Development and physical analysis of YAC contigs covering 5.7Mb of Xp22.3

• Main Author: Herrell, S.
• Published: University of Cambridge 1995
• Subjects: 616.042
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603978

A total of fifty eight YAC clones have been isolated from the region of Xp22.3 extending from the DXS404 locus to the DXS1145 locus. Restriction analysis of these clones in association with sequence tagged site (<I>STS</I>) contenting and end clone analysis has facilitated the construction of six contigs covering a total of 5.3 Mb in which sixteen potential CpG islands have been located within fifty seven of the YACs. The fifty eight YAC contains the DXS1145 locus and also a potential CpG island. Twenty four new <I>STSs</I> have been developed from probe and YAC end clone sequences and these have been used in the analysis of patients with deletions within Xp22.3 suffering from different combinations of the diseases chondrodysplasia punctata, mental retardation, X-linked icthyosis and Kallmann syndrome. The results suggest that (1) the gene for chondrodysplasia punctata must lie between the X chromosome pseudoautosomal boundary (PABX) and DXS1145; (2) a gene for mental retardation lies between DSX1145 and the <I>STS</I> GS1; and (3) the gene for ocular albinism type 1 lies proximal to the <I>STS</I> G13. The potential CpG islands within the YAC contigs constitute valuable markers for the possible positions of genes. Genes found associated with any of the potential CpG islands which lie within the deletion intervals defined above for the chondrodysplasia punctata and mental retardation genes would be possible candidates for these genes.