Haloacid Dehalogenase Like Hydrolase Domain Containing Protein 1 (HDHD1)

The cDNA clone detected a 2.3-kb transcript in human placenta and fibroblasts and appeared to encode a protein of 214 amino acid residues. Although homologous sequences were found on chromosomes 1, 20, and Y, the functional gene was located on the X chromosome.

No clinical difference was detected between STS-deficient patients with point mutations in the STS gene and patients with a deletion of both the STS and the GS1 genes. The GS1 gene was expressed from mouse-human cell hybrids containing either active or inactive human X chromosomes, indicating that it escapes X inactivation. The chromosomal gene comprises 4 exons spanning over 105 kb, with its transcriptional direction opposite to that of the STS gene.