High-resolution epitope mapping and characterization of SARS-CoV-2 antibodies in large cohorts of subjects with COVID-19

As Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) continues to spread, characterization of its antibody epitopes, emerging strains, related coronaviruses, and even the human proteome in naturally infected patients can guide the development of effective vaccines and therapies. Since traditional epitope identification tools are dependent upon pre-defined peptide sequences, they are not readily adaptable to diverse viral proteomes. The Serum Epitope Repertoire Analysis (SERA) platform leverages a high diversity random bacterial display library to identify proteome-independent epitope binding specificities which are then analyzed in the context of organisms of interest. When evaluating immune response in the context of SARS-CoV-2, we identify dominant epitope regions and motifs which demonstrate potential to classify mild from severe disease and relate to neutralization activity. We highlight SARS-CoV-2 epitopes that are cross-reactive with other coronaviruses and demonstrate decreased epitope signal for mutant SARS-CoV-2 strains. Collectively, the evolution of SARS-CoV-2 mutants towards reduced antibody response highlight the importance of data-driven development of the vaccines and therapies to treat COVID-19.

Using a high throughput, random bacterial peptide display approach applied to patient serum samples, Haynes, Kamath, Bozekowski et al identify the antigens and epitopes that elicit a SARS-CoV-2 humoral response. They identify differences depending on disease severity and further in silico analysis suggests decreased epitope signal for Q677P but not for D614G mutant SARSCoV-2 strains.

Serum and Cervicovaginal Fluid Antibody Profiling in Herpes Simplex Virus (HSV) Seronegative Recipients of the HSV529 Vaccine

Previous HSV2 vaccines have not prevented genital herpes. Concerns have been raised about the choice of antigen, the type of antibody induced by the vaccine, and whether antibody is present in the genital tract where infection occurs. We reported results of a trial of an HSV2 replication-defective vaccine, HSV529, that induced serum neutralizing antibody responses in 78% of HSV1 -/HSV2 - vaccine recipients. Here we show that HSV1 -/HSV2 - vaccine recipients developed antibodies to epitopes of several viral proteins; however, fewer antibody epitopes were detected in vaccine recipients compared with naturally infected persons. HSV529 induced antibodies that mediated HSV2-specific NK cell activation. Depletion of gD-binding antibody from sera reduced neutralizing titers by 62% and NK cell activation by 81%. HSV2 gD antibody was detected in cervicovaginal fluid at about one-third the level of that in serum. A vaccine that induces potent serum antibodies transported to the genital tract might reduce HSV genital infection.

Serum Epitope Repertoire Analysis Enables Early Detection of Lyme Disease with Improved Sensitivity in an Expandable Multiplex Format

Widely employed diagnostic antibody serology for Lyme disease, known as standard two-tier testing (STTT), exhibits insufficient sensitivity in early Lyme disease, yielding many thousands of false-negative test results each year. Given this problem, we applied serum antibody repertoire analysis (SERA), or next-generation sequencing (NGS)-based serology, to discover IgG and IgM antibody epitope motifs capable of detecting Lyme disease-specific antibodies with high sensitivity and specificity. Iterative motif discovery and bioinformatic analysis of epitope repertoires from subjects with Lyme disease (n = 264) and controls (n = 391) yielded a set of 28 epitope motifs representing 20 distinct IgG antibody epitopes and a set of 38 epitope motifs representing 21 distinct IgM epitopes, which performed equivalently in a large validation cohort of STTT-positive samples. In a second validation set from subjects with clinically defined early Lyme disease (n = 119) and controls (n = 257), the SERA Lyme IgG and IgM assay exhibited significantly improved sensitivity relative to STTT (77% versus 62%; Z-test; P = 0.013) and improved specificity (99% versus 97%). Early Lyme disease subjects exhibited significantly fewer reactive epitopes (Mann-Whitney U test; P < 0.0001) relative to subjects with Lyme arthritis. Thus, SERA Lyme IgG and M panels provided increased accuracy in early Lyme disease in a readily expandable multiplex assay format.

Influence of endogenous angiotensin II on control of sympathetic nerve activity in human dehydration

Arterial blood pressure can often fall too low during dehydration, leading to an increased incidence of orthostatic hypotension and syncope. Systemic sympathoexcitation and increases in volume regulatory hormones such as angiotensin II (AngII) may help to maintain arterial pressure in the face of decreased plasma volume. Our goals in the present study were to quantify muscle sympathetic nerve activity (MSNA) during dehydration (DEH), and to test the hypothesis that endogenous increases in AngII in DEH have a mechanistic role in DEH-associated sympathoexcitation. We studied 17 subjects on two separate study days: DEH induced by 24 h fluid restriction and a euhydrated (EUH) control day. MSNA was measured by microneurography at the peroneal nerve, and arterial blood pressure, electrocardiogram, and central venous pressure were also recorded continuously. Sequential nitroprusside and phenylephrine (modified Oxford test) were used to evaluate baroreflex control of MSNA. Losartan (angiotensin type 1 receptor (AT1) antagonist) was then administered and measurements were repeated. MSNA was elevated during DEH (42 +/- 5 vs. EUH: 32 +/- 4 bursts per 100 heartbeats, P = 0.02). Blockade of AT1 receptors partially reversed this change in MSNA during DEH while having no effect in the control EUH condition. The sensitivity of baroreflex control of MSNA was unchanged during DEH compared to EUH. We conclude that endogenous increases in AngII during DEH contribute to DEH-associated sympathoexcitation.

Mitochondrial DNA determines androgen dependence in prostate cancer cell lines

Prostate cancer progresses from an androgen-dependent to androgen-independent stage after androgen ablation therapy. Mitochondrial DNA plays a role in cell death and metastatic competence. Further, heteroplasmic large-deletion mitochondrial DNA is very common in prostate cancer. To investigate the role of mitochondrial DNA in androgen dependence of prostate cancers, we tested the changes of normal and deleted mitochondrial DNA in accordance with the progression of prostate cancer. We demonstrated that the androgen-independent cell line C4-2, established by inoculation of the androgen-dependent LNCaP cell line into castrated mice, has a greatly reduced amount of normal mitochondrial DNA and an accumulation of large-deletion DNA. Strikingly, the depletion of mitochondrial DNA from androgen-dependent LNCaP resulted in a loss of androgen dependence. Reconstitution of normal mitochondrial DNA to the mitochondrial DNA-depleted clone restored androgen dependence. These results indicate that mitochondrial DNA determines androgen dependence of prostate cancer cell lines. Further, mitochondrial DNA-deficient cells formed tumors in castrated athymic mice, whereas LNCaP did not. The accumulation of large deletion and depletion of mitochondrial DNA may thus play a role in the development of androgen independence, leading to progression of prostate cancers.

Soft tissue masses in patients with multiple myeloma: a fine-needle aspiration study of 30 cases with flow cytometry and clinical correlation

BACKGROUND

To the authors' knowledge, the prognostic significance of plasma cell cytology in soft tissue (ST) masses from patients with multiple myeloma (MM) is unknown. Myeloma patients usually are monitored by bone marrow (BM) aspirates and biopsies to assess plasma cell differentiation, tumor burden, and response to treatment. Monitoring of ST lesions by fine-needle aspiration (FNA) is not performed routinely. The objective of the current study was to examine ST masses in MM patients using FNA and to classify and determine the prognostic significance of MM in these lesions based on cytologic features.

METHODS

FNAs of 30 ST masses from 27 patients with a history of MM were examined for disease involvement. In the patients with MM, the cytologic features were evaluated and the lesions were graded as low grade, intermediate grade, or high grade based on the classification of Bartl et al. for MM in BM specimens. Concurrent BM samples as well as cytogenetic and flow cytometric results also were reviewed.

RESULTS

Twenty-seven of the FNA specimens (90%) were positive for MM, and three specimens (10%) were negative (one case each of lipoma, keratinous cyst, and aspergillosis). Among the MM cases, 5 (18.5%) were low grade, 15 (55.6%) were intermediate grade, and 7 (25.9%) were high grade (blastic MM). Simultaneous BM involvement was present in 23.5% of low-grade MM (4 of 17 cases), 35.3% of intermediate-grade MM (6 of 17 cases), and 71% of high-grade MM (5 of 7 cases). Clinically, 10 of 24 patients (42%) died within 9 months (median, 2 months). Patients with high-grade myeloma (blastic MM) in ST masses appeared to have worse survival; 43% (3 of 7 patients) died by a median time of 2 months, compared with 12% of patients with low-grade and intermediate-grade MM (2 of 17 patients).

CONCLUSIONS

FNA of ST masses appears to improve the management of MM patients by providing diagnostic material, samples for ancillary studies, and prognostic information. ST MM can be classified reliably into grades of prognostic significance utilizing the classification of Bartl et al. Intermediate-grade MM was the most frequent subtype present in ST masses.

Identification of isochromosome 1q as a recurring chromosome aberration in skull base chordomas: a new marker for aggressive tumors?

Object

The authors conducted a study of 22 skull base chordomas.

Methods

A series of 22 skull base chordomas was analyzed with G banding. Subsequently, metaphase cells obtained from three tumors were reexamined using multicolor spectral karyotyping. Clonal chromosome aberrations were identified in 11 cases, all of which were recurrent tumors. Three tumors showed a remarkable similarity in cytogenetic features, and these features appear to characterize a recurring combination of nonrandom chromosome aberrations, including isochromosome 1q, gain of chromosome 7, and monosomy for chromosomes 3, 4, 10,13, and 18. Isochromosome 1q was identified as the sole recurring structural chromosome rearrangement in these tumors. The pattern of chromosome loss reported in the progression of lumbosacral chordoma also appears to be true of skull base chordomas with the additional findings of isochromosome 1q, gain of chromosome 7, and loss of chromosome 18.

Conclusions

Skull base chordomas characterized by isochromosome 1q and monosomy 13 provide support for the concept of the loss of putative tumor suppressor loci on 1p and 13q and aggressive tumor behavior.

Cyclin D1 and E2F-1 immunoreactivity in bone marrow biopsy specimens of multiple myeloma: relationship to proliferative activity, cytogenetic abnormalities and DNA ploidy

Cyclin D1, encoded by the CCND1 gene, is immunohistochemically detectable in up to one-third of cases of multiple myeloma (MM). To examine the mechanism of cyclin D1 overexpression, we compared cyclin D1 immunoreactivity with the results of conventional cytogenetics to determine if the t(11;14)(q13;q32) or other abnormalities of 11q11-14 explained cyclin D1 overexpression. Karyotypic abnormalities were found in 45 out of 67 (67%) MM cases; the t(11;14) was present in seven cases (10%). Additional 11q11-14 abnormalities were not identified. The t(11;14) correlated with cyclin D1 upregulation in low to intermediately proliferative MM, but was not present in highly proliferative tumours (assessed using bromodeoxyuridine labelling index). Cyclin D1 indirectly activates the transcription factor E2F-1. In the bone marrow biopsy specimens of MM cases, E2F-1 was concurrently expressed with cyclin D1 (P = 0.001), indicating that cyclin D1 is functional. However, as neither E2F-1 nor cyclin D1 expression correlated with proliferative activity, the speculation that t(11;14) upregulates the CCND1 gene to induce higher proliferation and possibly more aggressive disease is not supported. We conclude that in low to intermediately proliferative MM cases, cyclin D1 is probably upregulated by t(11;14), but an alternative mechanism is more probable in highly proliferative MM.

A novel reciprocal (10;17)(p11.2;q23) in myxoid fibrosarcoma

Recurring reciprocal translocations have been identified as the primary chromosome aberrations in a number of neoplasms. These aberrations are often closely associated with particular morphologic or phenotypic subtypes of tumors and in some cases have prognostic implications. We have identified a novel reciprocal t(10;17)(p11.2;q23) in a case of low-grade myxoid fibrosarcoma, which may prove to be a new tumor specific chromosome aberration.

Multicolour spectral karyotyping identifies new translocations and a recurring pathway for chromosome loss in multiple myeloma

Multicolour spectral karyotyping (SKY) was performed on primary tumour specimens from 100 patients with multiple myeloma (MM) that showed complex clonal chromosome aberrations not fully characterized by G-banding. In this study, SKY was able to identify or revise translocations with breakpoints involving 14q32, 11q13 or 8q24 in 32 patients (32%). Five new recurring translocations were identified, two of which involved chromosome 22. A subtle reciprocal translocation t(14;22) (q32;q11 approximately 12) was identified using SKY in two patients and a second, much larger, translocation t(11;22)(q13;q13) was identified using G-banding in three patients. A third new translocation was identified in two patients using SKY and G-banding as der(7)t(7;7)(p15 approximately 22;q22 approximately 32). Twenty-three patients (23%) showed the loss of 8p by whole-arm translocations with different whole-arm donor chromosomes. Among this group, two new recurring whole-arm translocations involving the centromeric breakpoint 8q10 were identified as der(8;20)(q10;q10) and der(8;18) (q10;q10) in three patients each. In addition, a novel pattern of three-way translocations involving the clonal evolution of the t(8;22)(q24;q11) by the subsequent loss of 8p by whole-arm translocations was found in three patients. The chromosome instability identified here demonstrates that the loss of 8p can occur by multiple whole-arm translocations, indicating a new pathway for the loss of a specific chromosome region in MM.

Evi27 encodes a novel membrane protein with homology to the IL17 receptor

Evi27 is a common site of retroviral integration in BXH2 murine myeloid leukemias. Here we show that integration at Evi27 occurs in a CpG island approximately 6 kb upstream from a novel gene (designated Evii27) with homology to the IL17 receptor (Il17r) and that proviral integrations result in increased expression of the Evi27 protein on the cell surface. The human EVI27 homolog was also cloned and mapped to chromosome 3p21. Multiple Evi27 isoforms were detected at the RNA and protein level in both human and mouse, indicating that Evi27 expression is complex. Some of the isoforms are shown to likely represent secreted soluble forms of the protein produced by intron incorporation or by proteolytic cleavage. In the mouse, highest Evi27 expression occurs in liver and testes with lower expression in kidney and lung. In humans, EVI27 is expressed at high levels in the kidney, with moderate levels in the liver, brain, and testes. Within hematopoietic cells, Evi27 expression is restricted. Northern and Western analysis showed that Evi27 is expressed in selected T-cell, B-cell and myeloid cell lines. These results suggest that Evi27 expression is tightly regulated during hematopoietic differentiation. Collectively, these studies identify a new member of the cytokine receptor family whose increased and uncoordinated expression may lead to myeloid leukemia by altering Evi27's normal ability to control the growth and/or differentiation of hematopoietic cells.

Fracture patterns in children and young adults who fall from significant heights

Trauma is a leading cause of morbidity and mortality for children and young adults. When all causes of trauma are considered, falls are the most common mechanism of injury. To address specifically age-related fracture patterns in children who fall, we identified 125 consecutive patients, 21 years old or younger, who fell from a height of 10 feet or greater. The medical records and radiographs for 110 of these patients were available for review. Patients were divided into three groups based on age: there were 25 infant/toddlers (0-2 years), 55 children (3-10 years), and 30 adolescent/young adults (11-21 years). We found statistically significant differences in fracture distribution between the groups. The adolescent/young adult group sustained a greater number of vertebral fractures (p<0.003) and total fractures per fall (p<0.015). The children, in contrast, had a greater number of long bone fractures (p<0.05). Knowledge of age-related fracture patterns could result in improved diagnosis and treatment of these injuries.

A role for telomeric and centromeric instability in the progression of chromosome aberrations in meningioma patients

BACKGROUND

The primary chromosome aberration in meningiomas is monosomy or deletion of chromosome 22. Common secondary aberrations include losses or deletions of chromosomes 1p, 14q, and 10q and unstable chromosome aberrations including rings, dicentrics, and telomeric associations. Despite the analysis of several hundred tumors by cytogenetic and molecular techniques, the mechanisms involved in the progression of chromosome aberrations in meningioma remain poorly understood.

METHODS

Sixty-seven meningiomas were cultured successfully using a short term in situ technique and harvested incorporating a high resolution G-banding technique with ethidium bromide.

RESULTS

Twenty-six tumors (39%) showed normal karyotypes, whereas 41 tumors (61%) showed clonal chromosome aberrations. The most frequently observed aberration was the loss of chromosome 22 or structural aberrations involving 22q12, which occurred in 30 tumors (45%). The second most common aberrations were whole arm translocations involving the centromeric breakpoint at 1q10, resulting in the loss of the entire 1p chromosome in 12 tumors (18%). Two tumors showed a new, recurring, unbalanced, whole arm translocation der(1;2)(q10;q10). A third aberration, telomeric associations, were observed in 16 tumors (24%), occurring transiently in 11 tumors and recurring clonally in 5 tumors. Dicentric chromosome 22 was found in 7 tumors (10%), with the progressive loss of chromosome 22q material being found in 2 tumors.

CONCLUSIONS

The chromosome instability demonstrated in the current series of tumors suggests that the progression of chromosome aberrations in meningioma is mediated in some respects by both telomeric and centromeric instability. These two types of instability may be early events in the progression of chromosome aberrations in meningioma and each can account for at least some of the loss of heterozygosity of chromosomes 22q and 1p detected by molecular analysis.

Identification of new nonrandom translocations in multiple myeloma with multicolor spectral karyotyping

Multicolor spectral karyotyping (SKY) was performed on bone marrow samples from 50 patients with multiple myeloma (MM) in anticipation of discovering new previously unidentified translocations. All samples showed complex karyotypes with chromosome aberrations which, in most cases, were not fully characterized by G-banding. Patients of special interest were those who showed add(14)(q32), add(8)(q24) and those whose G-banding karyotypes showed poor chromosome morphology. Three new recurring chromosome translocations not previously reported in MM were identified. Two of the translocations involve recurring aberrations at band 14q32.3, the site of the IgH locus, with different exchange partners. The most frequently recurring rearrangement was a subtle translocation at 14q32.3 designated as a t(14;16)(q32;q22 approximately 23), which was identified in six patients. A second and larger translocation at 14q32, identified in two patients, was designated as a t(9;14)(p13;q32), previously associated with Waldenstrom's macroglobulinemia and lymphoplasmacytoid lymphoma. A third translocation, identified in two patients, involved a whole-arm t(6;8)(p10;q10) translocation. The SKY technique was able to refine the designations of over 156 aberrations not fully characterized by G-banding in this study and resolved additional chromosome aberrations in every patient studied except two. The t(14;16)(q32;q22 approximately 23) identified by SKY in this study suggests this may be a frequent translocation in MM associated with complex karyotypes and disease progression. Therefore, the SKY technique provides a useful adjunct to routine G-banding and fluorescence in situ hybridization studies in the cytogenetic analysis of MM.

Jumping translocations of chromosome 1q in multiple myeloma: evidence for a mechanism involving decondensation of pericentromeric heterochromatin

Karyotypes in multiple myeloma (MM) are complex and exhibit numerous structural and numerical aberrations. The largest subset of structural chromosome anomalies in clinical specimens and cell lines involves aberrations of chromosome 1. Unbalanced translocations and duplications involving all or part of the whole long arm of chromosome 1 presumably occur as secondary aberrations and are associated with tumor progression and advanced disease. Unfortunately, cytogenetic evidence is scarce as to how these unstable whole-arm rearrangements may take place. We report nonrandom, unbalanced whole-arm translocations of 1q in the cytogenetic evolution of patients with aggressive MM. Whole-arm or "jumping translocations" of 1q were found in 36 of 158 successive patients with abnormal karyotypes. Recurring whole-arm translocations of 1q involved chromosomes 5,8,12,14,15,16,17,19,21, and 22. A newly delineated breakpoint present in three patients involved a whole-arm translocation of 1q to band 5q15. Three recurrent translocations of 1q10 to the short arms of different acrocentric chromosomes have also been identified, including three patients with der(15)t(1;15)(q10;p10) and two patients each with der(21)t(1;21)(q10;p13) and der(22)t(1;22) (q10;p10). Whole-arm translocations of 1q10 to telomeric regions of nonacrocentric chromosomes included der(12)t(1;12) (q10;q24.3) and der(19)t(1;19)(q10;q13.4) in three and two patients, respectively. Recurrent whole-arm translocations of 1q to centromeric regions included der(16)t(1;16)(q10;q10) and der(19)t(1;19)(q10;p10). The mechanisms involved in the 1q instability in MM may be associated with highly decondensed pericentromeric heterochromatin, which may permit recombination and formation of unstable translocations of chromosome 1q. The clonal evolution of cells with extra copies of 1q suggests that this aberration directly or indirectly provides a proliferative advantage.

A new reciprocal translocation (12;22)(q24.3;q11.2-12) in a malignant rhabdoid tumor of the brain

We report a malignant rhabdoid tumor (MRT) of the brain with a novel reciprocal translocation, t(12;22)(q24.3;q11.2-12). Previous reports of chromosome abnormalities in MRTs were characterized either by monosomy or partial deletions of chromosome 22. An unbalanced translocation has been identified in only a single case. To our knowledge, the present report is the first to describe a balanced reciprocal translocation in an MRT of the brain. The identification of this subtle translocation further sublocalizes the chromosomal breakpoint on chromosome 22, and could be of potential diagnostic value in cerebral MRTs.

Evidence of an association between 6q13-21 chromosome aberrations and locally aggressive behavior in patients with cartilage tumors

BACKGROUND

The finding of a cytogenetic-pathologic correlation between complex karyotypes and high grade cartilaginous tumors has been reported. However, few cytogenetic reports exist regarding benign or low grade lesions. A subset of low grade malignant cartilaginous tumors is characterized by locally aggressive behavior but no metastatic potential. Because the histopathologic distinction between benign, borderline, or low grade malignant cartilaginous lesions can be difficult, the finding of additional tumor markers associated with the clinical behavior of borderline cartilaginous lesions could be clinically significant.

METHODS

Four cartilaginous tumors, including an osteochondroma (OC), a chondromyxoid fibroma (CF), an enchondroma (EC), and a dedifferentiated chondrosarcoma (DCS), were cultured and harvested using short term, in situ culture techniques. Chromosome analysis was performed by conventional G-banding and fluorescence in situ hybridization was used to confirm G-banding.

RESULTS

The stemlines of all four tumors showed multiple chromosome anomalies that included aberrations of 6q13-21. The OC showed a t(6;16)(q21;p13.3). The CF showed a complex rearrangement between the chromosome 6 homologues, resulting in an inv(6)(p25q23)t(6;6)(q23;q13). This tumor also showed the clonal evolution of telomeric associations resulting in duplications, deletions, and the formation of a ring 15. The EC showed a der(6)t(6;15)(q13;q11)t(15;22)(q22;q13) stemline and subclones with an unstable iso 17q that subsequently fused to both ends of chromosome 16. The DCS showed a del(6)(q13), r(9), +12 stemline.

CONCLUSIONS

The cytogenetic findings of this study suggest the cytogenetic-pathologic correlation of complex karyotypes found in high grade cartilage tumors may extend to lower grade tumors with complex karyotypes. These findings further suggest that chromosome aberrations in the region of 6q13-21 may be associated with locally aggressive behavior in patients with cartilage tumors.

Clonal telomeric fusions and chromosome instability in a subcutaneous sacrococcygeal myxopapillary ependymoma

Subcutaneous sacrococcygeal myxopapillary ependymoma (SSME) is a very rare neurologic tumor with no demonstrable connection to the spinal column. Little is known of its etiology, clinical characteristics, or cytogenetics. Giemsa-band analysis revealed a stemline karyotype showing 62 chromosomes. Sidelines within the tumor showed clonal telomeric fusions resulting in dicentric chromosomes involving the fusion of numerous chromosomes. Recurrent telomeric fusions resulted in the progressive deletion of chromosome bands 11q25 and 11q23 and subsequently the entire long arm. This is the first case of a SSME to show clonal cytogenetic aberrations. However, of greater interest is the demonstration of the clonal progression of telomeric fusions resulting in dicentric chromosomes and the subsequent loss of chromosome arms. The observation of clonal telomeric breakage/fusion cycles as progenitor lesions to subsequent deletions provides evidence for telomeric association as an intermediate step in the progression of chromosomal instability.

Mechanism for superior subluxation of the glenohumeral joint in fibrodysplasia ossificans progressiva

Progressive heterotopic ossification leads to ankylosis of the major joints in patients who have fibrodysplasia ossificans progressiva. Joint subluxation has not been recognized widely in patients with this disease. The clinical records and radiographs of 79 patients with fibrodysplasia ossificans progressiva were reviewed and, it was found that humeral to chest wall synostosis and subluxation of the glenohumeral joint had occurred in 21% of skeletally immature patients and in 74% of skeletally mature patients. In fibrodysplasia ossificans progressiva, synostosis of the humeral shaft to the chest wall commonly occurs by 7 years of age, well before the age of proximal physeal closure. The continued growth of the proximal humeral physis in the presence of a humeral to chest wall synostosis causes the humeral head to migrate superiorly, thus promoting growth related subluxation. The clinical significance of this finding for patients who have fibrodysplasia ossificans progressiva is unknown, but this unique model will be useful in the study of shoulder biomechanics and growth plate physiology.

Unique role of cytogenetics in the prognosis of patients with myeloma receiving high-dose therapy and autotransplants

PURPOSE

Although important predictors of survival in myeloma patients have been identified, it is well recognized that better prognostic factors for this disease are needed. Because cytogenetics play a dominant role in the outcome of patients with acute leukemia, their prognostic value was evaluated in a large group of newly diagnosed and previously treated myeloma patients receiving autotransplants.

METHODS

A total of 427 either newly diagnosed (26%) or previously treated patients (74%) received tandem transplants, supported by mobilized peripheral-blood stem cells. Numerous variables, including cytogenetics, were analyzed for their impact on complete remission, event-free survival (EFS), and overall survival (OS).

RESULTS

Abnormal karyotypes were detected in 37% of our patients and were very complex, irrespective of the duration of standard therapy before the first autotransplant. In addition to previously recognized unfavorable implications of partial or complete deletion of chromosome 13 and 11q abnormalities, we now observed that the presence of any translocation likewise portended poor outcome (unfavorable karyotypes). On multivariate analysis, the absence of an unfavorable karyotype was the most favorable variable for both EFS (P = .0001) and OS (P = .0001). Other favorable factors were duration of standard therapy and a low beta-2 microglobulin (B2M) level before the first autotransplant. A risk-based classification system was developed according to the number of these favorable variables present, showing highly significant differences in event-free and overall survival.

CONCLUSION

Cytogenetics play a dominant role in myeloma and were independent of previously recognized important prognostic factors, such as B2M and duration of prior standard therapy.

Telomeric fusion and chromosome instability in multiple tissues of a patient with mosaic Ullrich-Turner syndrome

We describe the cytogenetic evolution of multiple cell lines in the gonadal tissue of a 10-year-old girl with mosaic Ullrich-Turner syndrome (UTS) involving clonal telomeric associations (tas) of the Y chromosome. G-band analysis of all tissues showed at least 2 cell lines; 45, X and 46,X,tas(Y;21)(q12;p13). However, analysis of left gonadal tissue of this patient showed the evolution of 2 additional cell lines, one designated 45,X,tas(Y;21)(q12;p13),-22 and the other 46,X,tas(Y;21)(q12;p13),+tas(Y;14)(q12;p13), -22. Fluorescence in situ hybridization (FISH) analysis of interphase nuclei from uncultured gonadal tissue confirmed the findings of aneuploidy in the left gonadal tissue and extended the findings of aneuploidy to the tissue of the right gonad. The chromosome findings in the gonadal tissue of this patient suggest a preneoplastic karyotype relating to several distinct tumor associations. The clonal evolution of telomeric fusions indicates chromosomes instability and suggests the extra copy of the Y chromosome may have resulted from a fusion-related malsegregation. In addition, the extra Y suggests low-level amplification of a putative gonadoblastoma gene, while the loss of chromosome 22 suggests the loss of heterozygosity for genes on chromosome 22. This case demonstrates the utility of the study of gonadal tissue in 45,X/46XY UTS patients, and provides evidence that clonal telomeric fusions may, in rare cases, be associated with chromosome malsegregation and with the subsequent evolution of unstable karyotypes.

Secondary acute myelogenous leukemia following safe exposure to etoposide

PURPOSE

To present two patients as illustrations of the risk of developing secondary acute myelogenous leukemia (sAML) when theoretically safe doses of etoposide (VP-16) are used.

PATIENTS AND METHODS

Patient no. 1 was a 15-year-old white girl diagnosed with stage IIa Hodgkin's disease. She was treated with a combination of vincristine, doxorubicin, bleomycin, and VP-16 (2 g/m2 total) over 4 months, followed by 25.5 Gy of involved-field radiotherapy. Patient no. 2 was an 11-year-old white boy diagnosed with virus-associated hemophagocytic syndrome (VAHS). He was treated with VP-16 intravenously (IV) and orally (0.3 g and 2.8 g/m2, respectively).

RESULTS

Patient no. 1 developed AML 16 months from the diagnosis of Hodgkin's disease. Patient no. 2 developed AML 26 months from diagnosis. Both bone marrows were consistent with French-American-British (FAB) M4 disease. Both patients had abnormalities of the long arm of chromosome 11.

CONCLUSION

The use of low-dose or oral VP-16 can be associated with the development of sAML. Clinicians should be cautious in the use of VP-16 in low-risk diseases.

Sub-band deletion of 7q36.3 in a patient with ring chromosome 7: association with holoprosencephaly

We report on a patient with ring chromosome 7 analyzed by both high-resolution mid-prophase G-banding and fluorescence in situ hybridization (FISH) resolving a subband deletion of 7q36.3 associated with the clinical manifestation of holoprosencephaly (HPE).

Telomeric associations in the progression of chromosome aberrations in pediatric solid tumors

Telomeric association (tas) is a cytogenetic phenomenon in which chromosome ends fuse to form dicentric, multicentric, and ring chromosomes. We observed clonal tas in six pediatric solid tumors of various types and histological grades studied using short-term in situ culture and G-banding techniques. These tumors included a neurilemoma, an undifferentiated (embryonal) sarcoma of the liver (UESL), two anaplastic astrocytomas (AA), one case of glioblastoma multiforme (GBM), and a neuroblastoma (NB) of the kidney. Cytogenetic data from all six tumors demonstrated multiple numerical and structural aberrations including tas. The tas appeared to be a secondary aberration in these tumors, however, it was possible to follow the progression of the telomeric chromosome aberrations in several cases. In all but one case (UESL) the loss of chromosome segments occurred. Tas of 11p was observed in three of the six tumors, two of which showed the subsequent loss of 11p (AA and AB). In addition, tas of 4p was seen in three tumors, two of which showed clonal tas of 4p with 22q. Tas of 10p, 21p, and 22q were all observed in at least two different tumors. The clonal telomeric fusions of 4p with 22q, recurring tas of 11p, and the subsequent loss of the short arm of 11 demonstrated here, suggests that some chromosome regions are subject to nonrandom instability and sometimes loss.

A novel reciprocal translocation (14;15)(q11;q24) in a congenital mesoblastic nephroma

We describe a novel reciprocal translocation, t(14;15)(q11;q24), as the sole cytogenetic aberration in a congenital mesoblastic nephroma. The tumor was predominantly of "classic" morphology, but with small cellular islands of larger cells indicating early transformation to the cellular type. This is the first report of a reciprocal translocation as the sole anomaly in a congenital mesoblastic nephroma.

Molecular characterization of breakpoints in patients with holoprosencephaly and definition of the HPE2 critical region 2p21

Holoprosencephaly (HPE) is a common developmental defect involving the brain and face in humans. Cytogenetic deletions in patients with HPE have localized one of the HPE genes (HPE2) to the chromosomal region 2p21. Here we report the molecular genetic characterization of nine HPE patients with cytogenetic deletions or translocations involving 2p21. We have determined the parental origin of the deleted chromosomes and defined the HPE2 critical region between D2S119 and D2S88/D2S391. As a first step towards cloning the HPE2 gene which is crucial for normal brain development we have constructed a YAC contig which spans the smallest region of deletion overlap. Several of these YACs could be identified which span three different 2p21 breakpoints in HPE patients. These YACs narrow the HPE2 critical region to less than 1 Mb and are now being further analyzed to identify the gene causing holoprosencephaly on chromosome 2.

Poor prognosis in multiple myeloma is associated only with partial or complete deletions of chromosome 13 or abnormalities involving 11q and not with other karyotype abnormalities

Chromosomal abnormalities have major biologic and prognostic implications in leukemias. Cytogenetic information in typically hypoproliferative multiple myeloma (MM) is limited because of difficulties in obtaining analyzable metaphases. In this study, karyotypes and other known prognostic factors were analyzed in 155 newly diagnosed MM patients, entered on an intensive treatment program with two autotransplants. Complete remission (CR), event-free (EFS) and overall survival (OS) were analyzed using standard statistical methods. Abnormal cytogenetics were found in 39% of patients and were associated with a significantly lower CR rate (27% v 48%; P = .008). EFS and OS were inferior in patients with either partial or complete deletion of chromosome 13 or 11q abnormalities ("unfavorable" karyotype) when compared with the remaining patients (P < .001) who, as a group, had a similar prognosis irrespective of cytogenetic findings, ie, inevaluable, normal, or abnormal but without an "unfavorable" karyotype. The patients with abnormalities of both chromosomes 11 and 13 had a dismal prognosis with median EFS and OS of only 11 and 12 months, respectively. Significant associations were noted between an "unfavorable" karyotype and IgA isotype, elevated levels of beta-2 microglobulin (B2M, > or = 3 mg/L) and age > 60 years. On multivariate regression analysis, the absence of an "unfavorable" karyotype was the most significant variable associated with prolonged EFS and OS (P = .0001 and .0002, respectively). Other independent favorable variables were age less than 60 years, C-reactive protein (CRP) < or = 0.4 mg/dL and bone marrow plasmacytosis < or = 50% before treatment. On a multivariate analysis without cytogenetics, these same three standard parameters were identified as the only favorable variables. Patients not having all three standard favorable variables had a significantly lower CR rate (P = .03), EFS (P = .0001), and OS (P = .002) if an unfavorable karyotype was detected. We conclude that, in this program of uniformly treated MM patients, a poor prognosis was associated predominantly with abnormalities of chromosomes 11 and 13.

Nonrandom chromosome breakpoints at Xq26 and 2q33 characterize cemento-ossifying fibromas of the orbit

BACKGROUND

Cytogenetic reports of histologically benign fibroosseous lesions are rare, with only nine previously reported cases. None of these previous studies revealed consistent numerical or structural chromosome aberrations, and to the authors' knowledge, no karyotypic abnormalities in cemento-ossifying fibromas of the orbit have been reported.

METHODS

Short term in situ culture and Giesma-band chromosome methods were used to analyze three cementifying fibromas of the orbit: one from a 13-year-old African American male, one from a 14-year-old Hispanic male, and one from a 17-year-old white male.

RESULTS

Cytogenetic findings in these three cases revealed the presence of identical chromosomal breakpoints occurring in all three tumors at bands Xq26 and 2q33. Two of the tumors showed an identical t(X;2)(q26;q33) reciprocal translocation as the sole abnormality. The third tumor revealed an interstitial insertion of bands 2q24.2q33 into Xq26 as the sole abnormality.

CONCLUSIONS

The authors described new nonrandom breakpoints in fibroosseous lesions of the orbit, which can result from at least two different types of structural chromosomal aberrations. The identification of recurring breakpoints at Xq26 and 2q33 provides a new cytogenetic tumor marker for the identification of this tumor subtype. The sublocalization of breakpoints in this tumor should provide important information for the precise localization and characterization of genes involved in the histiogenesis of these lesions.

Nonrandom chromosome breakpoints at Xq26 and 2q33 characterize cemento-ossifying fibromas of the orbit

BACKGROUND

Cytogenetic reports of histologically benign fibroosseous lesions are rare, with only nine previously reported cases. None of these previous studies revealed consistent numerical or structural chromosome aberrations, and to the authors' knowledge, no karyotypic abnormalities in cemento-ossifying fibromas of the orbit have been reported.

METHODS

Short term in situ culture and Giesma-band chromosome methods were used to analyze three cementifying fibromas of the orbit: one from a 13-year-old African American male, one from a 14-year-old Hispanic male, and one from a 17-year-old white male.

RESULTS

Cytogenetic findings in these three cases revealed the presence of identical chromosomal breakpoints occurring in all three tumors at bands Xq26 and 2q33. Two of the tumors showed an identical t(X;2)(q26;q33) reciprocal translocation as the sole abnormality. The third tumor revealed an interstitial insertion of bands 2q24.2q33 into Xq26 as the sole abnormality.

CONCLUSIONS

The authors described new nonrandom breakpoints in fibroosseous lesions of the orbit, which can result from at least two different types of structural chromosomal aberrations. The identification of recurring breakpoints at Xq26 and 2q33 provides a new cytogenetic tumor marker for the identification of this tumor subtype. The sublocalization of breakpoints in this tumor should provide important information for the precise localization and characterization of genes involved in the histiogenesis of these lesions.

Centromeric instability of chromosome 1 resulting in multibranched chromosomes, telomeric fusions, and "jumping translocations" of 1q in a human immunodeficiency virus-related non-Hodgkin's lymphoma

BACKGROUND

Acquired immunodeficiency syndrome-related non-Hodgkin's lymphomas are associated with the B-cell chromosomal translocation t(8;14)(q24; q32). The most common secondary chromosome aberrations in these patients involve 1q and are believed to be associated with tumor progression. A mechanism for the origin of these 1q aberrations has not been demonstrated. To their knowledge, the authors report the first human immunodeficiency virus (HIV)-positive patient to have centromeric decondensation and multibranched chromosome aberrations of chromosomes 1 and 16 resulting in telomeric associations and "jumping translocations" of 1q.

METHODS

Tumor cells from peritoneal fluid of an HIV-positive patient were cultured for 24, 48, and 72 hours and analyzed by both conventional G-banding and fluorescence in situ hybridization.

RESULTS

G-band analysis showed a stemline with t(8;14)(q24;q32), but also showed the progression from centromeric decondensation to multibranched chromosome configurations of chromosomes 1 and 16. The interchange and duplications of chromosome arms resulted in the gain of extra copies of 1q material on a number of different chromosomes, but also the loss of 16q in at least one sideline and the formation of micronuclei. Fluorescence in situ hybridization analysis demonstrated that micronuclei predominantly involved chromosome 1 and, to a lesser extent, chromosome 16.

CONCLUSIONS

The cytogenetic findings in this unique case suggest that immunodeficiency may be a factor involved in centromeric instability, multibranching, and the progression to the subsequent formation of telomeric fusions and multiple unbalanced translocations of 1q (jumping translocations). The striking similarity of the centromeric instability in this patient to those with ICF syndrome (variable immunodeficiency, centromeric heterochromatin instability, and facial anomalies) suggests hypomethylation as the etiologic mechanism for the chromosome instability.

Low-grade astrocytoma with a complex four-breakpoint inversion of chromosome 8 as the sole cytogenetic aberration

We report a case of a low-grade astrocytoma in a 10-year-old boy in which the sole cytogenetic aberration was a complex four-breakpoint inversion of chromosome 8 with the karyotype designation 46,XY,der(8)inv(8)(p23q24)inv(8)(q11q21). Two protooncogenes on chromosome 8, MOS at 8q11 and MYC at 8q24, are located at or near the bands which correspond to two of the breakpoints in this inversion. The localization of the structural aberrations to four breakpoints on chromosome 8 provides a rare example of a solid tumor with structural aberrations limited to a single chromosome.

Cytogenetic findings in 200 patients with multiple myeloma

Cytogenetic studies were performed in 200 consecutive patients with multiple myeloma and related disorders. Structurally or numerically abnormal clones were found in 63 patients (32%), including 8 of 45 untreated patients (18%), and 55 of 155 treated patients (35%). The abnormal karyotypes generally showed numerous numerical and structural aberrations and in some patients multiple abnormal clones. The most striking feature of patients with hyperdiploid karyotypes was the finding of consistent recurring trisomies for chromosomes 3, 5, 7, 9, 11, 15, 19, and 21, cosegregating together in many cases. Monosomy for chromosome 13 was the most common chromosome loss, occurring in 18 abnormal patients (29%), while interstitial deletions involving band 13q14 occurred in an additional 9 patients, indicating a loss of all or part of chromosome 13 in a high percentage of patients with abnormal karyotypes (43%). Structural aberrations of chromosome 1 were most frequent, occurring in 30 of 63 patients (48%), and involved almost equally the short and long arms. The single most frequent chromosome breakpoint involved band 14q32 and was found in 21 patients (33%), including 11 patients with a 14q+ chromosome, 8 with t(11;14)(q13;q32), and 2 with t(8;14)(q24;132).

Trisomy 9: review and report of two new cases

Trisomy 9 is a relatively uncommon chromosome abnormality that may sometimes be seen in the nonmosaic state. We reviewed 23 mosaic and 15 nonmosaic cases of trisomy 9, including 2 new cases, in order to better define the prognosis and phenotype of this disorder. A recognizable trisomy 9 phenotype was identified and included a "bulbous" nose, microphthalmia, and dislocated limbs. Other nonspecific anomalies involving various organ systems were also common. With one exception, all survivors had severe mental impairment. Mosaicism for trisomy 9 predicted longer survival, but the degree of mosaicism in lymphocytes or fibroblasts did not predict survival or degree of impairment. Parental chromosome variations were not uncommon. In contrast to prior reports, no specific prognostic finding was identified. A meiotic origin with loss of a trisomic cell line in mosaic cases is suggested.

Chromosome instability in ICF syndrome: formation of micronuclei from multibranched chromosomes 1 demonstrated by fluorescence in situ hybridization

We report on a new patient with immunodeficiency, centromeric heterochromatin instability, and facial anomalies (the ICF syndrome). Studies with traditional cytogenetic methods demonstrate that aberrations in this syndrome primarily involve the centromeric regions of chromosomes 1 and 16. We applied fluorescence in situ hybridization (FISH) using "painting" probes for chromosomes 1 and 16 to document the progression of centromeric instability from simple decondensation aberrations to the subsequent formation of complex multibranched chromosomes 1, and finally to the interphase aberrations of nuclear projections and micronuclei involving both chromosomes 1 and 16. The loss of the large multibranched chromosome 1 configurations from the cells as micronuclei suggests that the centromeric aberrations subsequently interfere with normal chromosome movement at anaphase in ICF syndrome. Circular areas of counterstained chromatin were observed by FISH in the micronuclei corresponding to the intertwined segments of centromeric heterochromatin seen involving multibranched chromosomes 1 in the patient's G-banded chromosome study. The current hypothesis of recessive inheritance for this disorder suggests that the chromosomal aberrations are not a causative event in this syndrome; however, the chromosome aberrations are clearly an important basic diagnostic criterion.

High resolution mid-prophase human chromosomes induced by echinomycin and ethidium bromide

The antitumor antibiotic echinomycin (EM) was used in combination with ethidium bromide (EB) to induce high resolution mid-prophase chromosomes from amethopterin synchronized blood lymphocytes. With this combination of drugs, trypsin G-banded chromosomes showed over 1200 bands per haploid set in cells having a mid-prophase length of decondensation.

Pericentric inversion (2)(p15q35) in an alveolar rhabdomyosarcoma

We report a 7-year-old girl with a pericentric inversion of chromosome 2, inv(2)(p15q35), in a "solid variant" of alveolar rhabdomyosarcoma. The breakpoint in the long arm of chromosome 2 at band q35 is, at the cytogenetic level, identical to the breakpoint observed in the well-established reciprocal t(2;13)(q35;q14) associated with the alveolar subtype of rhabdomyosarcoma. In this case, however, no reciprocal translocation has occurred with chromosome 13 or any other chromosome, suggesting that the single critical breakpoint in alveolar rhabdomyosarcoma may be located at 2q35.

The effects of induction conditions on production of a soluble anti-tumor sFv in Escherichia coli

CC49 is a second generation monoclonal antibody (mAb) with high affinity to a pancarcinoma antigen, TAG-72. A single-chain Fv (sFv) of CC49 may have a role in managing human carcinomas. Most reported sFvs have been expressed as insoluble products that must be solubilized and renatured. Soluble sFv expression is advantageous as activity can be assayed directly from the periplasmic fraction. Also, gene-level immunoconjugates may not be amenable to refolding protocols. Using a vector that carries the tac promoter and omp A signal, we have examined the effects of four variables on the expression and accumulation of soluble CC49 sFv: (i) linker sequence joining VL and VH, (ii) isopropylthio-beta-D-galactoside concentration for induction, (iii) temperature, and (iv) the addition of non-metabolizable sugars to the medium. We have been able to demonstrate, using rapidly prepared periplasmic extracts, that the yield of soluble sFv improves by the addition of 0.4 M sucrose to the medium and by inducing expression with a very low concentration of IPTG (0.02-0.03 mM). Under these induction conditions periplasmic extracts demonstrate increased expression of the sFv, as shown by the larger amount of a 27 kDa band on SDS-polyacrylamide gel, and an increased ability to inhibit binding of the mAb CC49 to immobilized tumor extracts.

Clonal chromosome aberrations in a case of nodular fasciitis

We report a case of nodular fasciitis with clonal chromosome aberrations including a reciprocal t(3;15)(q21;q22) and interstitial deletion (13)(q14q21).

Potential diagnostic implications of breakpoints in the long arm of chromosome 8 in lipoblastoma

We report a case of lipoblastoma in a 17-month-old male patient with a pseudodiploid karyotype of 46,XY,der(14)t(8;14)(q11.2;q24). The tumor cells show two normal chromosome 8 homologs in addition to the extra 8q11.2-->qter segment, making it trisomic for the region 8q11.2-->qter, and monosomic for 14q24-->qter. Reports of chromosome studies in lipoblastoma are rare; however, a breakpoint in the long arm of chromosome 8q11-13 appears to be emerging as a consistent finding.

Deletion of the retinoblastoma gene in multiple myeloma

Deletion of the retinoblastoma gene (Rb-1) was found in more than 50% (12/23) of patients with multiple myeloma (MM) by fluorescence in situ hybridization (FISH). Myeloma cells were highly purified from bone marrow aspirates by flow cytometry and analyzed using probes specific for the Rb-1 gene and the centromeric region of chromosomes 13 and 21. Routine cytogenetics revealed abnormal chromosome 13 in only 17% (4/23) of these patients. No correlation between Rb-1 deletion and tumor stage, immunoglobulin isotype, anemia, serum beta-2 microglobulin levels, patient age or the extent of prior therapy was found. However, the high incidence of Rb-1 deletion detected by FISH suggests a role of this tumor suppressor gene in the biology of MM. Although allelic loss of the Rb-1 gene is unlikely to be the only genetic change necessary for the development of MM, it may be a relatively early event in MM unrelated to chemotherapeutic intervention. Since the Rb-1 gene suppresses IL-6 production and secretion, Rb-1 deletion may result in deregulation of IL-6 expression and hence expansion of IL-6 dependent myeloma clones.

Telomere fusion as a mechanism for the progressive loss of the short arm of chromosome 11 in an anaplastic Wilms' tumor

Wilms' tumor (WT) is associated with chromosomal deletions and loss of heterozygosity (LOH) of alleles at 11p13. The authors report the youngest known patient with diffusely anaplastic WT and, to their knowledge, the first case to demonstrate telomeric fusions as a chromosomal mechanism for the loss of bands 11p13 and 11p15 in WT. Recurrent clonal telomeric association (tas) initiated breakage/fusion cycles that resulted in deletions of chromosome bands 11p15, 11p13, and, subsequently, the entire short arm of chromosome 11. In addition, tas involving the long arms of chromosomes 7 and 9 resulted in the subsequent deletion of the long arm of chromosome 7. This report expands the spectrum of chromosomal mechanisms that can account for the loss of alleles on the short arm of chromosome 11 in WT by providing evidence that the progressive loss of critical chromosome regions associated with tumor suppression may occur as a result of chromosomal instability initiated by tas.

Chromosome aberrations in four ependymomas

Cytogenetic analysis of short-term cultures from three untreated and one recurrent ependymoma revealed clonal aberrations in three of the four tumors. A posterior fossa ependymoma from a 3-year-old male patient showed trisomy 11 as the sole clonal chromosome aberration. A recurrent spinal ependymoma from a 35-year-old male showed hypertriploid clones with abnormalities involving chromosomes 1p11,7q21, and 10p13. A 62-year-old male patient with a cerebellar ependymoma showed a hypodiploid stem-cell line with clonal structural aberrations of both the long and short arms of chromosome 1, an interstitial deletion of 2q, trisomy 7, and monosomy for chromosomes 11, 13, and 16. A 3-year-old female patient with posterior fossa ependymoma showed a normal 46,XX karyotype. Chromosome 1 aberrations appear to be the most consistent finding in this small series of tumors, with the net loss or rearrangement of chromosome 1 pter-->p22 material from two of the four tumors. These findings, in addition to a previously published case [1], suggest a possible role for genes on the short arm of chromosome 1 in the cytogenetic evaluation of ependymomas.

Duplication and deletion of chromosome band 2(p21p22) resulting from a familial interstitial insertion (2;11)(p21;p15)

Routine amniocentesis for advanced maternal age led to the prenatal diagnosis of a fetus with a karyotype of a 46,XX,del(2)(p21p22). At delivery the baby had holoprosencephaly as the major clinical finding, which has been associated with a deletion of band 2p21 in several other case reports. Chromosome studies of the parents showed a normal 46,XY karyotype in the father, and a balanced interstitial insertion 46,XX dir ins (11;2)(p15.1;p21p22) in the mother. Subsequent chromosome studies of other relatives documented a 23-year-old half-brother of the proposita with a partial trisomy for the segment deleted in the proposita. The half-brother showed the derivative chromosome 11 from the mother, resulting in a 46,XY,der(11)dup(2)(p21p22) karyotype. Major clinical findings include short stature, mild developmental delay, and behavior abnormalities. A half-sister of the proposita is also a balanced carrier of the dir ins (11;2) (p15.1;p21p22.2). The association of the deletion chromosome band 2p21 and the clinical finding of holoprosencephaly is further supported by the findings in this family.

Metastatic myxopapillary ependymoma: report of a case with fine-needle aspiration findings

A case of recurrent and metastasizing myxopapillary ependymoma of the sacral region in a 35-yr-old man is reported. Fifteen years after the original diagnosis, he presented with an abdominal mass, subcutaneous nodules in the previous surgical excision line, and bilateral inguinal lymph node enlargement. FNA cytology of the inguinal lymph nodes showed a poorly cohesive, highly cellular smear pattern exhibiting papillary formations and rosette-like structures composed of slim columnar cells having cytoplasmic processes without evidence of atypia. Histologic and ultrastructural findings confirmed the diagnosis. Chromosomal analysis was also done.

Karyotype evolution in a patient with Down syndrome and acute leukemia following a congenital leukemoid reaction

We report the serial cytogenetic study of a patient with Down syndrome who experienced a congenital leukemoid reaction, underwent a spontaneous remission within four months, and subsequently developed acute myeloid leukemia at 16 months. A blood chromosome study to rule out Down syndrome performed at age 24 days, during the leukemoid reaction, revealed a 47,XX,+21 karyotype. The diagnosis of acute leukemia was made at 16 months, at which time a chromosome study, on bone marrow, was performed. This analysis revealed a clonal karyotype of 47,XX,+21,-22,+der(22)t(1;22)(q21;q13) in all but one cell studied. The single apparently nonclonal cell showed a karyotype of 49,XX,+12,-13,-19,+der(19)t(19;?)(q11;?)x2,+21,+22. A third chromosome study at 19 months indicated the original leukemic clone with t(1;22) (q21;q13) had been replaced by the clone represented by the single cell with 49 chromosomes seen in the previous chromosome study. This case of an infant with Down syndrome and acute leukemia illustrated rapid evolution and a transitory nature to clonal chromosome aberrations while retaining AML morphology and course.

Ring chromosome 12 resulting from nonrandom telomeric associations with the short arm of chromosome 15 in a cerebellar astrocytoma

Ring chromosome 12 was found in an untreated cerebellar astrocytoma apparently resulting from nonrandom telomeric associations involving the short arm of chromosome 15, and both the long and short arms of chromosome 12. The clonal nonrandom telomeric associations of 15p to both ends of the chromosome 12 were transitory, but appear to be the precursor lesion in the evolution to ring chromosome 12 in this tumor. A multistep process in the formation of a ring chromosome resulting from nonrandom telomeric associations to both telomeres is illustrated.

Translocation (7;7)(p13;q21) in a Wilms' tumor

Reports of single chromosome aberrations in Wilms' tumors are rare, with most tumors being characterized by multiple complex karyotype aberrations. An 11-month-old female patient with Wilms' tumor and a derivative chromosome 7 resulting from t(7;7)(p13;q21) as the sole cytogenetic aberration is described.

High-resolution cytogenetic characterization of telomeric associations in ring chromosome 19

High-resolution cytogenetic studies of a normal individual with ring chromosome 19 indicate that, at the late-to-mid prophase level of band resolution, no apparent chromosomal material is missing, and that telomeric fusion/association, not deletion, is the cause of the ring chromosome formation. Sub-band analysis of the telomeric fusion shows thin chromatin filaments between the telomeres of some of the very elongated ring chromosomes, which cannot be resolved by metaphase chromosome analysis. The ring chromosome found in this individual shows evidence of the characteristic instability associated with ring chromosomes, including duplicated segments, double rings, and subsequent loss of the ring resulting in cells with monosomy 19. The lack of phenotypic effect and the unstable ring behavior, unlike previously reported patients with ring 19, support the formation of this ring by telomeric association.

Cytogenetic findings in a case of pediatric glioblastoma

We report a patient with glioblastoma multiforme (GBM) which showed stable and unstable telomeric associations involving the short arms of chromosomes 4 and 7. The karyotype was hyperdiploid, with chromosome numbers ranging from 84 to 87 in all cells, and showed a single stemline with variations in the number of marker chromosomes, teleomeric associations, and double minutes (dmin). The karyotype designation is 83-86,XX,-X,rea(X),-4,tas(4;7)(p16;?p22),der(6)t(6;?)(p21;?), -8, -9, der(9)t(9;?)(?p11;?), dup(9)(p12p23), -10 x 2, del(10)(p11), -11,del(11)(p11), -12, der(12)t(12;?) (p13;?),-13, -14 x 2,der(14)t(14;?) (p11;?), -16 x 2, -19, -21 x 2, -22 x 2, + 9-13mar, + dmin. Loss of the short arm of chromosome 10, structural aberrations of the short arm of chromosome 9, and dmin are consistent findings in GBM, whereas the high chromosome number is less common. Chromosome instability associated with the phenomenon of telomeric association/fusion has not been reported in GBM.