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Biomedical subjects

N Rizzi

Publications and source records attributed to N Rizzi.

13 recordsLinked to original sources
PubMed1997

Cytogenetic study of pituitary adenomas.

We report the results of cytogenetic studies on 23 pituitary adenoma specimens, using both the direct and short-term tissue culture methods. The direct method was applied to all of the specimens and allowed a karyotype to be identified in 15 of the processed samples (65%). Four tumors were shown to have a hypotriploid chromosomal constitution, two of which also presented structural clonal rearrangements: an isochromosome 1q,i(1)(q10) and a der(1)t(1;3)(p22;q21) were observed in two PRL-secreting adenomas, one of which also had a telomeric association involving the short arms of chromosomes 14 and 19. Telomeric associations of the long arms of chromosomes 11, 19, and 22 were observed in a near-diploid, non-secreting tumor showing monosomy 13. One other adenoma showed trisomies 8 and 12, a finding that was confirmed by means of the FISH analysis of chromosome 8 and 12 centromeric probes in the more than 300 scored nuclei. An apparently normal chromosome constitution was observed in the remaining nine cases. Short-term cultures were set up in 21 of the 23 samples, allowing us to obtain a karyotype in 18 specimens (85%). The six tumors that could not be analyzed using the direct method showed a normal karyotype. A diploid chromosome constitution was observed in the four tumors shown to be hypotriploid by the direct method as well as in the tumor with monosomy 13. The trisomies 8 and 12 identified by the direct method in one tumor were still observed, but a clone with a normal karyotype was also found. To the best of our knowledge, this is the only report of the results of cytogenetic studies on pituitary adenomas performed using both direct preparation and short-term culture.

Adenoma↗
PubMed1997

FISH characterization of small supernumerary marker chromosomes in two Prader-Willi patients.

A small supernumerary chromosome was observed in two Prader-Willi syndrome (PWS) patients. The clinical diagnosis of PWS was confirmed by the ascertainment of the deletion of region 15q11-13 in one case and uniparental disomy (UPD) of the same region in the other. The markers were negative for dystamycinA/DAPI banding, did not contain NOR-positive satellites, and had an appearance consistent with a very small ring chromosome. Fluorescent in situ hybridization (FISH) analysis with the "all human centromere" probe indicated the presence of centromeric sequences in both markers. Chromosomal in situ suppression hybridization with chromosome specific libraries demonstrated that the small markers in the deleted and UPD patient originated from chromosome 15 and X, respectively. To the best of our knowledge these are the only PWS patients reported with a supernumerary marker chromosome other than inv dup(15) characterized by FISH.

Adolescent↗
PubMed1996

Isochromosome 15q of maternal origin in a Prader-Willi patient with pituitary adenoma.

We report on a Prader-Willi syndrome (PWS) patient carrier of a balanced 15q15q translocation and affected by a prolactin-secreting pituitary adenoma. Evidence provided by molecular studies indicates that the structural rearrangement is an isochromosome of maternal origin. According to the identification of isodisomy as the basis of the association of rare disorders and the recent report on chromosome 15 monosomy and nullisomy in pituitary adenoma, we suggest that in our case PWS and pituitary adenoma might be related.

Adenoma↗
PubMed1995

FISH analysis in Prader-Willi and Angelman syndrome patients.

We report on a combined high resolution cytogenetic and fluorescent in situ hybridization study (FISH) on 15 Prader-Willi syndrome (PWS) and 14 Angelman syndrome (AS) patients. High resolution banding showed a microdeletion in the 15q11-q13 region in 7 out of 15 PWS patients, and FISH analysis of the D15S11 and SNRPN cosmids demonstrated absence of the critical region in three additional cases. Likewise 8 out of 14 AS patients were found to be deleted with FISH, using the GABRB3 specific cosmid, whereas only 4 of them had a cytogenetically detectable deletion.

Angelman Syndrome↗
PubMed1994

Familial translocation (X;3) (p22.3;p23): chromosomal in situ suppression (CISS) hybridization and inactivation pattern study.

High-resolution chromosome banding and chromosomal in situ suppression hybridization were used to identify a derivative X in a 10-month-old female patient with congenital heart defect and slight dysmorphism. The unbalanced karyotype was monosomic for Xp22.3-pter and trisomic for 3p23-pter regions. The derivative X was inherited from the mother carrier of a balanced translocation (X;3) (p22.3;p23). Replication study of the patient showed the abnormal X,t(X;3) to be late replicating, except for the translocated segment. This patient demonstrated only epicanthus and congenital heart defect, despite her partial trisomy 3. The clinical phenotype may be less severe when the X-chromosome is involved in an unbalanced translocation.

Adult↗
PubMed1994

A de novo 6q11-q15 duplication investigated by chromosome painting.

A de novo interstitial duplication of the 6q11-q15 chromosome region, confirmed by the application of a chromosome 6 painting probe, was observed in a patient with craniofacial dysmorphism, psychomotor retardation, cryptorchidism and hypospadias. Despite the publication of several cases showing partial trisomy 6q, to our knowledge the duplication of the proximal region q11-q15 has not previously been reported.

Adolescent↗
PubMed1993

Cytogenetic abnormalities detected by direct analysis in a case of choriocarcinoma.

Malignant trophoblastic cells from a case of choriocarcinoma were cytogenetically investigated by direct analysis of fresh tissue from the tumor. To our knowledge, previous cytogenetic studies have been performed only on established cell lines. In this study, 54 metaphases were observed, of which 41 were fully karyotyped. Three chromosomally abnormal lines were identified. In all of them, trisomy 3 and 10, a supernumerary isochromosome 1q,i(1)(q10), an i(8)(q10) replacing one chromosome 8, and a marker chromosome were observed. In addition, involvement of chromosome 12 was observed in two of the three lines, trisomic in one and an i(12)(q10) in the other.

Choriocarcinoma↗