Genome Center Reports on Gene Studies

The following four items were reported in Issue 14 (May 1995) of the Baylor Genome Center News.

Chondrodysplasia Punctata (CDPX) Region. Investigators with Andrea Ballabio [formerly at Baylor College of Medicine (BCM) and now at the Telethon Institute of Genetics and Medicine (Milan)] have cloned the genomic region on the X chromosome where the gene for X-linked CDPX is assigned. From this region three adjacent genes, presumed from their structure to have sulfatase activity, have been isolated. Chondrodysplasia is a congenital defect of bone and cartilage development characterized by aberrant bone mineralization, severe underdevelopment of nasal cartilage, and short finger ends. CDPX is also implicated in a similar disorder known as warfarin embryopathy, a condition caused by the administration of warfarin (an anticoagulant drug) during a critical 6- to 9-week period of pregnancy. [Cell 81, 15-25 (1995)]

X-Linked Ocular Albinism. Ballabio and Dick Lewis (BCM) have found an altered gene in the Xp22.3 region in patients with X-linked ocular albinism of the Nettleship-Falls type (OA1), a severe disorder affecting the eyes and the skin. [Nature Genetics 10, 13-19 (1995)]

Idiopathic Generalized Epilepsy (IGE). In searching for gene loci for IGE, Massimo Pandolfo, Pragna Patel, and coworkers at BCM and in Italy report that results of a study using nonparametric methods do not support linkage of IGE with chromosome 6 markers, as was suggested previously. Their results point to linkage to markers on the chromosome 8 long arm; this region is being investigated further in other IGE families. [Human Molecular Genetics 4, 1201-7 (1995)]

Spinocerebellar Ataxia Type 1. Studies by Huda Zoghbi (BCM) and collaborators show that both the normal and expanded versions of the SCA1 gene are translated and protein size is correlated with expansion size. Results showing that the proteins apparently have normal stability and distribution support the hypothesis of a novel harmful activity associated with the CAG coding region expansion.