Unbalanced 1q whole-arm translocation resulting in der(14)t(1;14)(q11-12;p11) in myelodysplastic syndrome.

Unbalanced whole-arm translocations (WATs) of the long arm of chromosome 1, resulting in complete trisomy 1q, are chromosomal abnormalities detectable in both solid tumors and hematologic neoplasms. Among the WATs of 1q to acrocentric chromosomes, a few patients with der(1;15) described as a dicentric chromosome have been reported so far, whereas cases of der(1;14) are much rarer. We report on a case of der(1;14) detected as single anomaly in a patient with myelodysplastic syndrome. The aim of our work was to investigate the breakpoints of the (1;14) translocation leading to the der(1;14). Fluorescence in situ hybridization (FISH) experiments have been performed on chromosome preparations from bone marrow aspirate, using specific centromeric probes of both chromosomes, as well as a probe mapping to 1q11 band. FISH results showed that in our patient the derivative chromosome was monocentric with a unique centromere derived from chromosome 14. The breakpoints of the translocation were located in the short arm of chromosome 14 and in the long arm of chromosome 1, between the alphoid D1Z5 and the satellite II domains. The 1q breakpoint was within the pericentromeric region of chromosome 1, which is notoriously an unstable chromosomal region, involved in different chromosomal rearrangements.

Identification of a mutant allele of the androgen receptor gene in a family with androgen insensitivity syndrome: detection of carriers and prenatal diagnosis.

We report the results of a molecular study of a large family segregating the complete form of the Androgen Insensitivity Syndrome (CAIS) in several family members from three generations. We identified the mutant allele by polymerase chain reaction (PCR) amplification of the short tandem repeat (CAG)n, highly polymorphic in the population, present in the first exon of the androgen receptor (AR) gene. In this family four different alleles were detected and one of these showed a perfect segregation with the disease. This study enabled us to identify the heterozygous females in this family. We think that this simple, indirect test, is also suitable for prenatal diagnosis of Morris' syndrome when the mother is heterozygous for the size of the short tandem repeat and one affected subject in the family may be studied.

Genotoxic effects of cadmium chloride on human amniotic fluid cells cultured in vitro.

In this study we report the results of cytogenetic tests, namely a search for chromosome aberrations (CA) and sister chromatid exchanges (SCEs), performed on human amniotic fluid cells cultured and treated with Cadmium chloride. The cells from primary cultures were exposed to CdCl2 at 1 microM and 10 microM for 24 h. At the higher dose, no metaphases were scored and at the lower dose (1 microM) no effects were evident on cell proliferation, and no chromosome aberrations were found. In the subsequent experiments we used cells from subcultures exposed to 1 microM and 5 microM CdCl2. At the 5 microM dose was evident the induction of chromatid breaks, while the frequency of sister chromatid exchanges shows a small increase, not statistically significant at the dose of 1 microM. In this study we positively demonstrated that amniotic fluid cells grown in vitro are reliable for testing various mutagenic or teratogenic substances. With regard to cadmium treatment results, it is evident a clastogenic effect of cadmium chloride but not a significant induction of SCEs.

Presence of telomeric and subtelomeric sequences at the fusion points of ring chromosomes indicates that the ring syndrome is caused by ring instability.

In situ hybridization of a telomeric (TTA-GGG)n sequence to metaphases from three cases of ring chromosome, involving respectively chromosomes 4, 16, and 20, showed the presence of the cognate sequences in all three rings. To investigate whether these ring chromosomes originated by telomere-telomere fusion, we determined, by in situ hybridization, whether telomere-associated sequences and/or specific distal sequences were still present in the ring chromosomes. The finding that these sequences were preserved in all the ring chromosomes strongly indicates that they originated by telomere-telomere fusion. All three subjects carrying the ring chromosomes are affected by the so-called ring syndrome, with failure to thrive, minor dysmorphic signs and no major anomalies. The r(4) patient has the ring in mosaic form with a normal cell line and has normal intelligence. The r(16) and the r(20) patients have moderate mental retardation and suffer from seizures. We conclude that the ring syndrome, even in its more severe manifestation, is caused by ring chromosome instability.

Graft-versus-leukemia effects after allogeneic bone marrow transplantation are active also in the presence of clones with chromosomal anomalies in addition to the Ph chromosome.

Two male patients with Philadelphia-chromosome (Ph+) chronic myelogenous leukemia (CML) underwent allogeneic bone marrow transplantation (ABMT) in the first chronic phase after busulfan treatment. In both cases, the donor was a sister, and engrafting was demonstrated by chromosome analyses which showed only donor cells in the BM. Cytogenetic relapse occurred 29 and 30 months after ABMT, respectively, when host cells reappeared: in both cases, the Ph and additional anomalies typical of the blastic phase of CML were evident. We then monitored the chromosome picture for 52 and 39 months, respectively: no striking evolution occurred, and cells with the Ph and additional anomalies persisted together with donor cells, which were a minority in the first patient and a great majority in the second throughout the observation period. A clinical relapse was observed in the first patient, but the disease never progressed to a blastic phase, whereas the second patient has not relapsed 7 years after ABMT. We reviewed data from the literature on cytogenetic relapse after ABMT in CML without clinical relapse, especially the 12 patients in whom cytogenetic relapse included chromosome anomalies in addition to the Ph, as in our patients. We suggest that graft-versus-leukemia (GVL) reactions in such patients are able to arrest progression of the leukemic blastic clone and prevent a possible relapse in blastic phase.

[Trisomy 18: phenotypic and biochemical variability]. / Trisomia 18: variabilità fenotipica e biochimica.

We report a case of Edward's syndrome showing some symptoms infrequently described in trisomy 18. The authors suggest that the phenotypic expression of symptoms rarely observed in the syndrome may be better interpreted as non specific consequence of the chromosomal imbalance, rather than directly related to genes on chromosome 18. A gene dosage effect for the enzyme Peptidase A, whose gene is mapped on chromosome 18, was also observed.

[The gene-dose effect for peptidase A on the erythrocytes of a patient with Edwards' syndrome]. / Effetto gene-dose per l'enzima peptidasi A su eritrociti di un paziente con sindrome di Edwards.

The study of gene/dosage effect may be essential in tracing the pathogenetic steps which lead from an unbalanced chromosome anomaly to a pathological phenotype. We present a newborn with a clinical and pathological picture compatible with a diagnosis of Edwards' syndrome. Chromosome analysis on lymphocytes and fibroblasts confirmed the diagnosis showing the presence of trisomy 18. On chromosome 18 the enzyme peptidase A is mapped, and we demonstrated the gene/dosage effect for Pep A in the erythrocytes of our patient.

[Gene-dosage effect of esterase D enzyme on erythrocytes in a patient with Patau's syndrome]. / Effetto gene-dose per l'enzima esterasi D su eritrociti di un paziente con sindrome di Patau.

The study of gene/dosage effect may be essential in tracing the pathogenetic steps which lead from an unbalanced chromosome anomaly to a pathological phenotype. We present a newborn with a clinical and pathological picture compatible with a diagnosis of Patau Syndrome. A chromosome analysis confirmed the diagnosis showing the presence of trisomy 13. On chromosome 13 the enzyme Esterase D (ESD) is mapped, and we demonstrated the gene/dosage effect for ESD in the erythrocytes of our patient.

Effect of microtubule inhibitors on the tubulin system of Dictyostelium discoideum.

Indirect immunofluorescence with antibodies to microtubular proteins has been used to investigate the microtubule system of Dictyostelium discoideum vegetative amoebae and the action of several compounds that interfere with that system. All the inhibitors tested show an antimicrotubular effect. Colchicine, vinblastine, nocodazole, thiabendazole, and isopropyl-N-phenyl-carbamate (IPC) seem to act mainly by destroying microtubules leaving the appearance of nuclei associated organelles (NAOs) undisturbed. On the other hand griseofulvin also affects NAOs which disappear in treated cells.