Structure and sequence of the human α- l-fucosidase gene and pseudogene

Fucosidosis is a rare lysosomal storage disease resulting from a nearly complete deficiency of α- l-fucosidase enzyme activity. Previously, cDNA encoding human fucosidase was cloned and sequenced. Here we report the determination of the human fucosidase gene structure and sequence as well as the sequence of the fucosidase pseudogene. The gene encoding fucosidase is composed of eight exons spanning 23 kb of DNA. Analysis of the sequence 5′ of the open reading frame indicates the presence of multiple transcription factor binding sites but no TATA box. Northern blot analysis has confirmed an mRNA size of 2.3 kb in human lymphoblasts, testis, and epithelial cells. We have also sequenced the processed pseudogene of fucosidase. The sequence of the pseudogene is 80% identical to that of fucosidase cDNA but does not contain an open reading frame.