engleski

Localization of the Gorlin syndrome gene on 9q22

Several human genesincluding XPAC, FACC1, NBCCS(Gorlin syndrome)and ESS1 map to chromosome 9q22. Gorlin syndrome is an autosomal dominant disorder characterized by basal cell carcinomas, medulloblastomas and ovarian fibromas, as well as widespread developmental defects including pits of palms and soles, bifid ribs, spina bifida occulta and keratocysts of the jaws. Linkage and tumor deletion studies localized the gene for this syndrome on chromosome 9q22 between D9S196 and D9S180. Several groups have constructed YAC contigs of this region, but many of the YACs are known to contain rearrargements. PFGE and FISH were used to determine the order and distances in native DNA between 3 known genes, 3 STS and 5 anonymous cosmids from this region. D9S180, XPAC and 5 anonymous cosmids proximal to XPAC formed a group connected by comigrating fragments covering a region not larger than 1 Mb and not smaller than 500 kb. D9S196, FACC1 and D9S287 which are nelieved to lie proximal to this group did not show comigrating fragments with any other marker. Based on the largest fragments detected with these probes, the distance from D9S180 to D9S196 is not less than 2 Mb. Interphase FISH showed that Col15A1 lies approximately 100 kb distal to D9S180 and gave a distance between D9S196 and D9S180 of at least 2 Mb. Markers from this region have shown a high incidence of LOH in patients with Gorlin syndrome. LOH in both familial and sporadic tumours is consistent within the genetic localization of the NBCCS gene. The gene mapping to chromosome 9q22 acts probably as a tumor suppressor based on deletion studies of this region in many neoplasms related to the syndrome.

region 9q22; physical mapping; FISH; PFGE; polymorphic markers

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