The data presented in this study are derived from the analyses of Notch mutants known to be associated with visible cytological deficiencies. One mutant, Df(l)Nfirb1, described as a right-side deficiency, bears a deletion that apparently initiates within the Notch locus and extends to the right as far as the locus of dm. Recombination experiments using heterozygotes of Df(1) Nfiebl with a serie...

Cytogenetic analysis was performed on short-term cultures of primary tumor samples from seven patients with posterior uveal melanoma. Informative data were obtained from four patients, all of whom had a near-diploid chromosomal number and clonal chromosomal alterations. Analysis of one patient's tumor revealed monosomy 3 as the only cytogenetically distinguishable aberration. Trisomies of chrom...

An asymmetric potato hybrid and its parental lines were cytogenetically examined. DAPI (4'-6-diamidino-2-phenylindole) staining was used to count chromosomes in all analysed lines and revealed the presence of minichromosomes in the hybrid genome. Fluorescent in situ hybridization (FISH) with rDNA sequence as a probe helped to determine the ploidy level of analysed lines and revealed that none o...

We describe a patient with acute myelomonocytic leukemia (AMML) in whom cytogenetic analysis revealed trisomy 4 associated with a ring chromosome. In addition, in a cytogenetically unrelated clone, trisomy 8 and 5q- abnormalities were detectable. The possibility of a subclinical myelodysplastic syndrome preceding the onset of AML is discussed on the basis of the morphological and cytogenetic fi...

Traditionally, monochorionicity has been regarded as synonymous with monozygosity. However, several recent cases of monochorionic dizygotic twins have shown that monochorionic twins can be dizygous. We report a rare case of monochorionic diamnionic, gender-discordant twins who were conceived spontaneously. Initially, a monochorionic placenta was diagnosed by ultrasonography at 8 weeks of gestat...

By cytogenetic and cytochemical analyses of individual hematopoietic colonies, we investigated clonality in progenitor compartments of primary acquired sideroblastic anemia (PASA). Two of our four subjects had reduced but countable numbers of CFU-E, BFU-E, and GFU-GM in methylcellulose culture. In one patient with cytogenetic abnormality of 47, XX, +8 in 67% of the bone marrow cells, cytogeneti...

BACKGROUND Childhood acute lymphoblastic leukemia (ALL) is characterized by recurrent genetic aberrations. The identification of those abnormalities is clinically important because they are considered significant risk-stratifying markers. AIMS There are insufficient data of cytogenetic profiles in Saudi Arabian patients with childhood ALL leukemia. We have examined a cohort of 110 cases of AL...

Acute lymphoblastic leukemia (ALL) in infants generally shows distinctive biologic features and has a poor prognosis. Cytogenetic studies indicate that many infant leukemias have chromosome 1 1 q23 translocations. Because of these findings and the distinct clinical features of infant leukemia, we investigated 30 cases of infant ALL for molecular defects of l l q23. Fourteen cases had cytogeneti...

PURPOSE To propose an alternative hypothesis for the observed differential survival of patients with small, medium, and large choroidal melanomas based on recently uncovered cytogenetic evidence about melanocytic choroidal tumors. METHODS Review and analysis of published data. RESULTS Recent evidence has shown that recurring nonrandom cytogenetic abnormalities are present within virtually a...

Telomeres are specialised nucleoproteic complexes localised at the physical ends of linear eukaryotic chromosomes that maintain their stability and integrity. In vertebrate chromosomes, the DNA component of telomeres is constituted by (TTAGGG)n repeats, which can be localised at the terminal regions of chromosomes (true telomeres) or at intrachromosomal sites (interstitial telomeric sequences o...