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M G Tibiletti

Publications and source records attributed to M G Tibiletti.

50 records · Page 3Linked to original sources
PubMed1993

'Late' chorionic villus sampling: cytogenetic aspects.

Cytogenetic data about 145 chorionic villus samples obtained between the 13th and 35th week of gestation are reported. 'Late' chorionic villus sampling (CVS) was used to resolve different situations: failed amniotic fluid cell cultures (5 cases); confirmation of an abnormal karyotype, previously diagnosed as mosaic (14 cases); and ultrasound fetal malformation (23 cases). Most of the samples (103 cases) were analysed for the classical indications and in these cases, the principal aim was to obtain a rapid fetal karyotype. Excluding the cases used to check fetal karyotype, a chromosomal aberration was found in 11 out of 131 biopsies. In four cases of the group in which the fetal karyotype was checked (14 cases), the pathology observed at the first diagnosis was confirmed, while in the remaining ten cases the anomaly was not observed.

Chorionic Villi Sampling↗
PubMed1993

Prenatal diagnosis of an extranumerary i(22p) with normal phenotype.

A DA-Dapi and AgNOR-negative extranumerary chromosome was identified prenatally in a male fetus and also found in his normal father. Fluorescence in situ hybridization using repetitive DNA probes showed that the minute marker was positive at both ends for beta-satellite sequences, while its centromere was recognized by a 22 alphoid probe. It is concluded that the non-mosaic familial marker represents a 22p isochromosome.

Adult↗
PubMed1993

Morphology and nuclear contents in IVF embryos.

Human pre-embryos, at 2-8 cells, with different morphology have been examined for chromosome constitution. Concerning the informative pre-embryos (23/65), 11 showed a normal karyotype and in 12 an abnormal karyotype was observed; there was not a complete correspondence between pronucleation and chromosome set. Also in the interphasic pre-embryos the presence of chromatin masses at different sizes was revealed. The observation of polyploid and/or polynucleated blastomeres can suggest a failure of synchronization between cytoplasmatic and nuclear division. Mosaicism, polyploidy and polynucleation are phenomena that could be caused by in vitro culture conditions or dependent upon the genetic anomaly of the zygote.

Blastocyst↗
PubMed1992

Different phenotypes in two cases of an apparently identical familial (Yq;13p) translocation.

A chromosome 13 with extra material on the short arm was observed in a 17-year-old boy showing defects in skeletal growth, an altered hormone profile and asthenoteratozoospermia, and in a 46 XX fetus subjected to prenatal diagnosis. The abnormal chromosome 13 had been transmitted from phenotypically normal parents who were the mother (case 1) and the father (case 2). The extra material on the abnormal chromosome 13 was brightly fluorescent after Q-banding, and positive in C-banding (CBG) and distamycin A-Dapi (DA-Dapi) banding. Staining of the nucleolus organizer region indicated its retention. In-situ hybridization of a Yq-specific repetitive DNA probe to chromosomal spreads from both cases demonstrated that the der(13) chromosome contains sequences of the Yq heterochromatic region. However, the apparently identical unbalanced (Y;13) translocation may either interfere (case 1) or not (father of case 2) with meiotic or postmeiotic sperm cell development.

Adolescent↗
PubMed1986

Technical aspects and diagnostic problems of direct chromosome analysis using chorionic villus sampling in the first trimester.

This paper describes 18 months' experience of direct chromosome analysis applied to villi aspirated during the first trimester, using a catheter inserted trans-cervically. A total of 325 biopsy samples were analysed, and there was a diagnostic failure in 6 of these cases (1.8%). An abnormal karyotype was detected in 12 cases (3.8%); three of them were chromosome mosaics not confirmed on amniotic fluid cultures drawn between the 16th and 18th week of gestation. Cytogenetic control was performed on fetal tissues after voluntary abortion. There was a karyotype discrepancy between the placenta and the fetus in two cases out of the 12 mentioned above.

Adult↗
PubMed1983

Routine chromosome analysis on fetal blood microaliquots obtained at fetoscopy.

A routine study of the fetal karyotype was performed on samples obtained at 64 fetoscopic procedures. In 13 cases only pure amniotic fluid was available for the cultures, while in the remaining 51 cases the chromosome analysis was carried out on PHA-stimulated lymphocyte microcultures set up with any excess fetal blood above the requirements for globin-chain synthesis. Karyotype could be determined on fetal lymphocytes in 44 cases (86 per cent). All the fetuses were chromosomally normal. This experience shows that cytogenetic analysis using microaliquots of fetal blood is a relatively simple technique which should be introduced into routine prenatal diagnosis by fetoscopy.

Amniotic Fluid↗
PubMed1983

SCE analysis in children exposed to lead emission from a smelting plant.

The frequency and location of SCE were evaluated in lymphocytes from peripheral blood cultures of 19 children living in a widely contaminated area and showing an increased absorption of lead. In the comparison between the exposed children and a control group living in an uncontaminated area, no significant differences were found in the mean values of SCE frequencies. The distributions of the SCE between chromosomes were proportional to chromosome length in both groups.

Adolescent↗
PubMed1982

Cytogenetic findings in 4952 prenatal diagnoses. An Italian collaborative study.

The development of prenatal diagnosis in Italy was made difficult by the restrictions of the old abortion law and only in recent years has a consistent number of cases been investigated. We report the experience on prenatal chromosome diagnosis of ten Italian centers participating in a collaborative study on 4952 diagnoses performed from 1972 to 1980. The main indication groups were: advanced maternal age (2882 cases), previous child with chromosome anomaly from parents with normal karyotype (847 cases), and chromosome anomaly in one parent (97 cases). The other indications for amniocentesis, including cases without a cytogenetic risk, have been assembled into a "miscellaneous" group (1126 cases). We found 125 abnormal fetal karyotypes (2.5%) of which 89 were unbalanced (1.8%). The frequencies and types of chromosome anomalies are reported in detail for each indication group and are compared with the corresponding one from the European Munich Conference. The great majority of these Italian data were not included in the Munich report.

Chromosome Aberrations↗
PubMed1980

The offspring of marriage between two first cousins with the same reciprocal translocation t(2;7)(p11;q31).

A marriage between two first cousins who have the same 2/7 balanced translocation is reported. The chromosome rearrangement was primarily detected in amniotic fluid cells cultured for prenatal chromosome analysis because of advanced maternal age. The translocation was also found in the couple's two normal children and in three other members of the family. The possible zygotic chromosome constitutions following 2:2 meiotic segregation in consanguineous parents with the same translocation are discussed.

Adult↗
PubMedDate not supplied

Five cases of prenatally diagnosed sex chromosome mosaicism.

Prenatal detection of chromosome mosaicism is a relatively rare phenomenon and always constitutes a diagnostic problem. The difficulties are much more when the mosaics involve the sex chromosomes, because of the large phenotypic variability in individuals with these abnormalities. We studied 5 cases of true mosaics, 4 of these were prenatally detected, while 1 case was revealed only in the fetal lymphocytes after induced abortion. The limits of amniotic fluid culture with regard to the diagnosis of true mosaics and the difficulties arising in genetic counselling are discussed.

Adult↗
PubMedDate not supplied

Low incidence of hereditary nonpolyposis colorectal cancer syndrome in a selected area of the Lombardy Cancer Registry.

AIMS AND BACKGROUND: Epidemiological investigations on the frequency of hereditary nonpolyposis colorectal cancer (HNPCC) syndrome are few and have shown a variable worldwide incidence ranging from 1% to 7% of all colorectal cancers (CRCs). In Italy, relevant differences have been observed: 2.8-3% of all CRCs in northern regions and less than 1% in southern regions. The aim of the present study was to investigate the HNPCC incidence in a selected area of northern Italy belonging to the Lombardy Cancer Registry. METHODS AND STUDY DESIGN: We analyzed 197 consecutive patients with newly diagnosed CRCs, histologically verified, and resident in two areas of the Lombardy Cancer Registry. For each case, genetic counseling with at least three generations pedigree reconstruction, HNPCC classification according to Amsterdam criteria, molecular analysis for microsatellite instability and immunohistochemistry for hMLH1 and hMSH2 were performed. RESULTS: A very low frequency (0.5%) of HNPCC fulfilling the Amsterdam criteria was found in comparison to the other Italian areas. Such an incidence seems to be due to actual population differences and reflects a genetic heterogeneity. CONCLUSIONS: The data underline the importance of a precise knowledge of actual HNPCC incidence in different populations in order to optimize effectiveness and efficiency of screening programs for the disease.

Adult↗