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Background: Copy number variation on chromosome 15q11.2 (BP1-BP2) causes a deletion of CYFIP1, NIPA1, NIPA2 and TUBGCP5. Furthermore, it also affects brain structure and elevates the risk for several neurodevelopmental disorders that are associated with dendritic spine abnormalities. In rodents, altered cyfip1 expression changes dendritic spine morphology, motivating analyses of human neuronal cells derived from induced pluripotent stem cells (iPSCs; iPSC-neurons). Methods: iPSCs were generated from a mother and her offspring, both carrying the 15q11.2 (BP1-BP2) deletion, and a non-deletion control. Gene expression in the deletion region was estimated using quantitative real-time PCR assays. Neural progenitor cells (NPCs) and iPSC-neurons were characterized using immunocytochemistry. Results:CYFIP1, NIPA1, NIPA2 and TUBGCP5 gene expression was lower in iPSCs, NPCs and iPSC-neurons from the mother and her offspring in relation to control cells. CYFIP1 and PSD-95 protein levels were lower in iPSC-neurons derived from the copy number variant-bearing individuals using Western blot analysis. Ten weeks after differentiation, iPSC-neurons appeared to show dendritic spines, and qualitative analysis suggested that dendritic morphology was altered in 15q11.2-deletion subjects compared with control cells. Conclusions: The 15q11.2 (BP1-BP2) deletion is associated with a reduced expression of four genes in iPSC-derived neuronal cells; it may also be associated with altered iPSC-neuron dendritic morphology.

The human X chromosome contains ∼ 1600 genes, about 15% of which have been associated with a specific genetic condition, mainly affecting males. Blue cone monochromacy (BCM) is an X-linked condition caused by a loss-of-function of both the OPN1LW and OPN1MW opsin genes. The cone opsin gene cluster is composed of 2-9 paralogs with 99.8% sequence homology and is susceptible to deletions, duplications, and mutations. Current diagnostic tests employ polymerase chain reaction (PCR)-based technologies; however, alterations remain undetermined in 10% of patients. Furthermore, carrier testing in females is limited or unavailable. High-resolution X chromosome-targeted CGH microarray was applied to test for rearrangements in males with BCM and female carriers from three unrelated families. Pathogenic alterations were revealed in all probands, characterized by sequencing of the breakpoint junctions and quantitative real-time PCR. In two families, we identified a novel founder mutation that consisted of a complex 3-kb deletion that embraced the cis-regulatory locus control region and insertion of an additional aberrant OPN1MW gene. The application of high-resolution X-chromosome microarray in clinical diagnosis brings significant advantages in detection of small aberrations that are beyond the resolution of clinically available aCGH analysis and which can improve molecular diagnosis of the known conditions and unravel previously unrecognized X-linked diseases.

We performed karyotype and array comparative genomic hybridization (aCGH) analyses on 177 prenatal samples, including 162 (92%) samples from fetuses with sonographic anomalies. Overall 12 fetuses (6.8%) had abnormal karyotype and 42 (23.7%) fetuses had abnormal microarray results: 20 (11.3%) with pathogenic copy number variations (CNVs), 16 with CNVs of uncertain clinical significance, 4 with CNVs establishing carrier status for recessive, X-linked, or susceptibility to late onset dominant disease, and two CNVs with pseudomosaicism due to in vitro cultural artifacts. For 23 pregnancies (13%), aCGH contributed important new information. Our results highlight the interpretation challenges associated with CNVs of unclear significance, incidental findings, as well as technical aspects. Array CGH analysis significantly improved the detection of genomic imbalances in prenatal diagnosis of pregnancies with structural birth defects.

A 16-year-old phenotypic female developed acute myeloblastic leukemia with a fulminant course very shortly after surgery and chemotherapy for a mixed germ cell tumor of the ovary. The karyotype (46, XY, 47, XY + 8) suggested de novo rather than therapy-associated leukemia. The relationship between germ cell tumors and leukemia, their common yolk sac derivation and the role of the Y chromosome are discussed. The idea that XY gonadal dysgenesis may be familial also is discussed.

Coffin-Siris syndrome is a multiple anomaly/mental retardation syndrome characterized by "coarse" facial appearance, hypoplastic or absent nails on the fifth digits, generalized hirsutism with sparse scalp hair, hypotonia, and developmental delay. Due to several reports of affected sibs with or without a mildly affected parent, both autosomal recessive and autosomal dominant inheritance have been suggested. All previous patients with well-documented Coffin-Siris syndrome are chromosomally normal, and the gene has not been mapped. We report on an infant with typical findings of Coffin-Siris syndrome who also has a de novo apparently balanced translocation of chromosomes 1 and 7, karyotype 46,XY,t(1;7)(q21.3;q34). The parental chromosomes are normal and none of the relatives have signs of Coffin-Siris syndrome. The breakpoints 1q21.3 and 7q34 are suggested as possible locations for a Coffin-Siris gene.

This study further defines the region of consistent deletion of chromosome 7 in uterine leiomyomas. We have examined 74 leiomyomas for allelic loss of markers spanning the 7q22 region defined by markers D7S518 and D7S471. Forty tumors with cytogenetically defined 7q deletions, twenty-nine tumors without cytogenetically visible 7q deletions, and five tumors with no cytogenetic information were examined for allelic loss of D7S518, D7S666, D7S515, D7S658, D7S496, D7S692, and D7S471. Loss of heterozygosity for one or more of these loci was observed in twenty-eight leiomyomas with cytogenetically defined 7q deletions and in three leiomyomas with a normal karyotype. Allelic loss of D7S666 was common and was observed in all twenty-three informative tumors with 7q deletions and in two tumors with normal karyotypes. This study indicates the presence of a tumor suppressor gene in close proximity to the D7S666 locus. Eight tumors followed an unusual pattern of allelic loss. These tumors showed retention of heterozygosity for at least one locus flanked by deleted loci. These results suggest the possibility that two discrete regions of deletion at 7q22 are involved in the development of a subset of leiomyomas.

Pallister-Killian syndrome (tetrasomy 12p) is a relatively rare aneuploidy syndrome characterized by the presence of mosaicism for an isochromosome 12p [i(12p)]. We report two new cases diagnosed following chorionic villus sampling and an abnormal ultrasound, respectively. Fluorescent in situ hybridization (FISH) was used to enumerate the number of interphase cells containing the isochromosome. The results of these studies illustrate the importance of the use of interphase FISH to detect the presence of the i(12p) in uncultured, non-dividing cells. A review of the literature identified 23 additional cases of Pallister-Killian syndrome diagnosed prenatally. Approximately 50 per cent of these cases were associated with the presence of a congenital diaphragmatic hernia. We suggest that a perinatal-lethal form of Pallister-Killian syndrome is underdiagnosed and recommend that all cases of prenatally detected diaphragmatic hernia be tested for Pallister-Killian syndrome using interphase FISH on uncultured amniocytes.

We report on our findings of 4 patients with mosaicism for a deletion of chromosome 15, most commonly associated with Prader-Willi syndrome (PWS). We examined a series of typical and atypical PWS patients in order to identify cytogenetically undetected deletions, using fluorescence in situ hybridization. In 4 of the patients analyzed we detected a deletion in 14-60% of peripheral blood leukocytes, using four commercially available probes. Our results indicate that mosaicism may play a role in the etiology of some PWS cases. These findings may be especially useful in patients who display discrepancies between clinical phenotype and established diagnostic criteria. Methylation and microsatellite polymorphism analyses of 2 patients with low-level mosaicism failed to identify the deletion. We propose that fluorescence in situ hybridization is the most effective method for detecting somatic mosaicism, since a large number of cells can be individually examined for the presence or absence of a specific deletion.

Pitt-Rogers-Danks syndrome (PRDS) is a rare, presumed autosomal recessive, syndrome with pre- and postnatal growth retardation, microcephaly, characteristic facial appearance, seizures, unusual palmar creases and developmental delay. Since the first description in 1984, only 7 cases have been reported. We report the identification of a 4p microdeletion in 2 new patients, who were previously diagnosed with PRDS, as well as the sibs in Pitt et al. [1984]. PRDS can no longer be considered autosomal recessive. Although our cases are attributable to a microdeletion in 4p16, it is uncertain if the critical region involves a single locus or multiple loci or to what extent this region overlaps with the critical region for Wolf-Hirschhorn syndrome.

Maternal uniparental disomy 15 (UPD15), responsible for approximately 25 per cent of Prader-Willi syndrome cases, is usually caused by maternal meiosis I non-disjunction associated with advanced maternal age. These cases may initially be detected as mosaic trisomy 15 during routine prenatal diagnostic studies. In such cases, PCR (polymerase chain reaction) microsatellite analysis of uncultured cells makes prospective prenatal diagnosis for UPD15 possible with results available in 2-4 days. We have performed molecular analyses on a series of seven cases of mosaic trisomy 15 identified in amniotic fluid (AF, n = 3) or chorionic villus samples (CVS, n = 4) from patients initially referred for advanced maternal age or abnormal triple screen. In all cases, the maternal ages wereor = 35 years and maternal meiosis I non-disjunction was documented as the cause of the trisomy in all informative cases (n = 5). Of the three case with mosaic trisomy 15 at amniocentesis, two showed the presence of the trisomy in the fetus. Molecular analysis showed one case with maternal UPD15 in the euploid cell line and one case with biparental inheritance. Both of these families elected to terminate the pregnancies based on the presence of true fetal mosaicism. In the third case, low-level trisomy 15 mosaicism in the amniotic fluid was not confirmed in a follow-up amniotic fluid sample and molecular analysis indicated biparental inheritance in the fetus. For the four trisomy 15 mosaics detected at CVS, molecular analysis was performed on direct amniotic fluid cell lysates for prospective diagnosis of UPD at 14-16 weeks' gestation. Follow-up cytogenetic analysis of the amniotic fluid in all four cases was normal, indicating confined placental mosaicism. Molecular analysis showed one of these four cases to have maternal heterodisomy 15. Based on the likelihood of Prader-Willi syndrome due to maternal UPD15, the couple chose to terminate the pregnancy. The total of two of seven cases of trisomy 15 mosaicism resulting in UPD15 is consistent with the theoretical expectation of one-third and indicates a high risk of UPD in such pregnancies. Therefore, UPD testing should be offered in all cases of mosaic trisomy 15 encountered in CVS or amniocentesis.

In order to further our understanding of the epigenetic modifications of DNA and its role in imprinting, we examined DNA methylation patterns of human tissues of uniparental origin. We used complete hydatidiform moles (CHM), which are totally androgenetic conceptions, to examine the paternal methylation pattern in the absence of a maternal contribution and we used ovarian teratomas to represent the maternal counterpart. We carried out an analysis of DNA methylation of a gene which has been shown to contain sites which are differentially methylated in a parent-specific fashion. The gene, ZNF127, is located on chromosome 15q11-q13 in the region associated with Prader-Willi and Angelman syndromes. The parent-of-origin DNA methylation has been postulated to reflect the presence of an imprint and recent studies have confirmed that ZNF127 is differentially expressed only from the paternal chromosome. We identified a unique pattern of hyper- and hypomethylated sites in androgenetic conceptions which was nearly identical to the paternal pattern found in sperm. This may represent the paternal germ-line methylation imprint. We also studied partial hydatidiform moles, non-molar triploid conceptions, normal chorionic villi, and somatic tissue. These all demonstrated a modified DNA methylation pattern characteristic of normal chorionic villi with only limited findings of the imprint. Our results suggest that human androgenetic conceptions may provide an excellent model to analyze epigenetic DNA modifications, such as methylation, in imprinted genes. The paternal allele-specific methylation imprint will also be useful clinically to confirm the androgenetic nature of suspected molar conceptions in which parental blood samples may not be available.

We report a 38-year-old gravida 3, para 3, white female with an unremarkable history and normal amniocentesis, who delivered a male infant with a large pedunculated and ulcerated tumor by vaginal delivery. A portion of the tumor was sheared and expelled with the normal placenta at the time of delivery. The biopsy of the infant mass and the expelled tissue showed histologic features of a small round cell tumor with immunohistochemical features of a primitive neuroectodermal tumor (PNET). The infant eventually died at the age of 4 weeks as a result of extensive dissemination of tumor. The mother had postpartum bleeding, and fractional dilation and curettage procedures at 6 weeks and 4 months after delivery revealed tumor similar to that of the infant. The mother underwent radical hysterectomy and bilateral salpingo-oophorectomy, which revealed a neoplasm at the junction of the lower uterine segment and cervix. Fluorescentin situhybridization (FISH) study of both the infant's tumor and the mother's uterine tumor showed positivity for the Y chromosome by using a classical α-satellite Y chromosome-specific probe. These findings support the hypothesis that the tumor was transferred from the fetus to the mother.

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are distinct mental retardation syndromes caused by paternal and maternal deficiencies, respectively, in chromosome 15q11-q13. Approximately 70% of these patients have a large deletion of approximately 4 Mb extending from D15S9 (ML34) through D15S12 (IR10). To further characterize the deletion breakpoints proximal to D15S9, three new polymorphic microsatellite markers were developed that showed observed heterozygosities of 60%-87%. D15S541 and D15S542 were isolated from YAC A124A3 containing the D15S18 (IR39) locus. D15S543 was isolated from a cosmid cloned from the proximal right end of YAC 254B5 containing the D15S9 (ML34) locus. Gene-centromere mapping of these markers, using a panel of ovarian teratomas of known meiotic origin, extended the genetic map of chromosome 15 by 2-3 cM toward the centromere. Analysis of the more proximal S541/S542 markers on 53 Prader-Willi and 33 Angelman deletion patients indicated two classes of patients: 44% (35/80) of the informative patients were deleted for these markers (class I), while 56% (45/80) were not deleted (class II), with no difference between PWS and AS. In contrast, D15S543 was deleted in all informative patients (13/48) or showed the presence of a single allele (in 35/48 patients), suggesting that this marker is deleted in the majority of PWS and AS cases. These results confirm the presence of two common proximal deletion breakpoint regions in both Prader-Willi and Angelman syndromes and are consistent with the same deletion mechanism being responsible for paternal and maternal deletions. One breakpoint region lies between D15S541/S542 and D15S543, with an additional breakpoint region being proximal to D15S541/S542.

The abnormal phenotype and/or mental retardation seen in persons with small marker X (mar(X)) chromosomes has been hypothesized to be due to the loss of the X inactivation center (XIC) at Xq13.2, resulting in two active copies of genes in the pericentromeric region. In order to define precisely the DNA content of mar(X) chromosomes and to correlate phenotype with karyotype, we studied small mar(X) chromosomes, using FISH with probes in the juxtacentromeric region. One of the probes was a 40-kb genomic cosmid for the XIST gene, which maps to the smallest interval known to contain the XIC and is thought to be involved in X inactivation. Our findings reveal that small mar(X) chromosomes do not include the XIC and therefore cannot be subject to X inactivation, supporting the premise that abnormal dosage of expressed genes in the pericentromeric region of the X generates the aberrant phenotype seen in patients with small mar(X) chromosomes.

Cat eye syndrome is associated with a partial tetrasomy 22q and can be inherited. The authors have evaluated the marker chromosome in a proband and his mother by cytogenetic banding techniques to verify the dicentric chromosomal rearrangement and by fluorescence in situ hybridization to confirm the involvement of 22. The mother also had an affected offspring with an unrelated aneuploidy, trisomy 21.

This report presents cytogenetic data on three cases of malignant ovarian germ cell tumors. All were diagnosed as malignant teratoma; case 1 with yolk sac elements; case 2 with elements of endodermal sinus tumor, embryonal carcinoma, and choriocarcinoma; and case 3 with yolk sac elements and embryonal carcinoma. Metaphase cells from each tumor, and normal tissue from the host, were karyotyped and scored for centromeric heteromorphisms in an attempt to determine the mechanism of origin. The karyotypes were 79,XXX,+1,+3,-6,+8,+12,+14,-15,+17, +20,+21,+22;49,XX,+8,+12,+22; and 48,XX,+3,+14, respectively. The analysis of centromeric heteromorphisms and DNA fingerprints of host and teratoma using the M13 probe revealed that one case originated from a germ cell before the first meiotic division. Normal host tissue was not available in case 2, but several centromeric markers were heterozygous in the tumor, indicating either meiosis I error or complete failure of germ cell meiosis. In the third case the centromeric heteromorphisms that were heterozygous in the host appeared to be homozygous for certain chromosomes and heterozygous for others in the tumor. These results suggest that germ cell teratomas could arise by the fusion of two ova.

The main purpose of this study was to determine whether there is any correlation between the cytogenetic abnormalities and histology in uterine leiomyomas.A total of 93 benign uterine leiomyomas were included in the study. The majority (88 of 93) were classified as typical benign leiomyomas, four as cellular, and one as atypical symplastic.A normal chromosome complement (46,XX) was observed in approximately 50% of the cases (41 of 93). Seventeen leiomyomas did not grow sufficiently in culture to yield cells for chromosome analyses. Of the 35 cases with clonal abnormalities, 28 could be divided into four major subgroups, each representing one of the most common abnormalities observed, such as those of chromosomes 1, 7, and 13, and t(12;14).Our findings indicate that approximately 50% of leiomyomas show clonal abnormalities, which can be subdivided into four different major categories; four of five (80%) of the atypical leiomyomas showed clonal chromosome abnormalities, which in one case were complex. The results indicate that different specific chromosome abnormalities may characterize the same tumor type.

Cytogenetic analysis of short-term cultures from 35 leiomyomas of the female genitourinary tract showed abnormal karyotypes in 14 cases. In 11 of 14 aberrant tumors, normal cells were also observed. Structural changes were most frequent, resulting in modal chromosome numbers in the diploid range. Our data confirm preferential breakpoint clusters at 7q, 12q14-15, and 14q23-24, mainly resulting from consistent, specific chromosome rearrangements such as t(12;14)(q14-15;q23-24) and del(7)(q21) or del(7)(q22q32). Together with previously published cases, we describe trisomy 12, ring chromosomes, and monosomy 22 as new additional recurrent findings in myomas. Statistical analyses of possible coherencies between tumor karyotype (abnormal versus normal) and clinicopathologic data, as well as age of the patients, menopausal status, and tumor size showed no correlations.

A squamous cell carcinoma in situ arose in an ovarian mature teratoma (ie, dermoid cyst) in a 62-year-old woman. Flow cytometric DNA content analysis of paraffin-embedded in situ carcinoma showed a normal DNA content with moderate to high proliferative activity (S-phase fraction estimate, 16% to 18%). Cytogenetic analysis of the in situ cancer and the benign cystic portion of the tumor revealed a 46,XX karyotype. In addition, the benign cystic portion of the tumor revealed homozygous chromosomal heteromorphisms, compared with heterozygous markers found in peripheral blood lymphocytes. These results show that this squamous cell carcinoma in situ was euploid and suggest that the mature cystic teratoma was derived from a single germ cell after meiosis I.

Two dimensional DNA electrophoresis (2D-DE) was used to map the variable (VH) region of the human heavy chain immunoglobulin gene cluster. Seventy-six VH gene segments were mapped to specific SfiI, BssHI and NotI fragments by 2D-DE. We have determined that a common insertion/deletion polymorphism of 80 kb, involving three VH gene segments, occurs in the VH region. The physical map suggests that the evolution of the human IGH gene complex involved duplication of blocks containing different VH families. This physical map will allow comparison of the usage of VH loci in human ontogeny with their proximity to the CH region. Knowledge of the germline repertoire of a particular DNA source studied in essential as the number of the dispersed VH gene segments of VH families, especially of the VH5 family, is variable. 2D-DE, as illustrated here for the IGH gene cluster, has general application in the development of large scale physical maps of gene and repeat families.

21108 Background: Preliminary data from a phase III trial of adjuvant traztuzumab (BCIRG, SABCS 2005, abstract 1045) suggested that co-amplification of the genes for HER2 and topisomerase II alpha (TOP2A) on chromosome 17 resulted in improved disease free survival with chemotherapy regimens containing both and anthracycline and traztuzumab. We sought to determine if co-amplification of HER2 and TOP2A was a predictor of response and benefit (or lack thereof) to herceptin containing chemotherapy in the metastatic setting, since few women receive both therapies concurrently for MBC. Methods: A tissue mircoarray (TMA) with 3-fold redundancy was constructed using 0.6mm cores from primary or metatstatic paraffin embedded tumor from 124 cases from Magee-Women's Hospital which were Her2 2+ or 3+ by IHC, or amplified by FISH, on pathology report. Four micron thick TMA sections were used for HER2 immunohistochemical (CB11 monoclonal antibody, Ventana Medical Systems, Tucson, AZ) and HER2 and TOP2A FISH analysis (HER2/CEP 17 and TOP2A/CEP 17 dual color probes from Vysis Inc. Downers Grove, IL). HER2 (or TOP2A) gene to chromosome 17 ratios of 2.0 or more was considered as amplification. Results: Tissue blocks from 52 tumors delivered clearly interpretable amplification for Her2 by FISH on reanalysis. The remaining 72 tumors are undergoing further reanalysis. Of the 52 tumors with Her2 amplification, 15 (29%) had co- amplification of TOP2A. Median survival was 44 months (95% CI, 31–69) for women with TOP2A coamplified tumors and 35 months (95% CI, 29- 63) for women with non-coamplified tumors (p=0.448, NS). Median time to progression on first therapy was 17 months (95% CI, 14–20) for women with TOP2A coamplified tumors and 15 months (95% CI, 12–17) for women with non-coamplified tumors (p=0.939, NS) Conclusions: In this analysis, TOP2A and HER2 gene co-amplification did not correlate with worse TTP on first metatstatic therapy or worse OS from metatstatic disease. No significant financial relationships to disclose.

Partial hydatidiform mole differs from complete mole by its focal distribution, its slower transformation, the presence of an embryo or fetus, and the triploid karyotype. Nineteen pathologically proved cases are presented. Partial mole can be diagnosed by a combination of the following sonographic findings: (a) greatly enlarged placenta relative to the size of the uterine cavity, (b) cystic spaces within the placenta ("molar placenta"), which may not always be present, (c) an amniotic cavity (gestational sac), either empty or containing amorphous fetal echoes, and (d) a well-formed but growth-retarded fetus, either dead or alive.

Having delineated the complete and the partial hydatidiform moles as 2 separate entities on the basis or morphology and cytogenetics, the authors studied 201 molar pregnancies at the Magee-Womens Hospital in an attempt to characterize the clinicopathologic profile of the partial mole syndrome. This was done mainly by comparison and contrast with the established and more familiar syndrome of the classic complete mole. The partial mole syndrome displays most of the pathologic and clinical features of the classic mole and seems to represent a milder, dilute version of the latter. This applies to placental morphology, to the fate of the embryo/fetus, and to human chorionic gonadotropin (hCG) levels as well as to the incidence and severity of clinically persistent trophoblastic disease. Preeclampsia can be equally severe in both syndromes, but tends to occur later in patients with partial mole. No metastatic disease was encountered in association with partial moles and no case of overt choriocarcinoma has yet been described. The occurrence of trophoblastic disease (as determined by postoperative hCG titers) following partial moles requires further inquiry, including study of the pathology of the underlying lesion(s), which remain virtually unexplored.

Cytogenetic and morphologic analysis of 23 hydatidiform moles allowed the division into at least two syndromes: (1) the syndrome of complete (classical) mole is without an ascertainable embryo/fetus, gives a diploid karyotype, and manifests a progressive fluid engorgement of the villi as well as a gross, haphazardly distributed trophoblastic hyperplasia; (2) the syndrome of partial (incomplete) mole has an ascertainable fetus (alive or dead), gives a triploid karyotype, and exhibits a slowly progressing hydatidiform swelling in the presence of functioning villous capillaries that spares many villi; trophoblastic immaturity is constant and focal hyperplasia is inconspicuous but present. A single case of diploid mole with unusual morphologic features, complete with a fetus, may herald yet another syndrome. Human chorionic gonadotropin levels were initially high in practically all cases. There was no malignant trophoblastic disease in this small series, but a plea is made that partial moles be followed carefully in order to establish their relation to choriocarcinoma.

Hydatidiform moles studied with respect to cytogenetics and morphologic constitution were divisible into two syndromes: (1) complete, classical mole giving a 46 XX karyotype and (2) partial mole with an ascertainable embryo/fetus, dead or alive, giving a triploid karyotype. The complete moles undergo early and total hydatidiform change from edema to central cistern formation, the embryos proper having perished before the establishment of a functioning circulation. Trophoblastic hyperplasia is conspicuous and the connection of this group to chorioncarcinoma is well established. In the partial moles there is a slow hydatidiform change that affects only some of the villi, but which seems to follow along the same lines as in complete moles. There is focal moderate trophoblastic hyperplasia, villous "trophoblastic inclusions" (that appear in triploids only), and maze-like central cisterns in the later cases. The partial mole, 46 XX, partakes of morphologic characteristics of both main syndromes and may represent an unusual syndrome of its own. The two main syndromes can now be distinguished morphologically and the question of the association of the partial mole with chorioncarcinoma has now to be further studied.

21051 Background: Guidelines for the interpretation of Her2 testing by FISH in determining therapy for Her2 positive metatstatic breast cancer generally suggest that only women with Her2 to chromosome 17 (CEP 17) amplification ratios of greater than 2.0 will benefit from traztuzumab. However, hyperploidy of chromosome 17 may lead to increased Her2 copy number despite a normal HER2/CEP 17 ratio, which may also predict response. We sought to examine hyperploid frequency in a well defined Her2 positive MBC population. We also sought to determine the time to progression (TTP) on first chemotherapy for MBC in such women, as well as their overall survival (OS) with MBC. Methods: A tissue mircoarray (TMA) with 3-fold redundancy was constructed using 0.6mm cores from primary or metatstatic paraffin embedded tumor from 124 cases which were Her2 2+ or 3+ by IHC, or amplified by FISH, on pathology report. Four micron thick TMA sections were used for HER2 IHC and HER2 FISH analysis. HER2/CEP 17 ratios of 2.0 or more was considered as amplification. If the tumor was 2+ or 3+ by IHC, greater than or equal to 3 signals for chromosome 17 were seen in a majority of cell nuclei, and the HER2/CEP17 ratio was less than 2.0, the tumor was considered hyperploid Her2 FISH negative. Results: Tissue blocks from 52 tumors delivered clearly interpretable amplification for Her2 by FISH. An additional 10 tumors (8%) were hyperploid, IHC positive (2+ or 3+), and FISH negative. Median survival (Kaplan-Meier) was 39 months (95% CI, 21–62) for women with hyperploid FISH negative tumors and 41 months (95% CI, 25–53) for women with FISH positive tumors (p=0.63, NS, Wilcoxon). Median time to progression (Kaplan-Meier) on first therapy for metastatic disease was 14 months (95% CI, 8–20) for hyperploid FISH negative tumors and 15 months (95% CI, 12–18) for women with FISH positive tumors (p=0.41, NS, Wilcoxon). Conclusions: In this analysis, women with hyperploid Her2 FISH negative IHC positive tumors had similar TTP and OS as women with Her2 FISH positive tumors. These women, although Her2 FISH negative, appeared to respond well to traztuzumab. These provocative results should be repeated on larger data sets. No significant financial relationships to disclose.