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The human ZIC3 gene has been mapped to Xq26.2, the visceral heterotaxy locus HTX1, and has been shown to be mutated in X-linked situs ambiguus and/or complex heart defects. We report on a female fetus with situs ambiguus, asplenia and corrected transposition of the great arteries, displaying a (X;21) translocation. The balanced state of the t(X;21)(q26;p13) was verified by FISH on metaphase chromosomes of the fetus using DOP-PCR products of the microdissected der(21) and Xq-subtelomere specific sequences, and by PRINS withß-satellite specific sequences. Examination with polymorphic markers flanking ZIC3 on DOP-PCR products of the microdissected der(21) chromosome evidenced that the complete copy of the ZIC3 gene was translocated to chromosome 21. Mutations in the fetal and parental ZIC3 genes were excluded by sequencing. Paternal origin of the der(X) and der(21) chromosomes was confirmed by use of polymorphic microsatellite markers from chromosome 21 and from the chromosomal region Xq26, respectively. X chromosome inactivation analysis using a PCR of a polymorphic (CAG)n repeat in the first exon of the androgen receptor gene showed a completely skewed X inactivation pattern with the paternal X as the active X chromosome, thus excluding functional disomy of distal Xq. A positional effect caused by the balanced (X;21) translocation may be responsible for functional nullisomy of ZIC3 and thus explain the situs and cardiac abnormalities in the fetus.European Journal of Human Genetics (2005) 13, 34-40. doi:10.1038/sj.ejhg.5201213 Published online 06 October 2004 [ABSTRACT FROM AUTHOR]

The frequency of deletion of short arm satellites has been examined in various populations. Four out of 2509 males in psychiatric institutions and prisons had Dps- or Gps- (1·6 per 1000), and five out of 6187 persons in the general population had Dps- or Gps- (0·8 per 1000). The difference is not significant. The segregation rate of the chromosome with lack of short arm satellite material did not deviate from unity in the few families where such calculations were possible. There was no increase in abortions or non-disjunction in the families with an acrocentric chromosome lacking short arm satellite material. The study indicates that the frequency of Dps- and Gps- in the population is between 0·5 and 1·0 per 1000 and that the lack of short arm satellite material is without any deleterious effect on phenotype. [ABSTRACT FROM PUBLISHER]

Friend murine leukemia virus (F-MuLV) induces leukemia by integration into the cellular genome, thereby changing the structure of expression of cellular oncogenes. Here we describe a new F-MuLV integration site Fre-2 isolated from splenic DNA of an erythroleukemic animal. This site has been found rearranged in 5 out of 63 additional tumors; however, no F-MuLV proviruses could be detected in the vicinity of the rearrangement sites in these 5 cases. The rearrangements represented closely clustered chromosomal breakpoints, presumably chromosomal translocations. Exons transcribed into differentially spliced mRNAs of 1.9 and 3.7 kb have been found near the breakpoint. No sequences that are homologous to Fre-2 could be found in databases. [ABSTRACT FROM AUTHOR]

The article discusses a case study of a patient with mental retardation in Turner's syndrome. Mental retardation is found more frequently in girls with Turner's syndrome than in normal's. Physical examination of a patient studied in this article at the age of twenty-six showed a 139 cm tall girl who weighed 45 kg. There was strabismus convergence of the left eye. The fifth fingers on both hands were smaller than usual. She has suffered from epilepsy since the age of three years. Neurological examination has shown normal conditions, except for atypical left plantar reflex. She is severely mentally retarded. Hand and foot prints showed some feature of Turner's syndrome. Quinacrine staining did not reveal the origin of the small acrocentric fragment, which was weakly fluorescing; it was most probably of autosomal origin representing a partial autosomal trisomy.

Presents a study which investigated case reports of patients with an additional acrocentric chromosomes and without symptoms of Down syndrome. Results of physical examination done on the patients; Radiological findings; Chromosome examination; Cause of the additional acrocentric chromosome; Comparison of the patients with those who have supernumerary small acrocentric chromosomes and no symptoms of Down syndrome.