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Therapy-related myeloid neoplasm (t-MN) in the pediatric population is not well characterized. We studied 12 pediatric patients diagnosed with t-MN in our institution since 2006. The median age at the t-MN diagnoses was 14.8 years (range, 9 to 20 y). The primary malignancies included 9 solid tumors and 3 hematopoietic malignancies. Rhabdomyosarcoma (n=4) was the most common primary malignancy. Five of the 9 patients with solid tumors and all 3 patients with hematopoietic malignancies had primary neoplasms involving bone marrow. The median latency period was 5.2 years (range, 1.8 to 13.8 y). Thrombocytopenia was present in all patients at the t-MN diagnoses. Complete or partial monosomy of chromosome 5 or 7 were the 2 most common cytogenetic abnormalities. A quarter of patients demonstrated a genetic predisposition to t-MN: 1 with Li-Fraumeni syndrome with a germline TP53R248Q mutation, 1 with Noonan syndrome with a somatic mutation (PTPN11S502T), and 1 with a constitutive chromosomal translocation [t(X;9)(p22;q34)] and a germline TP53L130V mutation. Outcomes remain poor. Two patients survived 3 and 5.1 years after hematopoietic stem cell transplantation.

Chromosomal microarray technologies, including array comparative genomic hybridization and single-nucleotide polymorphism array, are widely applied in the diagnostic evaluation for both constitutional and neoplastic disorders. In a constitutional setting, this technology is accepted as the first-tier test for the evaluation of chromosomal imbalances associated with intellectual disability, autism, and/or multiple congenital anomalies. Furthermore, chromosomal microarray analysis is recommended for patients undergoing invasive prenatal diagnosis with one or more major fetal structural abnormalities identified by ultrasonographic examination, and in the evaluation of intrauterine fetal demise or stillbirth when further cytogenetic analysis is desired. This technology also provides important genomic data in the diagnosis, prognosis, and therapy of neoplastic disorders, including both hematologic malignancies and solid tumors. To assist clinical laboratories in the validation of chromosomal microarray methodologies for constitutional and neoplastic applications, the American College of Medical Genetics and Genomics (ACMG) Laboratory Quality Assurance Committee has developed these updated technical laboratory standards, which replace the ACMG technical standards and guidelines for microarray analysis in constitutional and neoplastic disorders previously published in 2013.

Cytogenomic analyses of acquired clonal chromosomal abnormalities in neoplastic blood, bone marrow, and/or lymph nodes are instrumental in the clinical management of patients with hematologic neoplasms. Cytogenetic analyses assist in the diagnosis of such disorders and can provide important prognostic information. Furthermore, cytogenetic studies can provide crucial information regarding specific genetically defined subtypes of these neoplasms that may have targeted therapies. At time of relapse, cytogenetic analysis can confirm recurrence of the original neoplasm, detect clonal disease evolution, or uncover a new unrelated neoplastic process. This section deals specifically with the technical standards applicable to cytogenomic studies of acquired clonal chromosomal abnormalities in neoplastic blood, bone marrow, and/or lymph nodes. This updated Section E6.1-6.6 supersedes the previous Section E6 in Section E: Clinical Cytogenetics of the American College of Medical Genetics and Genomics Technical Standards for Clinical Genetics Laboratories.

Patients with high-risk acute promyelocytic leukemia (APL) have inferior outcomes compared with patients with low-risk APL, predominantly due to higher risk of early mortality related to hemorrhage. The majority of regimens contain prolonged maintenance, but the impact of this phase is not clear in the era of all trans retinoic acid (ATRA) and arsenic trioxide (ATO). We present a retrospective analysis of 10 patients that were treated for high risk APL based on the consolidation treatment phase of APL 0406 study without subsequent maintenance. With a median follow up of 38 months, all patients remain in remission.

The detection of acquired copy-number abnormalities (CNAs) and copy-neutral loss of heterozygosity (CN-LOH) in neoplastic disorders by chromosomal microarray analysis (CMA) has significantly increased over the past few years with respect to both the number of laboratories utilizing this technology and the broader number of tumor types being assayed. This highlights the importance of standardizing the interpretation and reporting of acquired variants among laboratories. To address this need, a clinical laboratory-focused workgroup was established to draft recommendations for the interpretation and reporting of acquired CNAs and CN-LOH in neoplastic disorders. This project is a collaboration between the American College of Medical Genetics and Genomics (ACMG) and the Cancer Genomics Consortium (CGC). The recommendations put forth by the workgroup are based on literature review, empirical data, and expert consensus of the workgroup members. A four-tier evidence-based categorization system for acquired CNAs and CN-LOH was developed, which is based on the level of available evidence regarding their diagnostic, prognostic, and therapeutic relevance: tier 1, variants with strong clinical significance; tier 2, variants with some clinical significance; tier 3, clonal variants with no documented neoplastic disease association; and tier 4, benign or likely benign variants. These recommendations also provide a list of standardized definitions of terms used in the reporting of CMA findings, as well as a framework for the clinical reporting of acquired CNAs and CN-LOH, and recommendations for how to deal with suspected clinically significant germline variants.

Purpose:The 2010 consensus statement on diagnostic chromosomal microarray (CMA) testing recommended an array resolution ≥400 kb throughout the genome as a balance of analytical and clinical sensitivity. In spite of the clear evidence for pathogenicity of large copy-number variants (CNVs) in neurodevelopmental disorders and/or congenital anomalies, the significance of small, nonrecurrent CNVs (<500 kb) has not been well established in a clinical setting.Methods:We investigated the clinical significance of all nonpolymorphic small, nonrecurrent CNVs (<500 kb) in patients referred for CMA clinical testing over a period of 6 years, from 2009 to 2014 (a total of 4,417 patients). We excluded from our study patients with benign or likely benign CNVs and patients with only recurrent microdeletions/microduplications <500 kb.Results:In total, 383 patients (8.67%) were found to carry at least one small, nonrecurrent CNV, of whom 176 patients (3.98%) had one small CNV classified as a variant of uncertain significance (VUS), 45 (1.02%) had two or more small VUS CNVs, 20 (0.45%) had one small VUS CNV and a recurrent CNV, 113 (2.56%) had one small pathogenic or likely pathogenic CNV, 17 (0.38%) had two or more small pathogenic or likely pathogenic CNVs, and 12 (0.27%) had one small pathogenic or likely pathogenic CNV and a recurrent CNV. Within the pathogenic group, 80 of 142 patients (56% of all small pathogenic CNV cases) were found to have a single whole-gene or exonic deletion. The themes that emerged from our study are presented in the Discussion section.Conclusions:Our study demonstrates the diagnostic clinical relevance of small, nonrecurrent CNVs <500 kb during CMA clinical testing and underscores the need for careful clinical interpretation of these CNVs.Genet Med 19 4, 377–385.

The 2010 consensus statement on diagnostic chromosomal microarray (CMA) testing recommended an array resolution ≥400 kb throughout the genome as a balance of analytical and clinical sensitivity. In spite of the clear evidence for pathogenicity of large copy-number variants (CNVs) in neurodevelopmental disorders and/or congenital anomalies, the significance of small, nonrecurrent CNVs (<500 kb) has not been well established in a clinical setting.

Tyrosine kinase inhibitor (TKI) treatment of chronic myeloid leukemia (CML) has limited efficacy against leukemia stem cells (LSC) responsible for disease propagation, and most CML patients require continued TKI treatment to maintain remission. LSC maintenance is related, at least in part, to signals from the bone marrow microenvironment (BMM). Our previous studies have shown that Wnt signaling from the BMM contributes to preservation of CML LSC following TKI treatment. Secretion of Wnt ligands requires their modification by the O-acyl transferase Porcupine (PORCN). Here we investigated the activity of a potent and selective PORCN inhibitor, WNT974, against CML stem and progenitor cells. WNT974 efficiently antagonized Wnt signaling in human CML CD34+ cells, and in combination with the TKI nilotinib (NIL) significantly enhanced inhibition of proliferation and colony-forming potential of CML stem and progenitor cells and reduced their growth in immunodeficient mice in vivo, in comparison with NIL alone. Treatment of transgenic CML mice in vivo with NIL in combination with WNT974 significantly reduced leukemic stem and progenitor cell numbers, reduced regeneration of leukemic long-term hematopoietic stem cells in secondary transplant recipients, and enhanced survival of mice after discontinuation of treatment, in comparison with NIL alone. CML progenitors demonstrated enhanced sensitivity to Wnt stimulation, associated with increased expression of the FZD4 receptor. FZD4 knockdown inhibited CML progenitor growth. These results support further investigation of PORCN targeting to inhibit Wnt secretion and signaling and enhance targeting of CML stem cells while sparing their normal counterparts.

Tyrosine kinase inhibitor (TKI) treatment of chronic myeloid leukemia (CML) has limited efficacy against leukemia stem cells (LSC) responsible for disease propagation, and most CML patients require continued TKI treatment to maintain remission. LSC maintenance is related, at least in part, to signals from the bone marrow microenvironment (BMM). Our previous studies have shown that Wnt signaling from the BMM contributes to preservation of CML LSC following TKI treatment. Secretion of Wnt ligands requires their modification by the O-acyl transferase Porcupine (PORCN). Here we investigated the activity of a potent and selective PORCN inhibitor, WNT974, against CML stem and progenitor cells. WNT974 efficiently antagonized Wnt signaling in human CML CD34+cells, and in combination with the TKI nilotinib (NIL) significantly enhanced inhibition of proliferation and colony-forming potential of CML stem and progenitor cells and reduced their growth in immunodeficient mice in vivo, in comparison with NIL alone. Treatment of transgenic CML mice in vivo with NIL in combination with WNT974 significantly reduced leukemic stem and progenitor cell numbers, reduced regeneration of leukemic long-term hematopoietic stem cells in secondary transplant recipients, and enhanced survival of mice after discontinuation of treatment, in comparison with NIL alone. CML progenitors demonstrated enhanced sensitivity to Wnt stimulation, associated with increased expression of the FZD4 receptor. FZD4 knockdown inhibited CML progenitor growth. These results support further investigation of PORCN targeting to inhibit Wnt secretion and signaling and enhance targeting of CML stem cells while sparing their normal counterparts.

Multiple studies suggest an association between DLG2and neurodevelopmental disorders and indicate the haploinsufficiency of this gene; however, few cases have been thoroughly described. We performed additional studies to confirm this clinical association and DLG2haploinsufficiency.

Disclaimer: These ACMG standards and guidelines are developed primarily as an educational resource for clinical laboratory geneticists to help them provide quality clinical laboratory genetic services. Adherence to these standards and guidelines is voluntary and does not necessarily ensure a successful medical outcome. These standards and guidelines should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same results. In determining the propriety of any specific procedure or test, the clinical laboratory geneticist should apply his or her own professional judgment to the specific circumstances presented by the individual patient or specimen. Clinical laboratory geneticists are encouraged to document in the patient’s record the rationale for the use of a particular procedure or test, whether or not it is in conformance with these standards and guidelines. They also are advised to take notice of the date any particular guideline was adopted, and to consider other relevant medical and scientific information that becomes available after that date. It also would be prudent to consider whether intellectual property interests may restrict the performance of certain tests and other procedures.Cytogenetic analysis of tumor tissue is performed to detect and characterize chromosomal aberrations to aid histopathological and clinical diagnosis and patient management. At the time of diagnosis, known recurrent clonal aberrations may facilitate histopathological diagnosis and subtyping of the tumor. This information may contribute to clinical therapeutic decisions. However, even when tumors have a known recurrent clonal aberration, each tumor is genetically unique and probably heterogeneous. It is important to discover as much about the genetics of a tumor at diagnosis as is possible with the methods available for study of the tumor material. The information gathered at initial study will inform follow-up studies, whether for residual disease detection, determination of relapse and clonal evolution, or identifying a new disease clone.This updated Section E6.5–6.8 has been incorporated into and supersedes the previous Sections E6.4 and E6.5 in Section E: Clinical Cytogenetics of the 2009 Edition (Revised 01/2010), American College of Medical Genetics and Genomics Standards and Guidelines for Clinical Genetics Laboratories. This section deals specifically with the standards and guidelines applicable to lymph node and solid tumor chromosome analysis.Genet Med 18 6, 643–648.

Disclaimer: These American College of Medical Genetics and Genomics standards and guidelines are developed primarily as an educational resource for clinical laboratory geneticists to help them provide quality clinical laboratory genetic services. Adherence to these standards and guidelines is voluntary and does not necessarily ensure a successful medical outcome. These standards and guidelines should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same results. In determining the propriety of any specific procedure or test, the clinical laboratory geneticist should apply his or her own professional judgment to the specific circumstances presented by the individual patient or specimen. Clinical laboratory geneticists are encouraged to document in the patient’s record the rationale for the use of a particular procedure or test, whether or not it is in conformance with these standards and guidelines. They also are advised to take notice of the date any particular guideline was adopted, and to consider other relevant medical and scientific information that becomes available after that date. It also would be prudent to consider whether intellectual property interests may restrict the performance of certain tests and other procedures.Cytogenetic analyses of hematological neoplasms are performed to detect and characterize clonal chromosomal abnormalities that have important diagnostic, prognostic, and therapeutic implications. At the time of diagnosis, cytogenetic abnormalities assist in the diagnosis of such disorders and can provide important prognostic information. At the time of relapse, cytogenetic analysis can be used to confirm recurrence of the original neoplasm, detect clonal disease evolution, or uncover a new unrelated neoplastic process. This section deals specifically with the standards and guidelines applicable to chromosome studies of neoplastic blood and bone marrow–acquired chromosomal abnormalities. This updated Section E6.1–6.4 has been incorporated into and supersedes the previous Section E6 in Section E: Clinical Cytogenetics of the 2009 Edition (Revised 01/2010), American College of Medical Genetics and Genomics Standards and Guidelines for Clinical Genetics Laboratories.Genet Med 18 6, 635–642.

Disclaimer:These American College of Medical Genetics and Genomics standards and guidelines are developed primarily as an educational resource for clinical laboratory geneticists to help them provide quality clinical laboratory genetic services. Adherence to these standards and guidelines is voluntary and does not necessarily ensure a successful medical outcome. These standards and guidelines should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same results. In determining the propriety of any specific procedure or test, the clinical laboratory geneticist should apply his or her own professional judgment to the specific circumstances presented by the individual patient or specimen. Clinical laboratory geneticists are encouraged to document in the patient’s record the rationale for the use of a particular procedure or test, whether or not it is in conformance with these standards and guidelines. They also are advised to take notice of the date any particular guideline was adopted, and to consider other relevant medical and scientific information that becomes available after that date. It also would be prudent to consider whether intellectual property interests may restrict the performance of certain tests and other procedures.

Disclaimer:These ACMG standards and guidelines are developed primarily as an educational resource for clinical laboratory geneticists to help them provide quality clinical laboratory genetic services. Adherence to these standards and guidelines is voluntary and does not necessarily ensure a successful medical outcome. These standards and guidelines should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same results. In determining the propriety of any specific procedure or test, the clinical laboratory geneticist should apply his or her own professional judgment to the specific circumstances presented by the individual patient or specimen. Clinical laboratory geneticists are encouraged to document in the patient’s record the rationale for the use of a particular procedure or test, whether or not it is in conformance with these standards and guidelines. They also are advised to take notice of the date any particular guideline was adopted, and to consider other relevant medical and scientific information that becomes available after that date. It also would be prudent to consider whether intellectual property interests may restrict the performance of certain tests and other procedures.

Objectives Cleft lip and/or cleft palate (CL/P) occurs either as an isolated anomaly or as one manifestation of genetic syndromes. Chromosomal abnormalities from karyotype analysis are commonly seen in cases of nonisolated CL/P. This study was designed to evaluate the usefulness of clinical array comparative genomic hybridization (aCGH) testing in patients with CL/P. Our objectives were to identify the clinical phenotypes that are predicative of an abnormal aCGH result, correlate aCGH results with language outcome, and analyze the data in the abnormal aCGH results group.Methods Nonisolated CL/P patients who had clinical aCGH testing performed between 2009 and 2012 in the University of Alabama at Birmingham cytogenetics lab were enrolled. The demographic data, clinical phenotypes, and speech outcome were collected.Results Two hundred forty-five nonisolated CL/P patients were studied, with 62 having an abnormal aCGH result compared to 183 patients with a normal aCGH result. The presence of developmental delay/intellectual disability (DD/ID), dysmorphic features, congenital anomalies, and/or family history of DD/ID were significantly higher in the abnormal aCGH group (P< .05). Neither the aCGH results nor the type of CL/P correlated with speech outcome. Finally, analysis of the abnormal aCGH result group revealed that DD/ID had a strong positive association with the copy number variation pathogenicity and the number of genes involved.Conclusions This study demonstrated the diagnostic value of clinical aCGH testing in CL/P patients who present with DD/ID, dysmorphic features, other congenital anomalies, and/or family history of DD/ID.

AbstractBackground:CHD is the leading cause of mortality due to birth defects. Array comparative genomic hybridisation (aCGH) detects submicroscopic copy number changes and may improve identification of the genetic basis of CHD. Methods:This is a retrospective analysis of 1252 patients from a regional referral centre who had undergone aCGH. Of the patients, 173 had CHD. A whole-genome custom-designed oligonucleotide array with >44,000 probes was used to detect copy number changes. Results:Of the 1252 patients, 335 (26.76%) had abnormal aCGH results. Of the 173 patients with CHD, 50 (28.9%) had abnormal aCGH results versus 284 (26.3%) of 1079 non-cardiac patients. There were six patients with CHD who had well-described syndromes such as Wolf–Hirschhorn, trisomy 13, DiGeorge, and Williams. Of the patients with CHD, those with left-sided heart disease had the highest proportion (14/31; 45.13%) of abnormal aCGH results, followed by those with conotruncal heart disease (10/29; 34.48%), endocardial cushion defects (13/50; 26%), complex/other heart disease (12/52; 23.08%), and patent ductus arteriosus (1/11; 9.09%). Conclusions:Patients with CHD are at a substantial risk of having microdeletions and microduplications. The incidence of abnormalities on aCGH analysis is higher than identified with karyotype, and identification of copy number changes may help identify the genetic basis of the specific heart defects. However, aCGH may not have a significant diagnostic yield in those with isolated CHD. Further research using larger data sets may help identify candidate genes associated with CHD.

Recent studies clearly demonstrate that copy number variations (CNVs) are widespread in our genome and play an important role in human genetic variation, accounting for both human population diversity and human genetic disease. This review will discuss the most current knowledge regarding our understanding of the biology of CNVs in relation to human genetic disease.

Purpose:The five segmental duplications (LCR22-D to -H) at the distal region of chromosome 22 band q11.2 in the region immediately distal to the DiGeorge/velocardiofacial syndrome deleted region have been implicated in the recurrent distal 22q11.2 microdeletions. To date, the distal 22q11.2 microdeletions have been grouped together as a single clinical entity despite the fact that these deletions are variable in size and position depending on the mediating LCR22s.Methods:Here, we report 13 new unrelated patients with variable size deletions in the distal 22q11.2 region as shown by cytogenomic array analyses. We compare our patients’ clinical features with those of previously reported cases to better dissect the phenotypic correlations based on the deletion size and position.Results:Six patients had the 1.1-Mb deletion flanked by LCR22-D and -E, and presented clinically with a phenotype consistent with previously reported cases with distal 22q11.2 microdeletions. Three patients had the 1.8-Mb deletion flanked by LCR22-D and -F, and presented with a similar phenotype. Four patients had the 700-kb deletion flanked by LCR22-E and -F, and presented with a milder phenotype that lacked growth restriction and cardiovascular defects.Conclusion:We suggest that the recurrent distal 22q11.2 microdeletions do not represent a single clinical entity, and propose categorizing these deletions into three types according to their genomic position. All three deletion types are thought to be pathogenic and are most often de novo. They all share some presenting features but also have their unique features and risks.Genet Med 16 1, 92–100.

Patients with neurofibromatosis type 1 (NF1) develop benign plexiform neurofibromas that frequently progress to become malignant peripheral nerve sheath tumors (MPNSTs). A genetically engineered mouse model that accurately models plexiform neurofibroma–MPNST progression in humans would facilitate identification of somatic mutations driving this process. We previously reported that transgenic mice overexpressing the growth factor neuregulin-1 in Schwann cells (P0-GGFβ3 mice) develop MPNSTs. To determine whether P0-GGFβ3 mice accurately model human neurofibroma–MPNST progression, cohorts of these animals were monitored through death and were necropsied; 94% developed multiple neurofibromas, with 70% carrying smaller numbers of MPNSTs. Nascent MPNSTs were identified within neurofibromas, suggesting that these sarcomas arise from neurofibromas. Although neurofibromin expression was maintained, P0-GGFβ3 MPNSTs exhibited Ras hyperactivation, as in human NF1-associated MPNSTs. P0-GGFβ3 MPNSTs also exhibited abnormalities in the p16INK4A–cyclin D/CDK4–Rb and p19ARF–Mdm–p53 pathways, analogous to their human counterparts. Array comparative genomic hybridization (CGH) demonstrated reproducible chromosomal alterations in P0-GGFβ3 MPNST cells (including universal chromosome 11 gains) and focal gains and losses affecting 39 neoplasia-associated genes (including Pten, Tpd52, Myc, Gli1, Xiap, and Bbc3/PUMA). Array comparative genomic hybridization also identified recurrent focal copy number variations affecting genes not previously linked to neurofibroma or MPNST pathogenesis. We conclude that P0-GGFβ3 mice represent a robust model of neurofibroma-MPNST progression useful for identifying novel genes driving neurofibroma and MPNST pathogenesis.

Gene expression profiling of 207 uniformly treated children with high-risk B-progenitor acute lymphoblastic leukemia revealed 29 of 207 cases (14%) with markedly elevated expression of CRLF2 (cytokine receptor-like factor 2). Each of the 29 cases harbored a genomic rearrangement of CRLF2: 18 of 29 (62%) had a translocation of the immunoglobulin heavy chain gene IGH@ on 14q32 to CRLF2 in the pseudoautosomal region 1 of Xp22.3/Yp11.3, whereas 10 (34%) cases had a 320-kb interstitial deletion centromeric of CRLF2, resulting in a P2RY8-CRLF2 fusion. One case had both IGH@-CRLF2 and P2RY8-CRLF2, and another had a novel CRLF2 rearrangement. Only 2 of 29 cases were Down syndrome. CRLF2 rearrangements were significantly associated with activating mutations of JAK1 or JAK2, deletion or mutation of IKZF1, and Hispanic/Latino ethnicity (Fisher exact test, P < .001 for each). Within this cohort, patients with CRLF2 rearrangements had extremely poor treatment outcomes compared with those without CRLF2 rearrangements (35.3% vs 71.3% relapse-free survival at 4 years; P < .001). Together, these observations suggest that activation of CRLF2 expression, mutation of JAK kinases, and alterations of IKZF1 cooperate to promote B-cell leukemogenesis and identify these pathways as important therapeutic targets in this disease. This trial was registered at www.clinicaltrials.gov as #NCT00005603.

Gene expression profiling of 207 uniformly treated children with high-risk B-progenitor acute lymphoblastic leukemia revealed 29 of 207 cases (14%) with markedly elevated expression of CRLF2(cytokine receptor-like factor 2). Each of the 29 cases harbored a genomic rearrangement of CRLF2: 18 of 29 (62%) had a translocation of the immunoglobulin heavy chain gene IGH@ on 14q32 to CRLF2in the pseudoautosomal region 1 of Xp22.3/Yp11.3, whereas 10 (34%) cases had a 320-kb interstitial deletion centromeric of CRLF2, resulting in a P2RY8-CRLF2fusion. One case had both IGH@-CRLF2and P2RY8-CRLF2, and another had a novel CRLF2rearrangement. Only 2 of 29 cases were Down syndrome. CRLF2rearrangements were significantly associated with activating mutations of JAK1or JAK2, deletion or mutation of IKZF1, and Hispanic/Latino ethnicity (Fisher exact test, P< .001 for each). Within this cohort, patients with CRLF2rearrangements had extremely poor treatment outcomes compared with those without CRLF2rearrangements (35.3% vs 71.3% relapse-free survival at 4 years; P< .001). Together, these observations suggest that activation of CRLF2expression, mutation of JAKkinases, and alterations of IKZF1cooperate to promote B-cell leukemogenesis and identify these pathways as important therapeutic targets in this disease. This trial was registered at www.clinicaltrials.govas #NCT00005603.

Here, we report two cases with isolated distal 11q rearrangement and multiple congenital anomalies. The first patient is a twoandahalf year old male referred to our genetics clinic due to dysmorphic features and developmental delay including speech delay. Using conventional and molecular cytogenetic techniques, we demonstrate that he carries a recombinant chromosome with duplication of the 11q23.3q24.2 region resulting from an intrachromosomal insertion in the father. The second patient was originally reported by PartidaPerez, et al. PartidaPerez et al., 2006 as having a tandem duplication of the 11q23.3 region. We performed array comparative genomic hybridization aCGH on this patient in order to map the exact region of the duplication, and demonstrated that the patient actually had a triplication within 11q23.3. We compare the clinical features of our two patients with those previously reported to further delineate the phenotype of isolated distal 11q duplication. Our study also demonstrates the clinical usefulness of whole genome high resolution aCGH analysis as a powerful molecular cytogenetic tool capable of detecting genomic imbalances due to cytogenetically visible but uncertain rearrangements. © 2009 WileyLiss, Inc.

Chromosome 22 band q11.2 has been recognized to be highly susceptible to subtle microdeletions and microduplications, which have been attributed to the presence of several large segmental duplications; also known as low copy repeats LCRs. These LCRs function as mediators of nonallelic homologous recombination NAHR, which results in these chromosomal rearrangements as a result of unequal crossover. The four centromeric LCRs at proximal 22q11.2 have been previously implicated in recurrent chromosomal rearrangements including the DiGeorgeVelocardiofacial syndrome DGVCFs microdeletion and its reciprocal microduplication. Recently, we and others have demonstrated that the four telomeric LCRs at distal 22q11.2 are causally implicated in a newly recognized recurrent distal 22q11.2 microdeletion syndrome in the region immediately telomeric to the DGVCFs typically deleted region. Here we report on the clinical, cytogenetic, and array CGH studies of a 4.5yearold girl with history of failure to thrive, developmental delay DD, and relative macrocephaly. She carries a paternally inherited ∼2.1 Mb microduplication at distal 22q11.2, which spans approximately 34 annotated genes, and is flanked by two of the four telomeric 22q11.2 LCRs. We conclude that the four telomeric LCRs at distal 22q11.2 can mediate both deletions and duplications in this genomic region. Both deletions and duplication of this region present with subtle clinical features including mild to moderate mental retardation, DD, and mild dysmorphic features. © 2008 WileyLiss, Inc.

Here we report on a patient with an interstitial deletion on the longq arm of chromosome 1 who presents with a unique constellation of anomalies including brachydactyly type E, Müllerian agenesis, growth hormone deficiency, as well as other abnormalities. We present the clinical details of this patients presentation, the skeletal findings, and provide characterization of the deletion at the molecular level. We postulate that these skeletal anomalies are distinctive to 1q deletions involving the 1q24q25 region. © 2008 WileyLiss, Inc.

No abstract.

Susceptibility of the chromosome 22q11.2 region to rearrangements has been recognized on the basis of common clinical disorders such as the DiGeorge/velocardiofacial syndrome (DG/VCFs). Recent evidence has implicated low‐copy repeats (LCRs); also known as segmental duplications; on 22q as mediators of nonallelic homologous recombination (NAHR) that result in rearrangements of 22q11.2. It has been shown that both deletion and duplication events can occur as a result of NAHR caused by unequal crossover of LCRs. Here we report on the clinical, cytogenetic and array CGH studies of a 15‐year‐old Hispanic boy with history of learning and behavior problems. We suggest that he represents a previously unrecognized microdeletion syndrome on chromosome 22 band q11.2 just telomeric to the DG/VCFs typically deleted region and encompassing the BCR gene. Using a 32K BAC array CGH chip we were able to refine and precisely narrow the breakpoints of this microdeletion, which was estimated to be 1.55–1.92 Mb in size and to span approximately 20 genes. This microdeletion region is flanked by LCR clusters containing several modules with a very high degree of sequence homology (>95%), and therefore could play a causal role in its origin. © 2007 Wiley‐Liss, Inc.

We report on an 8‐month‐old girl with a novel unbalanced chromosomal rearrangement, consisting of a terminal deletion of 4p and a paternal duplication of terminal 11p. Each of these is associated with the well‐known clinical phenotypes of Wolf–Hirschhorn syndrome (WHS) and Beckwith–Wiedemann syndrome (BWS), respectively. She presented for clinical evaluation of dysmorphic facial features, developmental delay, atrial septal defect (ASD), and left hydronephrosis. High‐resolution cytogenetic analysis revealed a normal female karyotype, but subtelomeric fluorescence in situ hybridization (FISH) analysis revealed a der(4)t(4;11)(pter;pter). Both FISH and microarray CGH studies clearly demonstrated that the WHS critical regions 1 and 2 were deleted, and that the BWS imprinted domains (ID) 1 and 2 were duplicated on the der(4). Parental chromosome analysis revealed that the father carried a cryptic balanced t(4;11)(pter;pter). As expected, our patient manifests findings of both WHS (a growth retardation syndrome) and BWS (an overgrowth syndrome). We compare her unique phenotypic features with those that have been reported for both syndromes. © 2007 Wiley‐Liss, Inc.

We report on an 8‐year‐old girl with near‐complete trisomy 17p syndrome due to a de novo unbalanced t(14;17)(p11.2;p11.2). She has features consistent with the previously described cases with complete trisomy 17p, including pre‐ and post‐natal growth retardation, motor and mental retardation, skeletal anomalies, clinodactyly of the 5th finger, hypertrichosis, as well as facial characteristics including microcephaly, receding forehead, ptosis, low‐set malformed ears, smooth philtrum, high‐arched palate, and a short broad neck. Fluorescence in situ hybridization showed that the breakpoints were p11.2 for both chromosome 14 and 17. Microsatellite analysis showed that the duplicated 17p was of paternal origin, and indicated that the breakpoint involving 17p11.2 is most likely located within the ∼1‐Mb segment from the centromere, and not involving the proximal Smith–Magenis syndrome (SMS) low copy repeat. We compare the clinical features of our patient with those previously reported to further delineate the phenotype of complete trisomy 17p syndrome. © 2006 Wiley‐Liss, Inc.

Erba: Takeda/Millenium: Research Funding; Pfizer: Consultancy, Other: grant; Celgene: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Takeda/Millenium: Research Funding; Pfizer: Consultancy, Other: grant; Incyte: Consultancy, Speakers Bureau; Amgen: Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Astellas: Research Funding; Incyte: Consultancy, Speakers Bureau; Jazz: Consultancy, Speakers Bureau; Astellas: Research Funding; Seattle Genetics: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Amgen: Research Funding; Novartis: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Astellas: Research Funding; Agios: Consultancy, Speakers Bureau; Agios: Consultancy, Speakers Bureau; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Novartis: Consultancy, Speakers Bureau; Amgen: Research Funding; Amgen: Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Astellas: Research Funding; Seattle Genetics: Consultancy, Research Funding; Janssen: Research Funding; Janssen: Research Funding; MacroGenics: Consultancy; MacroGenics: Consultancy; Pfizer: Consultancy, Other: grant; Juno: Research Funding; Juno: Research Funding; Pfizer: Consultancy, Other: grant; Agios: Consultancy, Speakers Bureau; Agios: Consultancy, Speakers Bureau; Seattle Genetics: Consultancy, Research Funding; Incyte: Consultancy, Speakers Bureau; Seattle Genetics: Consultancy, Research Funding; Incyte: Consultancy, Speakers Bureau; Jazz: Consultancy, Speakers Bureau; Takeda/Millenium: Research Funding; Immunogen: Consultancy, Research Funding; Jazz: Consultancy, Speakers Bureau; Takeda/Millenium: Research Funding; Celgene: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; MacroGenics: Consultancy; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; MacroGenics: Consultancy; Celgene: Consultancy, Speakers Bureau; Juno: Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Juno: Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Immunogen: Consultancy, Research Funding; Jazz: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding. Papadantonakis:Agios pharmaceuticals: Honoraria, Other: advisory board.

Introduction: The role of maintenance treatment in patients with high-risk Acute Promyelocytic Leukemia (APL) in the era of ATO/ATRA is unclear.

Both cytogenetic and molecular genetic studies can contribute to the management of patients with cancer. In some cases, genetic markers are specific to particular tumor types and are useful in diagnosis. This can be helpful in distinguishing histologically similar tumors that may respond differently to treatment and can sometimes be of prognostic value. Genetic markers can also be tools for following the response of a tumor to therapy, providing a sensitive means to detect relapse. This introductory unit considers some of the types of genetic changes that occur in association with malignancies, as well as major approaches used in their detection. © 2017 by John Wiley & Sons, Inc.

The goal of any clinical laboratory should be to provide patients with the most accurate test results possible. This is accomplished through various overlapping programs that continuously monitor and optimize all aspects of a test, including decisions by the laboratory to offer a test, the decision of providers to request the test, the testing itself, and the reporting of results to the referral source and patient. The levels at which test performance and accuracy can be optimized are encompassed under quality control (QC) and quality assurance (QA). The monitoring of QC and QA problems allows for the integration of these parameters into a total quality management program. This unit reviews QC and QA guidelines, in addition to discussing how to establish a quality assurance program. Curr. Protoc. Hum. Genet. 82:8.2.1‐8.2.10. © 2014 by John Wiley & Sons, Inc.

No relevant conflicts of interest to declare.

Abstract 182