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Trisomy 9 including mosaic and partial trisomy is less frequently seen chromosomal abnormality in live born children. The pure or partial trisomy 9 frequently been reported in prenatal diagnosis and product of conception. However few studies reported partial trisomy 9 in live born children. In addition data on genotype and phenotype correlation of partial trisomy is not well understood except few case reports. Here we report a case of partial trisomy 9 and monosomy 14 with a 46,XY,der(9)t(9;14)(q22.1;q11.2)pat,-14 karyotype in a 5-year old dysmorphic child. The proband was confirmed as trisomic for 9pter->9q22.1 and monosomic for 14pter->q11.2 due to paternal t(9;14)(q22.1;q11.2) balanced translocation using a combination of conventional and molecular cytogenetic (fluorescence in situ hybridization, array-comparative genomic hybridization) techniques. The clinical features similar to pure trisomy 9 is due to duplication of the large region of chromosome 9. However, the present report of partial trisomy 9 and monosomy 14 is a novel case report and showing comparatively longer survival which have not been previously reported in the literature. The parent of the proband was counseled for the future pregnancies.

Lipoblastoma-like tumor of the vulva was first described as a benign mesenchymal neoplasm of adipocytic differentiation having features of lipoblastoma, myxoid liposarcoma, and spindle cell lipoma. Prior studies of lipoblastoma-like tumor have evaluated PLAG1, HMGA2, and RB1 immunohistochemistry and DDIT3 rearrangement status, with results supporting its distinction from lipoblastoma and myxoid liposarcoma. However, absent RB1 expression was reported in a majority of tested cases, suggesting that lipoblastoma-like tumor may have underlying 13q alterations and be related to RB1-deleted soft tissue tumors. To further understand the molecular genetics of lipoblastoma-like tumor, we examined 7 cases by RB1 immunohistochemistry, DDIT3 and PLAG1 break apart FISH probes, RB1 enumeration FISH probe, and genomic copy number analysis by microarray. Patient age ranged from 21 to 56 years (median 35 years). Clinical follow up was available for 5 patients (71%) ranging 3-264 months (median 74 months). Microscopically, lipoblastoma-like tumor formed large lobules separated by thin and/or thick bands of fibrous tissue and had a prominent network of thin-walled vessels. Each tumor was predominantly composed of spindle cells and lipoblasts with variable quantities of mature adipocytes. RB1 immunohistochemistry exhibited a heterogeneous or "mosaic" pattern of weak and negative nuclear expression in all seven cases. DDIT3 and PLAG1 FISH were negative in each case. No evidence of RB1 regional gain or loss was identified by FISH. Genomic copy number analysis by chromosomal microarray showed a normal diploid profile in six tumors (86%). One tumor had copy number abnormalities consisting of an 11.9 megabase deletion from 1p13.3 to 1p11.2 and monosomy 14. Although lipoblastoma-like tumor has features of lipoblastoma, myxoid liposarcoma, and spindle cell lipoma, it is genetically different from these tumors. Furthermore, lipoblastoma-like tumor does not appear to have structural abnormalities of 13q resulting in deletion of RB1.

In this study, we report three paediatric cases of Diffuse Glioneuronal Tumours with Oligodendroglioma-like features and Nuclear Clusters (DGONC).

Aims: DNA methylation-based central nervous system (CNS) tumour classification has identified numerous molecularly distinct tumour types, and clinically relevant subgroups among known CNS tumour entities that were previously thought to represent homogeneous diseases. Our study aimed at characterizing a novel, molecularly defined variant of glioneuronal CNS tumour. Patients and methods: DNA methylation profiling was performed using the Infinium MethylationEPIC or 450 k BeadChip arrays (Illumina) and analysed using the ‘conumee’ package in R computing environment. Additional gene panel sequencing was also performed. Tumour samples were collected at the German Cancer Research Centre (DKFZ) and provided by multinational collaborators. Histological sections were also collected and independently reviewed. Results: Genome-wide DNA methylation data from >25 000 CNS tumours were screened for clusters separated from established DNA methylation classes, revealing a novel group comprising 31 tumours, mainly found in paediatric patients. This DNA methylation-defined variant of low-grade CNS tumours with glioneuronal differentiation displays recurrent monosomy 14, nuclear clusters within a morphology that is otherwise reminiscent of oligodendroglioma and other established entities with clear cell histology, and a lack of genetic alterations commonly observed in other (paediatric) glioneuronal entities. Conclusions: DNA methylation-based tumour classification is an objective method of assessing tumour origins, which may aid in diagnosis, especially for atypical cases. With increasing sample size, methylation analysis allows for the identification of rare, putative new tumour entities, which are currently not recognized by the WHO classification. Our study revealed the existence of a DNA methylation-defined class of low-grade glioneuronal tumours with recurrent monosomy 14, oligodendroglioma-like features and nuclear clusters.

Objective To review the literature for survival and phenotypes of liveborns with autosomal monosomy to inform decisions regarding transfer of in vitro fertilization-derived embryos reported as monosomic on preimplantation genetic testing for aneuploidy (PGT-A). Method Ovid-Medline and EMBASE were systematically searched to identify published case reports of liveborn individuals with autosomal monosomy, full or mosaic, for a whole chromosome. Results Fifty-three reports describing 56 individuals with autosomal monosomy met the selection criteria: 1 case each of monosomy 14 and 16, 3 each for monosomy 15 and 18, 1 for group “E”, 5 for monosomy 20, 24 for monosomy 21, 7 for monosomy 22, and eleven for a “G” group chromosome. There were no reports with monosomy for the larger chromosomes 1 through 13, nor for chromosomes 17 or 19, autosomes with highest gene density. Most reported individuals had severe handicaps and died in infancy with some surviving longer. Conclusion Given potential for survival of handicapped individuals with autosomal monosomy for chromosomes 14, 15, 16, 18, 20, 21, and 22, low priority should be given to transfer of embryos apparently monosomic for these chromosomes. Couples electing transfer of monosomic embryos should consider amniocentesis for ongoing pregnancies but should be informed of its limitations.

Sarcomas are rare uterine tumors with leiomyosarcomas and endometrial stromal sarcomas constituting the predominant entities often making their first appearance in young and middle-aged women. By histology combined with immunostaining alone some of these tumors can offer diagnostic challenges e.g. for the differential diagnosis between leiomyosarcomas and smooth muscle tumors of uncertain malignant potential (STUMP). Areas covered: Recent advances in the genetic classification and subclassification, respectively, have shown that genetic markers can offer a valuable adjunct to conventional diagnostic tools. Herein, we will review these recent data from the literature also referring to genetic alterations found in STUMP, endometrial stromal nodules, and leiomyomas including their variants. Expert commentary: For the future, we consider genetic classification as a necessary step in the clinical management of these tumors which will help not only to improve the diagnosis but also the therapy of these malignancies often associated with a worse prognosis.

Chromosome 14 loss in meningiomas are associated with more aggressive tumour behaviour. To date, no studies have been reported in which the entire chromosome 14q of meningioma tumour cells has been studied by high-resolution array comparative genomic hybridization (a-CGH). Here, we used a high-resolution a-CGH to define the exact localization and extent of numerical changes of chromosome 14 in meningioma patients. An array containing 807 bacterial artificial chromosome clones specific for chromosome 14q (average resolution of ∼130Kb) was constructed and applied to the study of 25 meningiomas in parallel to the confirmatory interphase fluorescence in situ hybridization (iFISH) analyses. Overall, abnormalities of chromosome 14q were detected in 10/25 cases (40%). Interestingly, in seven of these cases, loss of chromosome 14q32.3 was detected by iFISH and confirmed to correspond to monosomy 14 by a-CGH. In contrast, discrepant results were found between iFISH and a-CGH in the other three altered cases. In one patient, a diploid background was observed by iFISH, while monosomy 14 was identified by a-CGH. In the remaining two cases, which showed gains of the IGH gene by iFISH, a-CGH did not detected copy number changes in one case showing a tetraploid karyotype, while in the other tumour, varying genetic imbalances along the long arm of chromosome 14 were detected. In summary, here, we report for the first time, the high-resolution a-CGH profiles of chromosome 14q in meningiomas, confirming that monosomy 14 is the most frequent alteration associated with this chromosome; other numerical abnormalities being only sporadically detected., This work has been partially supported by grants from Consejería de Sanidad (44-05) Junta de Castilla y León (Valladolid, Spain; Fondo de Investigaciones Sanitarias (FIS/FEDER 06/0312 and RTICC RD06/0020/0035 from the Instituto de Salud Carlos III, Ministerio de Sanidad y Consumo, Madrid, Spain) and Fundación MMA (Madrid, Spain). MD Tabernero is supported by IECSCYL. AB Espinosa is supported by grant FI05/00266 from the Instituto de Salud Carlos III (Ministerio de Sanidad y Consumo, Madrid, Spain).

An 8-year-old female child with mental retardation (MR), multiple congenital anomalies (MCA) and irregular pigmentation was shown to have karyotypic mosaicism involving chromosome 14 abnormalities. Four cell lines were found in both peripheral blood lymphocytes and skin fibroblasts and were represented by: a normal karyotype, an isopseudodicentric 14q [iso psu dic(14)], a ring 14 [r(14)], and a monosomy 14 [mono(14)]. Our results are compared with reported cases involving multiple abnormalities of specific chromosomes. Karyotypic mosaicism of comparable chromosome 14 abnormalities is rare, with only one known previous case. Detailed analysis of karyotypic mosaicism of rare chromosomal abnormalities is essential to determine meaningful correlations with specific patterns of malformation.

Tumor recurrence is the major clinical complication in meningiomas, and its prediction in histologically benign/grade I tumors remains a challenge. In this study, we analyzed the prognostic value of specific chromosomal abnormalities and the genetic heterogeneity of the tumor, together with other clinicobiological disease features, for predicting early relapses in histologically benign/grade I meningiomas. A total of 149 consecutive histologically benign/grade I meningiomas in patients who underwent complete tumor resection were prospectively analyzed. Using interphase fluorescence in situ hybridization, we studied the prognostic impact of the abnormalities detected for 11 different chromosomes, together with other relevant clinicobiological and histopathological characteristics of the disease, on recurrence-free survival (RFS) at 2.5, 5, and 10 years. From the prognostic point of view, losses of chromosomes 9, 10, 14, and 18 and del(1p36) were associated with a shorter RFS at 2.5, 5, and 10 years. Similarly, histologically benign/grade I meningiomas showing coexistence of monosomy 14 and del(1p36) in the ancestral tumor cell clone displayed a higher frequency of early relapses. In fact, coexistence of -14 and del(1p36) in the ancestral tumor cell clone, together with tumor size, represented the best combination of independent prognostic factors for the identification of those patients with a high risk of an early relapse. Our results indicate that patients with large histologically benign/grade I meningiomas carrying monosomy 14 and del(1p36) in their ancestral tumor cell clone have a high probability of relapsing early after diagnostic surgery. These findings suggest the need for closer follow-up in this small group of patients.

In recent years important advances have been achieved in the understanding of the genetic abnormalities present in meningioma tumors and its association with the ontogeny and progression of these tumor. Accordingly, while the presence of monosomy 22/22q-, associated with mutation of the NF2, BAM22, RRP22, GAR22, MN1, SMARCB1, CLH22 and/or LARGE genes, is associated with neoplasic transformation, other alterations such us monosomy 14, del(1p), different chromosomal abnormalities localized at 9p, 10q and 17q and complex karyotypes are frequently related to tumor progression. From the clinical point of view, currently available information about the impact of the different cytogenetic abnormalities on disease behavior and patient outcome is still scanty; nevertheless, the presence of gains of chromosome 22 in the context of a hyperdiploid karyotype, as well as del(1p) and monosomy 14 have been associated with a statistically significantly shorter recurrence-free survival, this later abnormality showing an independent prognostic value.

In multiple myeloma, cytogenetic changes are important predictors of patient outcome. In this setting, the most important changes are deletion 17p, del(17p), and translocation of chromosomes 4 and 14, t(4;14), conferring a poor outcome. However, a certain degree of heterogeneity is observed in the survival of these high-risk patients. We hypothesized that other chromosomal changes may impact the outcome. We retrospectively analyzed a large series of 242 patients displaying either t(4;14) (157 patients) or del(17p) (110 patients), 25 patients presenting both abnormalities, using single nucleotide polymorphism array. In patients with t(4;14), del(1p32), del22q, and >30 chromosomal structural changes negatively impacted progression-free survival (PFS). For overall survival (OS), del(13q14), del(1p32), and the number of chromosomal structural changes worsened the prognosis of patients. For patients with del(17p), del6q worsened the prognosis of patients, whereas trisomy 15 and monosomy 14 were found to have a protective effect on PFS. For OS, del(1p32) worsened the prognosis of patients, whereas having >8 numerical changes was found to have a protective effect on survival. This study, which is the largest series of high-risk patients analyzed with the most modern genomic technique, identified 1 main factor negatively impacting survival: del(1p32).

We analyzed quantitative chromosome 14 abnormalities in 124 meningiomas by interphase fluorescence in situ hybridization (iFISH) and confirmed the nature of abnormalities by comparative genomic hybridization (CGH). We correlated the abnormalities with clinical, histopathologic, and prognostic factors. Of 124 cases, 50 (40.3%) showed loss (14.5%) or gain (25.8%) of the 14q32 chromosome region by iFISH. Most corresponded to numeric abnormalities: monosomy (12.9%), trisomy (1.6%), or tetrasomy (24.2%); in only 2 cases (1.6%), chromosome 14 loss did not involve the whole chromosome and was restricted to the 14q31-q32 region (confirmed by CGH). Cases with gain or monosomy corresponded more frequently to histologically malignant tumors (P = .009). Patients with monosomy 14/14q-, but not those with gain, more often were male (P = .04) and had a greater incidence of recurrence (P = .003) and shorter relapse-free survival (P = .03). The 2 patients with loss limited to 14q31-q32 had histologically benign tumors and no relapse after more than 5 years' follow-up. Most meningiomas with chromosome 14 abnormalities have numeric changes, with interstitial deletions of 14q31-q32 present in few cases. Of the abnormalities detected, only monosomy 14 showed an adverse prognostic impact.

A 1-year-old child with clinical features of monosomy 14 is reported. She has dysmorphic facial features including ocular colobomata, dolichocephaly and microcephaly, retinal pigmentation, severe seizures, fair curly hair and tapering fingers. There was severe mental retardation. This is the first reported case of severe mosaic monosomy 14, with up to 30% mosaicism. A recognizable facial gestalt is present in children with 14q deletions or partial monosomy 14, as well as susceptibility to infection, feeding difficulties, seizures and retinal pigmentation.

The diagnosis of gastrointestinal stromal tumor (GIST) is currently based on morphologic features and immunohistochemical demonstration of KIT (CD117). However, some tumors (in our estimation approximately 4%) have clinicopathologic features of GIST but do not express KIT. To determine if these lesions are truly GISTs, we evaluated 25 tumors with clinical and histologic features typical of GIST, but with negative KIT immunohistochemistry, for KIT and PDGFRA mutations using DNA extracted from paraffin-embedded tissue. Most tumors originated in the stomach (N = 14) or omentum/mesentery (N = 5). The neoplasms were composed of epithelioid cells (13 cases), admixed epithelioid and spindle cells (8 cases), or spindle cells (4 cases). Absence of KIT expression was confirmed by immunoblotting in 5 cases. Tumor karyotypes performed in 4 cases were noncomplex with monosomy 14 or 14q deletion, typical of GIST. Mutational analysis revealed PDGFRA and KIT mutations in 18 and 4 tumors, respectively, whereas 3 tumors did not have apparent KIT or PDGFRA mutations. The PDGFRA mutations primarily involved exon 18 (N = 15) and included 11 tumors with missense mutation in codon 842 (PDGFRA D842V or D842Y). In conclusion, a small subset of GISTs with otherwise typical clinicopathologic and cytogenetic features do not express detectable KIT protein. When compared with KIT-positive GISTs, these KIT-negative GISTs are more likely to have epithelioid cell morphology, contain PDGFRA oncogenic mutations, and arise in the omentum/peritoneal surface. Notably, some KIT-negative GISTs contain imatinib-sensitive KIT or PDGFRA mutations; therefore, patients with KIT-negative GISTs should not, a priori, be denied imatinib therapy.

Objective: Although information on the cytogenetic characteristics of meningioma tumors has accumulated progressively over the past few decades, information on the genetic heterogeneity of meningiomas is still scanty. The aim of the present study was to analyze by interphase fluorescence in situ hybridization (FISH) the incidence of numerical abnormalities for chromosomes 1, 9, 10, 11, 14, 15, 17, 22, X, and Y in a group of 70 consecutive meningioma tumors. Another goal was to establish the potential associations among the altered chromosomes, as a way to assess both intertumoral and intratumoral heterogeneity. Methods: For the purpose of the study, 70 patients diagnosed with meningioma were analyzed. Interphase FISH for the detection of numerical abnormalities for chromosomes 1, 9, 10, 11, 14, 15, 17, 22, X, and Y was applied to fresh tumor samples from each of the patients studied. Results: The overall incidence of numerical abnormalities was 76%. Chromosome Y in males and chromosome 22 in the whole series were the most common abnormalities (46% and 61%, respectively). Despite the finding that monosomy of chromosome 22/22q- deletions are the most frequent individual abnormality (53%), we have observed that chromosome gains are significantly more common than chromosome losses (60% versus 40%). Chromosome gains corresponded to abnormalities of chromosomes 1 (27%), 9 (25%), 10 (23%), 11 (22%), 14 (33%), 15 (22%), 17 (23%), and X in females (35%) and males (23%) whereas chromosome losses apart from chromosome 22 frequently involved chromosomes 14 (19%), X in males (23%), and Y in males (32%). Although an association was found among most gained chromosomes on one side and chromosome losses on the other side, different association patterns were observed. Furthermore, in the latter group, monosomy 22/22q- was associated with monosomy X in females and monosomy 14/14q- was associated with nulisomy Y in males. In addition, chromosome losses usually involved a large proportion of the tumor cells whereas chromosome gains were restricted to small tumor cell clones, including tetraploid cells. Conclusions: Our results show that meningiomas are genetically heterogeneous tumors that display different patterns of numerical chromosome changes, as assessed by interphase FISH. Cytometry (Clin. Cytometry) 50:153–159, 2002. © 2002 Wiley-Liss, Inc.

Aims Cytogenetic studies on renal cell carcinomas (RCCs) have disclosed a correlation between chromosome aberrations and histomorphological features. Nevertheless, it is still controversial whether the cytomorphology of the tumour cells (clear cell, chromophilic, chromophobe) or their growth pattern (nonpapillary, papillary) is more discriminative for the combined histomorphological–cytogenetic classification of RCCs. Methods and results Three RCCs with papillary growth pattern and clear cell cytomorphology were analysed by classical cytogenetics using standard G-banding techniques. Each tumour displayed clonal aberrations leading to loss of terminal 3p chromosomal segments. Monosomy 14 was also consistently found. Trisomy 17 was not observed in any of the tumours. Conclusions This series of three RCCs consisting of clear cells with papillary architecture revealed chromosomal aberrations characteristic for the conventional (clear cell) RCC. Irrespective of the predominant papillary growth pattern, none of the cases were characterized by trisomy of chromosomes 3q, 7, 8, 12, 16, 17 and 20 and loss of Y chromosome which are widely regarded as the most consistent genetic alterations for papillary RCC. Therefore, our cytogenetic findings provide evidence that papillary clear cell RCCs should be classified according to their cytomorphology rather than their growth pattern even when papillary architecture is prominent.

Monosomy of chromosome 14 has been reported in only a few prenatal cases. Generally, this monosomy is associated with a mosaicism of ring chromosome 14. Ring chromosome 14 is a rare cytogenetic entity with clinical characteristics that include growth retardation, facial dysmorphia, hypotonia, seizures, and retinitis pigmentosa. Given that the majority of symptoms appear postnatally, few cases have been reported of prenatal diagnosis of mosaicism monosomy/ring chromosome 14. We describe the prenatal diagnosis of a case of chromosomal mosaicism, a cell line with ring chromosome 14, r(14), and a second cell line with monosomy 14, in a fetus with aortic coarctation and chamber asymmetry. This is the first case of a prenatal diagnosis associating mosaicism with ring chromosome 14, monosomy 14, and fetal cardiopathy. We identified the exact breakpoint in ring chromosome 14 in IGH locus, which may provide further insight into the mode of ring formation as well as prenatal findings.

Purpose: Recurrence is the major factor influencing the clinical outcome of meningioma patients although the exact relationship between primary and recurrent tumors still needs to be clarified. The aim of the present study is to analyze the cytogenetic relationship between primary and subsequent recurrent meningiomas developed within the same individual. Experimental Design: Multicolor interphase fluorescence in situ hybridization was done for the identification of numerical abnormalities of 12 chromosomes in single-cell suspensions from 59 tumor samples corresponding to 25 recurrent meningioma patients. In 47 of these tumors, the distribution of different tumor cell clones was also analyzed in paraffin-embedded tissue sections. In parallel, 132 nonrecurrent cases were also studied. Results: Most recurrent meningiomas showed complex cytogenetic aberrations associated with two or more tumor cell clones in the first tumor analyzed. Interestingly, in most individuals (74%), exactly the same tumor cell clones identified in the initial lesion were also detected in the subsequent recurrent tumor samples. In the recurrent tumor samples of the remaining cases (26%), we observed tumor cell clones related to those detected in the initial lesion but which had acquired one or more additional chromosome aberrations associated with either the emergence of new clones with more complex karyotypes or the disappearance of the most representative clones from the primary lesions. Multivariate analysis of prognostic factors showed that the Maillo et al. prognostic score, based on age of patient, tumor grade, and monosomy 14, together with tumor size was the best combination of independent variables for predicting tumor recurrence at diagnosis. Conclusion: Overall, our results indicate that the development of recurrent meningiomas after complete tumor resection is usually due to regrowth of the primary tumor and rarely to the emergence of an unrelated meningioma, underlining the need for alternative treatment strategies in cases at high risk of relapse, particularly those with a high Maillo et al. prognostic score and larger tumors.

We performed cytogenetic analyses of 8 renal oncocytomas to identify chromosomal regions involved in the tumorigenesis of oncocytomas. All cases showed chromosomal findings corresponding to established cytogenetic subsets of renal oncocytomas: 3 cases with normal karyotypes, 1 case with rearrangement of 11q, and 4 cases with losses of chromosome 14. In the latter cytogenetic subgroup, monosomy 14 was additionally accompanied by either monosomy 1 in 2 cases or loss of 1p in a third case, providing insights in the cytogenetic evolution of this subgroup.

In this study cytogenetic findings have been correlated with prognosis in 78 previously untreated patients with non-Hodgkin's lymphoma (NHL) presenting between 1983 and 1988. The median follow-up was 7 years (range 2-9 years). There was no significant difference in the duration of survival of 33 patients with only abnormal karyotypes, 35 patients with a mixture of normal and abnormal karyotypes (AN) and 10 patients with only normal karyotypes (NN). This was true for the entire group (p = 0.6) as well as for the subsets of diffuse lymphomas (DL) and follicular lymphomas (FL) (p = 0.6 and 0.4, respectively). Monosomy 14 was the only abnormality in the entire group of patients to be associated with a statistically significant difference in survival duration (p = 0.046). Among the FL patients, trisomy 7 (p = 0.046) and trisomy 12 (p = 0.010) were associated with shorter survival. Presence of t(14;18) did not influence survival in the entire group (p = 0.16), nor in any of the histological subgroups. Among the FL patients with t(14;18), presence of additional cytogenetic abnormalities was not associated with a worse outcome. The lack of consistency of results between various studies is likely to be due to several factors and the prognostic significance of karyotypic abnormalities can only be clarified by large prospective studies employing uniform treatment policies.

The chromosomes of a human gastric leiomyosarcoma were studied in preparations from short-term cultures. The tumor had a triploid-near-triploid modal population characterized by extensive numerical and structural changes. Of these deviations, del(1)(p12–13), monosomy 14, and underrepresentation of chromosomes 18 and 22 were abnormalities in common with two of the three previously studied leiomyosarcomas of the small bowel.

A young woman, with ataxia telangiectasia (AT) had a chromosomally abnormal T-lymphocyte clone detected at 23 years of age. This clone showed nonrandom loss of chromosome #14, a karyotypic abnormality not previously described in AT. Eighteen months later, evolution of the monosomic clone was noted; the karyotype of this latter clone was 45,XX,−14,del(6) (q21). The patient died of Hodgkin's disease of mixed cellularity type, Stage IIIB, a few months later. A striking histological feature of a lymph node biopsy was the presence of numerous epithelioid histiocytes. The patient's paternal first cousin also suffers from AT.

We describe a German family carrying a constitutional translocation (3;6) (p13;q25.1) in 3 consecutive generations. The only member of the family over 50 years of age and carrying the translocation developed multiple bilateral renal-cell carcinomas. We performed chromosome analysis of 4 out of 5 primary tumours, which were characterized by different clonal karyotypes. The constitutionally translocated 3p13-pter segment was lost with or without the receptor chromosome 6 in each tumour. Additional karyotypic changes were trisomy 5, 7 and 18, monosomy 14 and 21, and loss of the Y chromosome, all karyotype changes occurring frequently in sporadic non-papillary RCCs. This case is discussed with regard to the possible role of suppressor gene inactivation by constitutional translocation in the development of familial renal cancers.

A 12-year-old boy with congenital heart disease, short stature, mildly dysmorphic facies, and mild intellectual impairment was found to have a de novo terminal deletion (14)(q32.3). Although his phenotype resembles that of six reported patients with a similar breakpoint, his CNS involvement is milder. He appears to be the first reported case of a terminal deletion of chromosome 14 not associated with ring 14 formation. Advanced parental ages and maternal origin of the chromosome with the deletion are noted.

Cytogenetic studies on 31 human meningiomas revealed clonal abnormalities in 14 of them. Monosomy 22 was present in three cases as the only abnormality, and in five it was associated with monosomy 18, monosomy 14, loss of X, loss of Y, and trisomy 20, respectively. We found a number of rearrangements involving chromosome #22: an i psu dic(22)(pter----q11::q11----pter) in two cases and a t(18;22)(q12;q11) in another case. Two cases showed a complex translocation involving #7 and #14: t(2;7;14)(q23;q36;q22) and t(1;7;14)(q25;q32;q22), respectively. Other clonal chromosome abnormalities were del(1p) (present in two cases); der(9)t(9;?)(q34;?); der(7)t(7;?)(q31;?); der(22)t(22;?)(q11;?); and a 9p+ chromosome. The relevance for the pathogenesis of human meningiomas of these chromosome anomalies is also discussed with reference to the previous literature. The possible involvement of recessive cancer genes present on the long arm of chromosome #22 is also discussed.