The human homologue of the murine Llglh gene (LLGL) maps within the Smith-Magenis syndrome region in 17p11.2.

We have isolated and characterized the human homologue of the murine Llglh gene, which was originally isolated as a homologue of a Drosophila tumor suppressor gene 1(2)gl (lethal(2) giant larvae). In the mouse, Llglh is thought to play an important role during brain development as a regulatory target of Hoxc8. The human homologue of Llglh (LLGL) encodes a protein consisting of 1,033 amino acids. This gene was mapped by fluorescence in situ hybridization (FISH) to human chromosome 17p11.2, a region that is typically deleted in patients with Smith-Magenis syndrome (SMS). In our FISH analysis of metaphase chromosomes of four SMS patients, a probe representing LLGL failed in each case to hybridize to one of the two chromosome 17 homologues, indicating that this gene may play a role in the pathogenesis of SMS.