1/30. The role of trisomy 8 in the pathogenesis of chronic eosinophilic leukemia.A case of chronic eosinophilic leukemia (CEL) manifesting as spinal cord compression by an extradural eosinophilic chloroma in a 32-year-old Chinese man was presented, who subsequently developed extramedullary transformation at the skin and then peritoneal cavity. Cytogenetic study of bone marrow cells at diagnosis showed a clonal karyotypic abnormality of trisomy 8 ( 8), which on fluorescence in situ hybridization (FISH) was shown to be present in a clone of abnormal eosinophils, hence showing the neoplastic nature of the eosinophilic proliferation. There was another population of abnormal eosinophils that did not show 8. At blastic transformation, all blast cells in ascitic fluid were shown by FISH to harbor 8. These findings suggest that 8 in this case may have arisen from clonal evolution and is not the primary genetic event in leukemogenesis, but 8 most probably imparts a further survival advantage to the clone responsible for subsequent blastic transformation.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/30. Distal 5q trisomy resulting from an X;5 translocation detected by chromosome painting.We describe the case of a 13-year-old girl with an apparently de novo unbalanced translocation resulting in the presence of additional chromosomal material on the short arm of one x chromosome, which was detected by conventional G-banding studies. fluorescence in situ hybridization (FISH) using the Chromoprobe Multiprobe-M protocol confirmed that the additional chromosomal material originated from chromosome 5. The karyotype of this patient is now established to be 46,X,der(X) t(X;5)(p22.3;q33), with a deletion of Xp22.3-pter and partial trisomy of 5q33-qter. The distal 5q trisomy genotype has been associated with clinical signs that include growth and mental retardation, eczema, craniofacial anomalies, and malformations of heart, lungs, abdomen, limbs, and genitalia. Our patient also has short stature, a prominent nasal bridge, a flat philtrum, a thin upper lip, dental caries, and limb and cardiac malformations, but she appears to be mildly affected compared with previously reported cases. This is the first case of distal 5q trisomy arising from a translocation with the x chromosome. Replication studies on this patient show that the derivative t(X;5) chromosome is late replicating in almost all cells examined, which indicates that this chromosome is preferentially inactivated. However, the translocated segment of chromosome 5 appears to be early replicating, which implies that the trisomic 5q segment is transcriptionally active. We cannot determine from these studies whether all or only some genes in this segment are expressed, but this patient's relatively mild clinical signs suggest that the critical region(s) that contribute to the distal 5q trisomy phenotype are at least partly suppressed. A review of other patients with X-chromosome translocations indicates that many but not all of them also have attenuated phenotypes. The mechanism of inactivation of autosomal material attached to the x chromosome is complex, with varying effects on the phenotype of the patients that depend on the nature of the autosomal chromatin. Replication studies are of limited utility in predicting expression of autosomal genes involved in X-chromosome translocations.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/30. Malignant giant cell tumor of synovium (malignant pigmented villonodular synovitis).CONTEXT: Pigmented villonodular synovitis (PVNS) is a well-recognized entity that has the potential for extensive local destruction, even though it rarely metastasizes. Rare reports of malignant forms are recorded in the literature. We observed 2 patients in whom examples of PVNS followed an aggressive course with multiple recurrences, metastasis, or degeneration to an appearance resembling malignant fibrous histiocytoma. OBJECTIVE: We studied the occurrence and persistence of aneuploidy for chromosomes 5 and 7 in 2 patients with clinically aggressive PVNS. DESIGN: fluorescence in situ hybridization was performed for the detection of chromosomes 5 and 7 in the primary lesions, recurrences, and metastases in 2 examples of PVNS. RESULTS: fluorescence in situ hybridization demonstrated small but significant numbers of cells with trisomies for chromosomes 7 and/or 5 in both the primary and recurrent lesions of both patients. CONCLUSIONS: The presence of consistent chromosomal trisomies (5 and 7) in both patients' examples of PVNS suggests a neoplastic nature for this lesion. The persistence of these trisomies in the primary lesions, recurrences, and metastases supports a molecular link between the primaries, recurrences, and metastases despite changes in morphologic features. The presence of persistent trisomies in the recurrent and metastatic lesions supports the concept of malignant PVNS.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/30. holoprosencephaly: the Maastricht experience.holoprosencephaly (HPE) is a developmental field defect with impaired cleavage of the embryonic forebrain as the cardinal feature. The prevalence is about 1 in 11.000-20.000 in live births and 1 in 250 during embryogenesis. In most cases, craniofacial abnormalities are associated and reflect in 80% of cases the degree of severity. The severity is of marked variability and ranges from cyclopia to minimal craniofacial dysmorphism, such as mild microcephaly with a single central incisor. The etiology of HPE is very heterogeneous and comprises environmental factors (e.g. maternal diabetes) and genetic causes. Approximately 50% of HPE cases are associated with a cytogenetic abnormality (the most common of which is trisomy 13) or a monogenic syndrome. Based on recurrent cytogenetic abnormalities, there are at least 12 genetic loci that likely contain genes implicated in the pathogenesis of HPE. Currently, four human HPE genes are known: SHH at 7q36, ZIC2 at 13q32, SIX3 at 2p21 and TGIF at 18p11.3. Over the past 13 years, 16 patients with HPE have been observed at the Department of Clinical genetics at Maastricht. Some of them are briefly presented in order to emphasize the spectral nature of HPE and the etiological heterogeneity. One patient appeared to have a partial 18p deletion due to a maternal cryptic translocation t(1:18) and, in addition, a SHH mutation. The mildest affected patient presented with microcephaly and a single maxillary incisor; she had a submicroscopic 7q deletion. Finally, we propose a protocol of etiological work-up of HPE cases.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/30. SKY assessment of two karyotypes with 0-6 supernumerary marker/ring chromosomes and review of previously reported cases with two or more markers.A 7-month-old boy with developmental delay and congenital abnormalities and a 58-year-old man with mental retardation, impaired speech, and dysmorphic features were referred for cytogenetic studies. The peripheral blood chromosome studies of Patient 1 had a de novo mosaic karyotype with 2-6 supernumerary marker chromosomes. Patient 2 had a mosaic karyotype with 1-5 supernumerary marker chromosomes and normal cells. All markers appeared to have a centromere by C-banding and also by fluorescence in situ hybridization (FISH) using all centromere probe for Patient 1. The majority of the markers appeared like rings. Except for one marker in Patient 1 and 2-3 markers in Patient 2 with discernible >5 Mb euchromatin, the rest of the markers were minute and some appeared to have barely discernible euchromatin in C-banding or FISH. spectral karyotyping (SKY) was attempted to determine the origin of the marker chromosomes. Because some markers had barely any euchromatin, their classification was not clear cut and they were identified as derived from more than one chromosome. The SKY classification of the markers in Patient 1 was 1, 3, 5, 7, 11, 15, and 22 and in Patient 2 was 1, 5, 6, or 7. Patient 2 was lost to further follow-up studies. To confirm the recurring SKY classifications in Patient 1, centromere probes for chromosomes 1, 3, 5, 7, 11, 15, and 22 were used. The markers were negative for 1, 3, and 11 but positive for 7, 15, and 22 and probably 5. Since 5 centromere probe cross hybridizes with 1 and 19, the weak signal on the marker/s in successive hybridization did not give a definitive answer. Also, the 5 paint probe was not conclusive because of the minute size of the marker. In some metaphases, two markers were derived from 5 or 22. For clinical considerations, the marker derived from 7, although variable in size, appeared to consistently have euchromatin, followed by 15, while 22 and 5 markers were mostly centromeric heterochromatin. The elastin gene probe that maps to 7q11.23, SNRPN gene that maps to 15q11.2, and TUPLE gene that maps to 22q11.2 did not give a signal on the markers. As expected for a majority of ring chromosomes, the pan telomere probe did not hybridize to any of the markers. This highly unusual karyotype was confirmed in the buccal epithelium using a mix of centromere 7 and 15 probes and the combination 14/22 probe. The ratio of additional FISH signals in the buccal mucosal cells was comparable to the ratios observed in the peripheral blood. In this study, we have attempted to consolidate the data on >/=2 marker cases to understand the analysis constraints, the range of clinical abnormalities, and the mechanisms involved. The literature was surveyed for multiple markers cases. A majority of the reported cases had two markers, either derived from the same chromosome or from two different chromosomes or two cell lines with different markers derived from the same chromosome. Cases with three or more markers were rare. The nature and extent of euchromatin content of the multiple markers appears to determine the phenotype. Frequently, multiple marker cases had small to minute markers. The clinical presentation varied from mild to severe. While two bisatellited markers may be associated with infertility, the phenotype in other cases ranged from borderline intelligence and mild dysmorphism to developmental delay, mental retardation, and congenital abnormalities.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
6/30. Supernumerary chromosome marker Der(22)t(11;22) resulting from a maternal balanced translocation.Derivative 22 [der(22)] syndrome is a rare disorder associated with multiple congenital anomalies including pre-auricular skin tags or pits, conotruncal heart defects, and profound mental retardation. Der(22)t(11;22) is one of the causes of supernumerary chromosome markers (mar) in humans. We present a boy with developmental delay and multiple anomalies consistent with the supernumerary der(22) syndrome. cytogenetic analysis showed an abnormal chromosome complement of 47, XY, mar in all 50 cells analyzed. The karyotype of his mother showed a reciprocal translocation over the distal bands 11q23 and 22q11, respectively, i.e., 46,XX,t( 11;22)(q23.3;q11.2), and that of his father was 46,XY. Thus, the nature of the supernumerary chromosome markers was of der(22)t(11 ;22)(q23.3;q11.2). The clinical features, including craniofacial dysmorphism, hypotonia, psychomotor retardation, heart defects, and urogenital anomalies, were the combined effects of partial trisomies for both distal 11q and pericentromeric 22q.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/30. Detoxifying death in the neonate: in search of meaningfulness at the end of life.At the end of life, when curative measures have failed to conquer the terminal nature of a disease, it is imperative to introduce healing measures that deal with the human suffering associated with illness. When dealing with critically ill neonates with lethal conditions, it may be necessary to institute healing measures at the beginning of life. In such cases, healing measures must incorporate customary palliative measures but should not be limited to them. The purpose of this paper is to describe two families' approaches to palliation at the end of life in their newborn infants with trisomy 18, a genetic abnormality usually associated with a markedly decreased life expectancy. We shall consider the concepts of interference versus intervention as we examine subtle medical differences between the two cases. We will address medical, legal, and ethical issues in each case, but special attention will be given to the provision of compassionate care. People face physical, mental, emotional, and spiritual challenges as they go through life. The families' approaches with their infants at the end of their lives may support the premise that the latter two challenges, emotional and spiritual, confront us the most at the end. Encouraging families to engage with their dying infants helps detoxify the experience and make it more meaningful.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
8/30. Relapse as acute monoblastic leukemia (AML-M5) of t(6;9) acute myeloblastic leukemia (AML-M2).Two patients with acute myeloblastic leukemia with t(6;9)(p23;q34) translocation and classified as AML-M2 relapsed as acute monocytic leukemia (AML-M5). trisomy 8 was found associated with t(6;9) at that time in both patients. Such changes in differentiation of leukemic cells have not previously been reported in this subtype of AML and add data favoring the pluripotent nature of the stem cell involved in leukemia with t(6;9).- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
9/30. A case of partial trisomy 4p syndrome presenting as severe hydronephrosis in utero.We describe the phenotypic features in a newborn infant with an unbalanced translocation 46,XY, der(22) inv(4) (p14p16.1) t(4;22) (p15.1;q13.31)pat. The phenotype was consistent with partial trisomy 4p syndrome. Severe bilateral hydronephrosis was diagnosed at a 31 week prenatal ultrasound scan. Both the patient phenotype and the partial trisomy are unusual, the latter due to the complex nature of the chromosomal rearrangement.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
10/30. Three cases with enlarged acrocentric p-arms and two cases with cryptic partial trisomies.In three cases, banding analysis revealed a normal karyotype except for an enlarged short arm of one chromosome 13 or 15. To clarify whether this enlargement was due to a heteromorphism or to a cryptic chromosomal trisomy, so-called cenM-FISH probe sets containing a microdissection-derived probe specific for the acrocentric human p-arms were applied. The results enabled us to confirm in one case and to exclude in two cases that the enlargement on the suspect chromosome was due to a p-arm polymorphism. M-FISH and/or microdissection were used to resolve the nature of the rearrangements, i.e., partial trisomies 6 and 19.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
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