
• wherein the first part of exon 6 comprises the 5′ end of exon 6, the second part of exon 6 comprises the 3′ end of exon 6, the first part of exon 9 comprises the 5′ end of exon 9, and the second part of exon 9 comprises the 3′ end of exon 9.