Constitutional 560.49 kb chromosome 2p24.3 duplication including the MYCN gene identified by SNP chromosome microarray analysis in a child with multiple congenital anomalies and bilateral Wilms tumor.

Fewer than 100 patients with partial chromosome 2p trisomy have been reported. Clinical features are variable and depend on the size of the duplicated segment, but generally include psychomotor delay, facial anomalies, congenital heart defect, and other abnormalities. We report a 560.49 kb duplication of chromosome 2p in a 13 month-old male with hydrocephaly, ventricular septal defect, partial agenesis of the corpus callosum, and bilateral Wilms tumor. After discovery of bilateral renal masses at four months of age, the child underwent neoadjuvant chemotherapy followed by right radical nephrectomy that revealed triphasic Wilms' tumor. A needle core biopsy on one of two lesions on the left kidney also revealed Wilms tumor. A partial left nephrectomy revealed focally positive margins that necessitated left flank radiotherapy. The tumor karyotype was 46,XY,t(7;8)(q36;p11)[8]/46,XY [12] while his constitutional karyotype was 46,XY, suggesting that the t(7;8)(q36;p11) was associated with the malignancy. Single nucleotide polymorphism (SNP) chromosome microarray analysis of peripheral blood identified a maternally-inherited 560.49 kb chromosome 2p24.3 duplication that involved four OMIM genes: NBAS, DDX1, MYCNOS, and MYCN. SNP array analysis of the tumor revealed the same 2p24.3 duplication. At present, the now 5-year-old boy continues to do well without clinical or radiographic evidence of recurrent disease. This case is instructive because the child's health insurer initially denied authorization for chromosome microarray analysis (CMA), and it took more than one year before such authorization was finally granted. That initial decision to deny coverage could have had untoward health implications for this child, as the identification of constitutional MYCN duplication necessitated surveillance imaging for a number of pediatric malignancies associated with MYCN overexpression/dysregulation.

22q11.2 deletion detected by endoscopic observation of pharyngeal pulsations in a child with submucous cleft palate and persistent velopharyngeal insufficiency.

22q11.2 microdeletion syndrome (22q11.2DS) is the most common syndrome associated with cleft palate and velopharyngeal insufficiency (VPI). Over 180 clinical features have been described. Most common features include: cardiac malformations, cleft palate, velopharyngeal insufficiency, characteristic facial features, hypotonia, behavioral disorders, and musculoskeletal disorders among several other fenotipical features. A case of 22q11.2DS confirmed by cytogenomic analysis is presented with review of the literature. Main clinical features were a submucous cleft palate (SMCP) with persistent VPI after palatoplasty, an ectopic left internal carotid artery and a prominent aortic root. VPI was corrected with a pharyngeal flap, tailored according to findings of videonasopharyngoscopy, videofluoroscopy and neck CT scan with contrast.

Macrocerebellum, epilepsy, intellectual disability, and gut malrotation in a child with a 16q24.1-q24.2 contiguous gene deletion.

Macrocerebellum is a rare condition characterized by enlargement of the cerebellum with conservation of the overall shape and cytoarchitecture. Here, we report on a child with a distinctive constellation of clinical features including macrocerebellum, epilepsy, apparent intellectual disability, dysautonomia, gut malrotation, and poor gut motility. Oligonucleotide chromosome microarray analysis identified a 16q24.1-q24.2 deletion that included four OMIM genes (FBXO31, MAP1LC3B, JPH3, and SLC7A5). Review of prior studies describing individuals with similar or overlapping16q24.1-q24.2 deletions identified no other reports of macrocerebellum. These observations highlight a potential genetic cause of this rare disorder and raise the possibility that one or more gene(s) in the 16q24.1-q24.2 interval regulate cerebellar development.

Velopharyngeal insufficiency, submucous cleft palate and a phonological disorder as the associated clinical features which led to the diagnosis of Jacobsen syndrome. Case report and review of the literature.

Jacobsen syndrome is an uncommon but well-known contiguous gene syndrome caused by partial deletion involving the long arm of chromosome 11. Most common features include: psychomotor impairment, facial dysmorphism, and thrombocytopenia. Cleft palate has been rarely reported. A case of Jacobsen syndrome confirmed by cytogenomic analysis is presented with review of the literature. Main clinical features were phonological disorder, submucous cleft palate (SMCP) and velopharyngeal insufficiency (VPI). VPI was corrected surgically according to findings of videonasopharyngoscopy and videofluoroscopy. It is concluded that clinicians should consider that VPI associated with SMCP may be the main manifestations of a chromosomal syndrome.

Mutations in CEP57 cause mosaic variegated aneuploidy syndrome.

Using exome sequencing and a variant prioritization strategy that focuses on loss-of-function variants, we identified biallelic, loss-of-function CEP57 mutations as a cause of constitutional mosaic aneuploidies. CEP57 is a centrosomal protein and is involved in nucleating and stabilizing microtubules. Our findings indicate that these and/or additional functions of CEP57 are crucial for maintaining correct chromosomal number during cell division.

Composite biclonal marginal zone lymphoma of lung and chronic lymphocytic leukemia: pathologic, phenotypic, cytogenetic, and molecular study.

The simultaneous diagnosis of marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is rare. This study reports a patient with composite synchronous biclonal occurrence of MALT lymphoma of the lung and CLL/SLL. The morphology of the lung and peripheral blood showed features of MALT lymphoma and CLL, respectively. The cytogenetic evaluation of the lung specimen revealed a t(1;14) (p22;q32), a frequent genetic abnormality in MALT lymphoma. Flow cytometry analysis of the lung tissue showed features of MALT lymphoma and CLL/SLL with different light chain restriction, whereas the blood showed phenotypic evidence of CLL/SLL. Fluorescence in situ hybridization study of the blood showed a deletion of 13q14 and 17p13. Immunoglobulin heavy chain (IgH) gene rearrangement study of the lung tissue and blood showed a monoclonal IgH gene rearrangement with distinct light chain restriction, suggesting that the immunophenotypically different cell populations originated from separate clones.

Primary bone diffuse large B-cell lymphoma: clinicopathologic study of 21 cases and review of literature.

Primary bone diffuse large B-cell lymphomas (PB-DLBCL) are uncommon extranodal lymphomas. Herein, we report the clinical, pathologic, immunohistochemical, and molecular features of 21 cases of PB-DLBCL. The mean age of the patients was 54 years (range: 13 to 85 y). The male and female ratio was 1.6:1. The tumors consisted of diffuse sheets of large atypical cells or a polymorphous mixture of small-to-large cells with large multilobated nuclei, fine chromatin, and inconspicuous to prominent nucleoli. Twelve (57%) cases were non-germinal center B (GCB) and 9 (43%) were GCB subtype based on immunohistochemical classification. B-cell lymphomas (BCL)-2 was positive in 17/21 (81%), TP53 in 11/21 (52%) positive and the mean MIB-1 index was 57%. Polymerase chain reaction showed 10 cases with immunoglobulin heavy-chain (IGH) and 4 cases with IGH/BCL-2 gene rearrangement. The fluorescence in-situ hybridization analyses showed 14% of cases with BCL-6, 19% of cases with BCL-2, and 9% of cases with C-MYC gene rearrangement. Age <60 years and complete response to initial treatment were significant predictors of survival outcome (P< or =0.05). Even though no association was observed between the subtype of PB-DLBCL (GCB vs. non-GCB), BCL2, TP53, MIB1 index and overall survival (P>0.05), due to small sample size, and variability in treatment received, this analysis may be interpreted with caution.

Mosaic variegated aneuploidy without microcephaly: implications for cytogenetic diagnosis.

Mosaic variegated aneuploidy (MVA) is a rare condition characterized by multiple trisomies, rarely monosomies, and a non-specific phenotype including microcephaly, growth and mental retardation, mild malformations, and an increased risk of malignancy. We describe a patient with MVA in whom trisomy 19 mosaicism was originally suspected. The patient was the product of an uncomplicated term pregnancy and delivery. Significant findings were mental retardation, obesity, mild epicanthal folds, tapering fingers, relatively small hands and feet, alternating exotropia, nasal speech limited to short phrases, and generalized hypotonia. There is no family history for birth defects, mental retardation, or consanguinity. The initial peripheral blood chromosome study showed trisomy 19 in 4 of 31 metaphase cells. Because mosaic trisomy 19 is rare, the study was extended to 100 cells, wherein two cells with trisomy 8 were identified. A second blood karyotype was obtained and found to be 47,XX,+8[3]/47,XX,+19[3]/47,XX, +18[2]/47,XX,+9[1]/46,XX[91]. Skin fibroblast chromosome studies revealed a 46,XX karyotype in 120 cells examined. There was no evidence of premature centromere separation. Mutations in the BUB1B gene that encodes a key mitotic spindle checkpoint protein have been described in MVA; however, no mutations of this gene were identified in our patient. This case illustrates the importance of considering other possibilities when confronted with an extremely rare diagnosis such as mosaic trisomy 19. In addition, it shows the importance of not simply interpreting a low percentage of multiple aneuploidies as cell culture artifact, because an additional work-up to rule out MVA may be warranted since this diagnosis is associated with an increased risk of malignancy.