Whole-genome Single Nucleotide Polymorphism Array Research Articles

Molecular Breeding of Water-Saving and Drought-Resistant Rice for Blast and Bacterial Blight Resistance.

Rice production is often affected by biotic and abiotic stressors. The breeding of resistant cultivars is a cost-cutting and environmentally friendly strategy to maintain a sustainable high production level. An elite water-saving and drought-resistant rice (WDR), Hanhui3, is susceptible to blast and bacterial blight (BB). This study was conducted to introgress three resistance genes (Pi2, xa5, and Xa23) for blast and BB into Hanhui3, using marker-assisted selection (MAS) for the foreground selection and a whole-genome single-nucleotide polymorphism (SNP) array for the background selection. As revealed by the whole-genome SNP array, the recurrent parent genome (RPG) recovery of the improved NIL was 94.2%. The resistance levels to blast and BB of the improved NIL and its derived hybrids were higher than that of the controls. In addition, the improved NIL and its derived hybrids retained the desired agronomic traits from Hanhui3, such as yield. The improved NIL could be useful to enhance resistance against biotic stressors and produce stable grain yields in Oryza sativa subspecies indica rice breeding programs.

Genetic Identity Based on Whole-Genome SNP Array Data of Weedy Rice in Nagano, Japan

The rice production system in Japan is changing due to the aging of rice farmers, shortage of labor, mechanization, and increase of large-scale rice fields and increased application of direct sowing, all of which contribute to the lack of sophisticated weed management practices. Because the changing production system has not improved and likely worsened weed management practices, weedy rice (Oryza sativa L.) has become a serious threat to rice production in Japan. We analyzed weedy rice accessions from Nagano, the central part of Japan, and other rice accessions to elucidate the origin of this weedy rice using a whole-genome single nucleotide polymorphism (SNP) array. For developing sustainable weedy rice management practices, the elucidation of the origin of re-emerging weedy rice is crucial. Population genetic analysis indicated that weedy rice in Nagano was phylogenetically independent from the local red rice cultivar with low genetic diversity. Past and recently re-emerging weedy rice ecotypes in Nagano shared a similar genetic background which implies the evolution of weedy rice by severe natural selection. Window-based FST and selection sweep analysis revealed the divergence of some of the known key domestication-related genes, such as shattering gene sh4 and qsh1, of weedy rice from domesticated rice cultivars.

Genetic and epigenetic analyses guided by high resolution whole-genome SNP array reveals a possible role of CHEK2 in Wilms tumour susceptibility.

Wilms tumour (WT), the most frequent malignant childhood renal tumour, shows a high degree of genetic and epigenetic heterogeneity. Loss of imprinting on chromosome 11p15 is found in a large fraction of cases and mutations in a few genes, including WT1, CTNNB1, WTX, TP53 and, more recently, SIX1, SIX2 and micro RNA processing genes (miRNAPGs), have been observed. However, these alterations are not sufficient to describe the entire spectrum of genetic defects underlying WT development. We inspected data obtained from a previously performed genome-wide single nucleotide polymorphism (SNP) array analysis on 96 WT samples. By selecting focal regions commonly involved in chromosomal anomalies, we identified genes with a possible role in WT development, based on the prior knowledge of their biological relevance, including MYCN, DIS3L2, MIR562, HACE1, GLI3, CDKN2A and CDKN2B, PALB2, and CHEK2. The MYCN hotspot mutation c.131C>T was detected in seven cases (7.3%). Full sequencing of the remaining genes disclosed 16 rare missense variants and a splicing mutation. Most of these were present at the germline level. Promoter analysis of HACE1, CDKN2A and CDKN2B disclosed partial methylation affecting HACE1 in a consistent fraction of cases (85%). Interestingly, of the four missense variants identified in CHEK2, three were predicted to be deleterious by in silico analyses, while an additional variant was observed to alter mRNA splicing, generating a functionally defective protein. Our study adds additional information on putative WT genes, and adds evidences involving CHEK2 in WT susceptibility.

Clonal composition of human ovarian cancer based on copy number analysis reveals a reciprocal relation with oncogenic mutation status

Intratumoral heterogeneity of cancer cells remains largely unexplored. Here we investigated the composition of ovarian cancer and its biological relevance. A whole-genome single nucleotide polymorphism array was applied to detect the clonal composition of 24 formalin-fixed, paraffin-embedded samples of human ovarian cancer. Genome-wide segmentation data consisting of the log2 ratio (log2R) and B allele frequency (BAF) were used to calculate an estimate of the clonal composition number (CC number) for each tumor. Somatic mutation profiles of cancer-related genes were also determined for the same 24 samples by next-generation sequencing. The CC number was estimated successfully for 23 of the 24 cancer samples. The mean ± SD value for the CC number was 1.7 ± 1.1 (range of 0–4). A somatic mutation in at least one gene was identified in 22 of the 24 ovarian cancer samples, with the mutations including those in the oncogenes KRAS (29.2%), PIK3CA (12.5%), BRAF (8.3%), FGFR2 (4.2%), and JAK2 (4.2%) as well as those in the tumor suppressor genes TP53 (54.2%), FBXW7 (8.3%), PTEN (4.2%), and RB1 (4.2%). Tumors with one or more oncogenic mutations had a significantly lower CC number than did those without such a mutation (1.0 ± 0.8 versus 2.3 ± 0.9, P = 0.0027), suggesting that cancers with driver oncogene mutations are less heterogeneous than those with other mutations. Our results thus reveal a reciprocal relation between oncogenic mutation status and clonal composition in ovarian cancer using the established method for the estimation of the CC number.

Molecular Breeding of Rice Restorer Lines and Hybrids for Brown Planthopper (BPH) Resistance Using the Bph14 and Bph15 Genes.

BackgroundThe development of hybrid rice is a practical approach for increasing rice production. However, the brown planthopper (BPH), Nilaparvata lugens Stål, causes severe yield loss of rice (Oryza sativa L.) and can threaten food security. Therefore, breeding hybrid rice resistant to BPH is the most effective and economical strategy to maintain high and stable production. Fortunately, numerous BPH resistance genes have been identified, and abundant linkage markers are available for molecular marker-assisted selection (MAS) in breeding programs. Hence, we pyramided two BPH resistance genes, Bph14 and Bph15, into a susceptive CMS restorer line Huahui938 and its derived hybrids using MAS to improve the BPH resistance of hybrid rice.ResultsThree near-isogenic lines (NILs) with pyramided Bph14 and Bph15 were obtained by molecular marker-assisted backcross (MAB) and phenotypic selection. The genomic components of these NILs were detected using the whole-genome SNP (Single nucleotide polymorphism) array, RICE6K, suggesting that the recurrent parent genome (RPG) recovery of the NILs was 87.88, 87.70 and 86.62 %, respectively. BPH bioassays showed that the improved NILs and their derived hybrids carrying homozygous Bph14 and Bph15 were resistant to BPH. However, the hybrids with heterozygous Bph14 and Bph15 remained susceptible to BPH. The developed NILs showed no significant differences in major agronomic traits and rice qualities compared with the recurrent parent. Moreover, the improved hybrids derived from the NILs exhibited better agronomic performance and rice quality compared with the controls under natural field conditions.ConclusionsThis study demonstrates that it is essential to stack Bph14 and Bph15 into both the maternal and paternal parents for developing BPH-resistant hybrid rice varieties. The SNP array with abundant DNA markers is an efficient tool for analyzing the RPG recovery of progenies and can be used to monitor the donor segments in NILs, thus being extremely important for rice molecular breeding.

Implementation of a High-Resolution Single-Nucleotide Polymorphism Array in Analyzing the Products of Conception.

To demonstrate the value of a whole-genome high-resolution single-nucleotide polymorphism (SNP) array for the elucidation of genetic causes underlying pregnancy loss. The SNP array combined with SNPs and oligonucleotide probes was used to examine 60 samples of products of conception, including chorionic villi, fetal parts, and fetal blood. The SNP array yielded a 38.3% (23/60) abnormality rate. In addition to the most common aneuploidy, it detected 16.7% additional aberrations involving copy number variation, triploidy, loss of heterozygosity or low-level mosaicism. This whole-genome high-resolution SNP array not only provides copy number information but also identifies the heterozygosity status, which facilitates the discovery of the novel genetic alterations associated with pregnancy failure and improves the management of subsequent pregnancies.

Genome-Wide Single-Nucleotide Polymorphism Array Analysis Improves Prognostication of Acute Lymphoblastic Leukemia/Lymphoma

Chromosomal abnormalities are important for the risk stratification of acute lymphoblastic leukemia/lymphoma (ALL). However, approximately 30% of pediatric and 50% of adult patients lack abnormalities with clinical relevance by traditional cytogenetic analysis. We integrated cytogenetic, fluorescence in situ hybridization, and whole-genome single-nucleotide polymorphism array results from 60 consecutive clinical ALL cases. By cytogenetic and/or fluorescence in situ hybridization analyses, recurring abnormalities with clinical relevance were observed in 33 B-cell ALL (B-ALL), including t(9;22), hyperdiploidy, KMT2A translocation, ETV6-RUNX1, intrachromosomal amplification of chromosome 21, near haploidy or low hypodiploidy, and t(8;22). Single-nucleotide polymorphism array analysis found additional aberrations with prognostic or therapeutic implication in 21 B-ALL and two T-cell ALL, including IKZF1 deletion, intrachromosomal amplification of chromosome 21 (one case with a normal karyotype), low hypodiploidy (two cases with a normal karyotype), and one case each with fusion genes ETV6-NTRK3, CRLF2-P2RY8, NUP214-ABL1, and SET-NUP214. IKZF1 deletion was noted in nine B-ALL with t(9;22), one B-ALL with t(4;11), five B-ALL with a normal karyotype, and three B-ALL with nonrecurring karyotypic abnormalities. Combining single-nucleotide polymorphism array with chromosome and fluorescence in situ hybridization assays, the detection rate for clinically significant abnormal results increased from 56% to 75%. Whole-genome single-nucleotide polymorphism array analysis detects cytogenetically undetectable clinicallysignificant aberrations and should be routinely applied at diagnosis of ALL.

Development and Validation of a High-Density SNP Genotyping Array for African Oil Palm

High-density single nucleotide polymorphism (SNP) genotyping arrays are powerful tools that can measure the level of genetic polymorphism within a population. To develop a whole-genome SNP array for oil palms, SNP discovery was performed using deep resequencing of eight libraries derived from 132 Elaeis guineensis and Elaeis oleifera palms belonging to 59 origins, resulting in the discovery of >3 million putative SNPs. After SNP filtering, the Illumina OP200K custom array was built with 170 860 successful probes. Phenetic clustering analysis revealed that the array could distinguish between palms of different origins in a way consistent with pedigree records. Genome-wide linkage disequilibrium declined more slowly for the commercial populations (ranging from 120 kb at r2 = 0.43 to 146 kb at r2 = 0.50) when compared with the semi-wild populations (19.5 kb at r2 = 0.22). Genetic fixation mapping comparing the semi-wild and commercial population identified 321 selective sweeps. A genome-wide association study (GWAS) detected a significant peak on chromosome 2 associated with the polygenic component of the shell thickness trait (based on the trait shell-to-fruit; S/F %) in tenera palms. Testing of a genomic selection model on the same trait resulted in good prediction accuracy (r = 0.65) with 42% of the S/F % variation explained. The first high-density SNP genotyping array for oil palm has been developed and shown to be robust for use in genetic studies and with potential for developing early trait prediction to shorten the oil palm breeding cycle.

Genomic aberrations of myeloproliferative and myelodysplastic/myeloproliferative neoplasms in chronic phase and during disease progression.

Myeloproliferative neoplasms (MPN) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) may transform into secondary myelofibrosis (MF) or evolve into acute myeloid leukemia (AML). The genetic mechanisms underlying disease progression in MPN and MDS/MPN patients remain unclear. The purpose of this study was to investigate sequential genomic aberrations identified by single nucleotide polymorphism array (SNP-A)-based karyotyping that can detect cryptic aberrations or copy neutral loss of heterozygosity (CN-LOH) in the chronic phase and during disease progression of MPN and MDS/MPN patients. The study group included 13 MPN and four MDS/MPN patients (seven polycythemia vera (PV); four essential thrombocythemia (ET); two MPN-unclassifiable (MPN-U); one chronic myelomonocytic leukemia (CMML); one atypical chronic myeloid leukemia, BCR-ABL1 negative (aCML); and two MDS/MPN-unclassifiable (MDS/MPN-U)). Among them, five patients (two PV, two MPN-U, and one MDS/MPN-U) progressed to MF and three patients (one CMML, one aCML, and one MDS/MPN-U) transformed to AML. The median follow-up period was 70 months (range, 7-152). Whole-genome SNP-A (SNP 6.0; Affymetrix, Santa Clara, CA, USA)-based karyotyping and JAK2 mutation analysis were performed according to the manufacturer's instructions. SNP-A showed 19 kinds of genomic aberrations, including seven gains, eight deletions, and four CN-LOH. CN-LOH of 9p involving JAK2 was the most common aberration, followed by 5q deletion and 9p gain. The incidence of genomic changes identified by SNP was not different in patients with disease progression (75%), compared with those without disease progression (56%) (P = 0.4). However, when excluding 9p CN-LOH, the incidence of genomic changes was significantly higher in patients with disease progression than in patients without disease progression (63% and 0%, respectively, P = 0.01). Among eight patients with disease progression, two patients (two MPN-U) showed abnormal SNP-A results, whereas metaphase cytogenetics (MC) analysis showed normal results at diagnosis and during follow-up. In nine patients without disease progression, SNP-A did not show any genomic aberrations except for 9p CN-LOH. In three patients (one PV, one aCML, and one MDS/MPN-U), clonal evolutions were identified by both MC and SNP-A according to disease progression. One PV patient who progressed to MF at 45 months after diagnosis showed sequential genomic changes from 9p CN-LOH to 9p gain by SNP-A. Results of JAK2 mutation analysis were variable depending on the patient. Most of the patients with 9p CN-LOH or 9p gain showed more than 50% of the JAK2 mutant alleles. In one patient (MDS/MPN-U) evolving to AML, the number of JAK2 mutant alleles decreased according to disease progression. This study suggests sequential genomic changes identified by SNP-A may be associated with disease progression.

Footprint-Free Human Induced Pluripotent Stem Cells From Articular Cartilage With Redifferentiation Capacity: A First Step Toward a Clinical-Grade Cell Source

Human induced pluripotent stem cells (iPSCs) are potential cell sources for regenerative medicine; however, clinical applications of iPSCs are restricted because of undesired genomic modifications associated with most reprogramming protocols. We show, for the first time, that chondrocytes from autologous chondrocyte implantation (ACI) donors can be efficiently reprogrammed into iPSCs using a nonintegrating method based on mRNA delivery, resulting in footprint-free iPSCs (no genome-sequence modifications), devoid of viral factors or remaining reprogramming molecules. The search for universal allogeneic cell sources for the ACI regenerative treatment has been difficult because making chondrocytes with high matrix-forming capacity from pluripotent human embryonic stem cells has proven challenging and human mesenchymal stem cells have a predisposition to form hypertrophic cartilage and bone. We show that chondrocyte-derived iPSCs can be redifferentiated in vitro into cartilage matrix-producing cells better than fibroblast-derived iPSCs and on par with the donor chondrocytes, suggesting the existence of a differentiation bias toward the somatic cell origin and making chondrocyte-derived iPSCs a promising candidate universal cell source for ACI. Whole-genome single nucleotide polymorphism array and karyotyping were used to verify the genomic integrity and stability of the established iPSC lines. Our results suggest that RNA-based technology eliminates the risk of genomic integrations or aberrations, an important step toward a clinical-grade cell source for regenerative medicine such as treatment of cartilage defects and osteoarthritis.

Whole-Genome Single Nucleotide Polymorphism Array Analysis Is Complementary to Classical Cytogenetic Analysis in the Evaluation of Lymphoid Proliferations

To explore how much additional information single nucleotide polymorphism (SNP) arrays provide and whether they could partially replace classical cytogenetics. Twenty-six lymphoid proliferations with available cytogenetic studies were analyzed with the Affymetrix Genome-Wide Human SNP Array 6.0 (Affymetrix, Santa Clara, CA). Eleven of 26 cases demonstrated complete concordance between cytogenetics and SNP analysis, and 10 of 26 cases demonstrated partial concordance. Five discordant cases had copy number abnormalities (CNAs) with cytogenetics not identified with SNP arrays. While SNP analysis showed CNAs not apparent by cytogenetics in eight cases and helped clarify the karyotype in six cases, cytogenetics demonstrated CNAs not seen by SNP analysis in 15 cases as well as balanced translocations in 12 cases. The combination of cytogenetics and SNP analysis results in a higher overall yield in identifying numerical chromosomal abnormalities than either technique alone.

Implementation of high‐resolution SNP arrays in the investigation of fetuses with ultrasound malformations: 5 years of clinical experience

Chromosome microarray analysis (CMA) has proven to be a powerful tool in postnatal patients with intellectual disabilities, and it is increasingly used in prenatal diagnosis. However, its diagnostic capabilities in prenatal diagnosis vary, and clinical experiences have failed to establish a consensus regarding CMA indications, the design and resolution of microarrays, and the notification and interpretation of copy number variations (CNVs). We present our 5 years of clinical experience using whole-genome high-resolution single nucleotide polymorphism (SNP) arrays to investigate 446 fetuses that had structural malformations detected with ultrasound but for which standard karyotyping analysis showed normal karyotypes. CMA revealed genomic CNVs in 323 (72.4%) cases and clinically significant CNVs in 11.4% of the fetuses (51/446), including 2 cases of uniparental disomy (UPD) as well as 1 case of cryptic mosaic monosomy of chromosome X. Variants of unknown significance (VOUS) existed in 2.0% of the tested fetuses (9/446). Our results demonstrate the value of whole-genome high-resolution SNP arrays in fetuses with congenital malformations and give a higher detection rate of clinically significant genomic imbalance, especially for detecting UPD. Sufficient communication between technicians and genetic counselors, along with parental testing and comparison with data from in-house or international sources, can significantly reduce VOUS.

Additional Genomic Aberrations Identified by Single Nucleotide Polymorphism Array-Based Karyotyping in an Acute Myeloid Leukemia Case with Isolated del(20q) Abnormality

Prognosis is known to be better in cases with isolated chromosomal abnormalities than in those with complex karyotypes. Accordingly, del(20q) as an isolated abnormality must be distinguished from cases in which it is associated with other chromosomal rearrangements for a better stratification of prognosis. We report a case of an isolated del(20q) abnormality with additional genomic aberrations identified using whole-genome single nucleotide polymorphism array (SNP-A)-based karyotyping. A 39-yr-old man was diagnosed with AML without maturation. Metaphase cytogenetic analysis (MC) revealed del(20)(q11.2) as the isolated abnormality in 100% of metaphase cells analyzed, and FISH analysis using D20S108 confirmed the 20q deletion in 99% of interphase cells. Using FISH, other rearrangements such as BCR/ABL1, RUNX1/RUNX1T1, PML/RARA, CBFB/MYH11, and MLL were found to be negative. SNP-A identified an additional copy neutral loss of heterozygosity (CN-LOH) in the 11q13.1-q25 region. Furthermore, SNP-A allowed for a more precise definition of the breakpoints of the 20q deletion (20q11.22-q13.31). Unexpectedly, the terminal regions showed gain on chromosome 20q. The patient did not achieve complete remission; 8 months later, he died from complications of leukemic cell infiltrations into the central nervous system. This study suggests that a presumably isolated chromosomal abnormality by MC may have additional genomic aberrations, including CN-LOH, which could be associated with a poor prognosis. SNP-A-based karyotyping may be helpful for distinguishing true isolated cases from cases in combination with additional genomic aberrations not detected by MC.

Ring Chromosome 5 in Acute Myeloid Leukemia Defined by Whole-genome Single Nucleotide Polymorphism Array

Chromosomes forming a corresponding ring cannot be clearly defined by conventional cytogenetics or FISH. Karyotypic analyses using whole-genome single nucleotide polymorphism arrays (SNP-A) may result in the identification of previously cryptic lesions and allow for more precise definition of breakpoints. We describe a case of AML with metaphase cells bearing -5, del(11)(q22), and +r. With SNP-A, a 5p-terminal deletion (11 megabases [Mb]), a 5q-terminal deletion (27 Mb), an 11q-interstitial deletion (29 Mb), and a 21q gain (3 Mb) were identified. Therefore, the G-banded karyotype was revised as 46, XY, r(5)(p15. 2q33.2), del(11)(q14.1q23.2), dup(21)(q22.13q22.2)[18]/46,XY[2]. SNP-A could be a powerful tool for characterizing ring chromosomes in which the involved chromosomes or bands cannot be precisely identified by conventional cytogenetics or FISH.

Integrative analysis of array-comparative genomic hybridisation and matched gene expression profiling data reveals novel genes with prognostic significance in oesophageal adenocarcinoma

Background and aimsThe incidence of oesophageal adenocarcinoma (OAC) has been increasing rapidly with a dismal survival rate of less than 20%. Understanding the genomic aberrations and biology of this cancer...

Histopathologic subtype-specific genomic profiles of renal cell carcinomas identified by high-resolution whole-genome single nucleotide polymorphism array analysis

To elucidate the novel and common genetic changes in histopathologic subtype-specific profiles of renal cell carcinomas (RCCs), a newly developed high-resolution whole-genome array analysis was applied. Human CNV370-Duo DNA Analysis BeadChip (genotype 370K) was used in a panel of 22 primary clear cell RCCs (ccRCCs), seven papillary RCCs (PRCCs) (six type II and one type I) and eight chromophobe RCCs (ChRCCs). In ccRCC, a chromosome 3p loss was identified in 95% of the carcinomas, suggesting that 3p loss is the first stage in ccRCC carcinogenesis. Other frequent changes included losses of 1p (23%), 3q (46%) and 8p (32%), and gains of 5q (32%), 7p (27%), 7q (27%) and 1q (23%). The most frequent chromosomal losses in PRCC (43%) were noted in 3p and 3q, followed by 29% of losses of 1p, 1q, 11q, 18q, 22p and 22q, and gains of 20q (57%), 20p (43%), 8q (43%) and 12q (43%). Loss of the entire chromosomes 1, 2, 6, 8, 10, 13 or 17 was noted in patients with ChRCC. A high-density single nucleotide polymorphism array analysis confirmed that partial chromosomal changes rarely occur in ChRCC. Additionally, 32 microdeletions and 10 microamplifications of less than 1 Mb were detected, which may represent potential candidate tumor suppressor genes and oncogenes, respectively.

Investigating psychosis candidate genes in Alzheimer's disease with psychosis using genome-wide association studies

As Alzheimer's disease (AD) progresses many sufferers experience additional behavioural and psychological symptoms such as psychosis. Psychotic symptoms are reported to affect 40-60% of individuals with AD and are associated with more rapid cognitive and functional decline, more severe cognitive impairment, premature institutionalization, and increased risks for agitated and aggressive behaviour. Several studies demonstrate excess aggregation of psychosis in families, suggesting that psychosis in Alzheimer disease (AD+P) represents a distinct subtype that is, in part, genetically determined. Recent studies in schizophrenia, bipolar affective disorder (BPAD) and AD+P suggest that psychosis susceptibility or modifier genes may act across the “disease divide”. Our study investigates susceptibility genes for psychosis related disorders identified through genome-wide association (GWA) studies, in our large GWA study of AD which includes 1,971 cases stratified for the presence or absence of psychotic symptoms. Psychosis candidate genes were chosen for investigation on the basis that at least one polymorphism within the gene (or within the flanking regions) had been identified as showing significant association to a psychosis related disorder in a published GWA study. These genes/markers were compared to data produced from analysis of our AD GWA study data using presence/absence of psychotic symptoms as a categorical variable. Our GWA study is a large resource containing 4,047 AD cases and 8,863 controls. All AD cases met criteria for either probable (NINCDS-AARDA, DSM-IV) or definite (CERAD) AD. Elderly controls were aged 60 years or over and were screened for cognitive decline or neuropathological signs of AD. Population controls were drawn from large existing cohorts with available GWA study data. 4572 samples were genotyped at the Sanger Institute on the Illumina 610-quad chip. The remaining samples were genotyped using either the Illumina 317k or 550k whole-genome single-nucleotide polymorphism arrays. Results of the study will be presented at ICAD 2009. Previous evidence suggests that psychosis susceptibility or modifier genes may act across the traditional “disease divide”. Identification of genetic variation associated with psychosis in AD will further our understanding of the disease mechanisms which underlie this sub-type of AD and may have implications for other neurodegenerative disorders where psychotic symptoms are common.

Chondroid Cystic Malformation of the Lung With Trisomy 8 Mosaicism: A New Cystic Lung Malformation

Neonatal cystic disorders of the lungs are a heterogeneous malformative group including giant lobar hyperinflation, congenital pulmonary airway malformations, intralobar pulmonary sequestration, and bronchogenic cyst. Here, we describe a giant cystic pulmonary malformation in a 5-year-old girl, morphologically characterized by a highly disorganized proliferation of numerous cartilage islands, abundant mesenchymal tissue with abundant adipose differentiation, and epithelium-lined cysts. Cytogenetic analysis revealed an isolated trisomy 8, as the sole karyotype anomaly, a finding further confirmed by a whole-genome single nucleotide polymorphism array genotyping. The trisomy 8 was observed by fluorescent in situ hybridization within the malformation, and also in adjacent pulmonary parenchyma. A search of the literature revealed only 2 cases having similarities with the present case, but bearing different names. We believe that this lesion differs from congenital pulmonary airway malformations and from adult-type pulmonary hamartomas. We propose for this malformative mass the name "chondroid cystic malformation of the lung."

Genome-Wide Copy Number Analysis in Esophageal Adenocarcinoma Using High-Density Single-Nucleotide Polymorphism Arrays

We applied whole-genome single-nucleotide polymorphism arrays to define a comprehensive genetic profile of 23 esophageal adenocarcinoma (EAC) primary tumor biopsies based on loss of heterozygosity (LOH) and DNA copy number changes. Alterations were common, averaging 97 (range, 23-208) per tumor. LOH and gains averaged 33 (range, 3-83) and 31 (range, 11-73) per tumor, respectively. Copy neutral LOH events averaged 27 (range, 7-57) per EAC. We noted 126 homozygous deletions (HD) across the EAC panel (range, 0-11 in individual tumors). Frequent HDs within FHIT (17 of 23), WWOX (8 of 23), and DMD (6 of 23) suggest a role for common fragile sites or genomic instability in EAC etiology. HDs were also noted for known tumor suppressor genes (TSG), including CDKN2A, CDKN2B, SMAD4, and GALR1, and identified PDE4D and MGC48628 as potentially novel TSGs. All tumors showed LOH for most of chromosome 17p, suggesting that TSGs other than TP53 may be targeted. Frequent gains were noted around MYC (13 of 23), BCL9 (12 of 23), CTAGE1 (14 of 23), and ZNF217 (12 of 23). Thus, we have confirmed previous reports indicating frequent changes to FHIT, CDKN2A, TP53, and MYC in EAC and identified additional genes of interest. Meta-analysis of previous genome-wide EAC studies together with the data presented here highlighted consistent regions of gain on 8q, 18q, and 20q and multiple LOH regions on 4q, 5q, 17p, and 18q, suggesting that more than one gene may be targeted on each of these chromosome arms. The focal gains and deletions documented here are a step toward identifying the key genes involved in EAC development.

Genome-Wide Loss of Heterozygosity and Copy Number Analysis in Melanoma Using High-Density Single-Nucleotide Polymorphism Arrays

Although a number of genes related to melanoma development have been identified through candidate gene screening approaches, few studies have attempted to conduct such analyses on a genome-wide scale. Here we use Illumina 317K whole-genome single-nucleotide polymorphism arrays to define a comprehensive allelotype of melanoma based on loss of heterozygosity (LOH) and copy number changes in a panel of 76 melanoma cell lines. In keeping with previous reports, we found frequent LOH on chromosome arms 9p (72%), 10p (55%), 10q (55%), 9q (49%), 6q (43%), 11q (43%), and 17p (41%). Tumor suppressor genes (TSGs) can be identified through homozygous deletion (HD). We detected 174 HDs, the most common of which targeted CDKN2A (n = 33). The second highest frequency of HD occurred in PTEN (n = 8), another well known melanoma TSG. HDs were also common for PTPRD (n = 7) and HDAC4 (n = 3), TSGs recently found to be mutated or deleted in other cancer types. Analysis of other HDs and regions of LOH that we have identified might lead to the characterization of further melanoma TSGs. We noted 197 regional amplifications, including some centered on the melanoma oncogenes MITF (n = 9), NRAS (n = 3), BRAF (n = 3), and CCND1 (n = 3). Other amplifications potentially target novel oncogenes important in the development of a subset of melanomas. The numerous focal amplifications and HDs we have documented here are the first step toward identifying a comprehensive catalog of genes involved in melanoma development, some of which may be useful prognostic markers or targets for therapies to treat this disease.