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We report on a 30-year-old man with azoospermia, primary hypogonadism and minor dysmorphic features who carried a balanced insertional chromosome translocation inv ins (2p24;4q28.3q31.22) de novo. Molecular cytogenetic analyses of the chromosome breakpoints revealed the localization of the breakpoint in 4q28.3 between BACs RP11-143E9 and RP11-285A15, an interval that harbours the PCDH10 gene. In 4q31.22, a breakpoint-spanning clone (RP11-6L6) was identified which contains the genes LSM6 and SLC10A7. On chromosome 2, BACs RP11-531P14 and RP11-360O18 flank the breakpoint in 2p24, a region void of known genes. In conclusion, the chromosome aberration of this patient suggests a gene locus for primary hypogonadism in 2p24, 4q28.3 or 4q31.2, and three possible candidate genes ( LSM6, SLC10A7 and PCDH10) were identified by breakpoint analyses. [ABSTRACT FROM AUTHOR]

The by‐product from vinyl chloride production, EDC‐tar, is a complex mixture of mainly short‐chained chlorinated aliphatic hydrocarbons. This mixture has been tested for mutagenicity by means of Ames’ Salmonella/mammalian microsome method. Since most of the components in the tar are poorly soluble in water, three agents were used as solvents or emulsifier: ethanol, DMSO, and Tween 80. The results with all these agents showed that EDC‐tar contains direct as well as indirect mutagenic constituents. It could be concluded that the mutagenic effect observed in the test could not be due to any significant extent to one of the main components, ethylene dichloride (1,2‐dichloroethane). This substance showed a weak mutagenic effect, but only at higher concentrations than could be available in the highest concentration tested of the tar. Although the microsomal system enhanced the mutagenicity both of the EDC‐tar and of 1,2‐dichloroethane, this enhancement was dependent on NADPH in the case of EDC‐tar but independent of NADPH with 1,2‐dichloroethane. The Salmonella/mammalian microsome method seems to be a suitable tool for both mutagenicity screening of complex chemical mixtures and identification of mutagenic constituents in such mixtures. [ABSTRACT FROM PUBLISHER]

Small supernumerary marker chromosomes (sSMC) are still a major problem in clinical cytogenetics as they are too small to be characterized for their chromosomal origin by traditional banding techniques, but require molecular cytogenetic techniques for their identification. Apart from the correlation of about one third of the sSMC cases with a specific clinical picture, i.e. the i(18p), der(22), i(12p) (Pallister Killian syndrome) and inv dup(22) (cat-eye) syndromes, most of the remaining sSMC have not yet been correlated with clinical syndromes. Recently, we reviewed the available >1600 sSMC cases (Liehr T, sSMC homepage: http://mti-n.mti.uni-jena.de/∼huwww/MOL_ZYTO/sSMC.htm). A total of 387 cases (including the 45 new cases reported here) have been molecularly cytogenetically characterized with regard to their chromosomal origin, the presence of euchromatin, heterochromatin and satellite material. Based on analysis of these cases we present the first draft of a basic genotype-phenotype correlation for sSMC for all human chromosomes apart from the chromosomes Y, 10, 11 and 13. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]