Síndrome de deleção 6q: relato de caso de um achado raro no Amazonas, Brasil / Deletion 6q syndrome: case report of a rare finding in Amazonas, Brazil

Objetivos: Síndrome da deleção 6q é considerada uma anomalia cromossômica rara. Assim, nosso objetivo foi relatar um caso de um menino com essa síndrome, em Manaus/Amazonas. Descrição do caso: Menino com quatro anos de idade que apresenta atraso do crescimento e do desenvolvimento neuropsicomotor, dificuldades de ganho de peso e anormalidades na retina. A análise citogenética do paciente revelou cariótipo com 46, XY, del(6)(q25-qter). Conclusões: Este relato demonstrou a importância das análises citogenéticas para o diagnóstico preciso das anomalias congênitas, pois auxiliam no encaminhamento de tratamentos adequados aos pacientes e na ampliação de conhecimento científico relacionado a essa deleção.

Aims: Deletion 6q syndrome is considered a rare chromosomal anomaly. Thus, our objective was to report a rare case of a boy with 6q deletion syndrome. Case description: 4-year-old boy with delayed growth and neuropsychomotor development, weight gain difficulties and retinal abnormalities. Karyotypic analysis of the patient revealed karyotype 46, XY, del (6) (q25-qter). That is, a deletion in the long arm of one of the chromosome 6, specifically in the distal region of the long arm of the 6q25 band up to the 6qter band. Conclusions: This report demonstrates the importance of cytogenetic analyzes for the accurate diagnosis of congenital anomalies, as they assist in referring appropriate treatments to patients and in expanding scientific knowledge related to this deletion.

Prenatal diagnosis for a pedigree affected with Wolf-Hirschhorn syndrome due to a subtle chromosomal translocation / 中华医学遗传学杂志

OBJECTIVE@#To make molecular diagnosis of an infant affected with severe developmental delay and multiple birth defects, assisting prenatal diagnosis for the second pregnancy.@*METHODS@#Standard G-banded karyotyping was performed for the fetus and his parents. Single nucleotide polymorphism array (SNP array) was used to detect submicroscopic chromosomal aberration. Fluorescence in situ hybridization (FISH) was employed to determine the parental origin of the aberration.@*RESULTS@#Both the proband and the fetus harbored a 5.4 Mb distal 4p deletion and a 6.9 Mb distal 6q duplication. FISH confirmed that the mother has carried a balanced translocation involving 4p and 6q.@*CONCLUSION@#The unbalanced chromosomal aberration in the proband and the fetus were both derived from the mother. Both patients showed a Wolf-Hirschhorn syndrom phenotype and partial phenotype of 6q trisomy. SNP array combined with FISH are essential for the detection of cryptic chromosomal aberrations which may be missed by coventional karyotyping analysis.

Inversiones cromosómicas (anomalías estructurales poco frecuentes) asociadas a fenotipo normal, dudoso y patológico / Chromosomal inversions (Slight structural anomalies) associated to normal, doubtfull and pathological phenotypes

Las inversiones son reordenamientos intracromosómicos originados por dos rupturas en un cromosoma seguidas de la reinserción del fragmento rotado en 180º. Dependiendo si involucra o no al centrómero pueden ser pericén tricas o paracéntricas. La incidencia es 0.09 a 0.49/1.000. Las inversiones son rearreglos estructurales aparentemente equilibrados, por lo que la mayoría de los individuos portadores tienen fenotipos normales y una minoría tienen fenotipos patológicos (probablemente por alteración en la secuencia de genes o variación en la función de éstos por efectos de cambio de posición). Se presentan tres casos de inversiones detectas por la técnica de Bandeo G y confirmadas por Hibridación In Situ Fluorescente (FISH). Caso 1: INVERSION PARACENTRICA FAMILIAR DEL CROMOSOMA 13 ASOCIADA A RETRASO MENTAL Y DISMORFIAS. El exhaustivo análisis del árbol genealógico y el estudio cromosómico al mayor número posible de individuos permitió confirmar la asociación inversión/fenotipo patológico en este grupo familiar. 13 de 17 miembros son portadores de inv(13)(q31q32)inh.ish inv(13)(q31q32) (wcp13+). Caso 2: INVERSION PARACENTRICA DEL CROMOSOMA 6 DE NOVO EN RECIEN NACIDO CON RETRASO MADURATIVO GLOBAL Y RETRASO DEL CRECIMIENTO INTRAUTERINO. En este caso no es posible adjudicar que, el fenotipo afectado se deba a la inversión. Cariotipo: 46,XY,add(6)(q21)dn.ish inv(6)(q21q27)(wcp6+). Caso 3: INVERSION PERICENTRICA DEL CROMOSOMA 12 EN OVODONANTE. Dicha inversión no parece tener efecto sobre el fenotipo, ya que es una paciente con coeficiente intelectual normal y no presenta malformaciones congénitas. Cariotipo: 46,XX,inv(12)(p12q14).ish inv(12) (p12q14)(wcp12+). Este reporte de casos muestra los tres fenotipos posibles de una inversión: patológico, dudoso y normal. Es el primer reporte de una inv(13) que confiera fenotipo patológico.

The inversions are intrachromosomal rearrangements which occur when a single chromosome undergoes two breaks and the region between it's rotates 180 degrees before rejoining. Depending on whether or not it include the centromere, they can be pericentric or paracentric. The incidence is 0.09 to 0.49/1,000. The inversions are apparently balanced structural rearrangements, so the most of the carrier individuals show normal phenotypes and a minority have pathological phenotypes (probably due to variation in their function due to changes in position). Three cases of inversions detected by the G Banding technique and confirmed by Fluorescence In Situ Hybridization (FISH) are presented. Case 1: FAMILIAL PARACENTRIC INVERSION OF CHROMOSOME 13 ASSOCIATED WITH MENTAL RETARDATION AND DISMORPHIA. The exhaustive analysis of the pedigree and the chromosomal study to the greatest possible number of individuals confirmed the inversion/pathological phenotype association in this family group. 13 of 17 members are carriers of inv(13)(q31q32)inh.ish inv(13)(q31q32)(wcp13+). Case 2: PARACENTRAL INVERSION DE NOVO OF CHROMOSOME 6 IN NEWBORN WITH GLOBAL MATURITY DELAY AND DELAY OF INTRAUTERINE GROWTH. In this case it is not possible to adjudge that, the affected phenotype is due to the inversion. Karyotype: 46,XY,add(6)(q21)dn.ish inv(6)(q21q27)(wcp6+). Case 3: PERICENTRIC INVERSION OF CHROMOSOME 12 IN OVODONANT. This inversion does not seem to have an effect on the phenotype, since it is a patient with normal IQ and does not present congenital malformations. Karyotype: 46,XX,inv(12)(p12q14).ish inv(12) (p12q14)(wcp12+). This case report shows the three possible phenotypes of an inversion: pathological, questionable and normal. It is the first report of an inv(13) that confers pathological phenotype. Key words: chromosomal inversion, G Banding, phenotype, structural rearrangement, fluorescence in situ hybridization.

Genetic analysis of a child with cleidocranial dysplasia and 6q21-q22.31 microdeletion / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To carry out genetic analysis on a child with developmental delay and multiple malformation.</p><p><b>METHODS</b>The karotypes of the child and her parents were analyzed with routine chromosomal G-banding. Their genomic DNA was analyzed with array comparative genomic hybridization (aCGH).</p><p><b>RESULTS</b>The karyotype of the proband was determined as 46,XX,del(6)(q22),inv(6)(p21.1q21), while no karyotypic abnormality was detected in her parents. aCGH has identified in the child a de novo 800 kb deletion encompassing the RUNX2 gene at 6p21.1 and a de novo 11.79 Mb deletion at 6q21-q22.31.</p><p><b>CONCLUSION</b>Both of the de novo deletions are pathogenic. Deletion of the RUNX2 gene probably underlies the cleidocranial dysplasia in the patient, while the 6q21-q22.31 deletion may result in malformation of the brain.</p>

Prenatal diagnosis and genetic analysis of a fetus with 6q27 microdeletion / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the origin and pathogenicity of a chromosomal aberration for a fetus and analyze the possible mechanism.</p><p><b>METHODS</b>The karotypes of the fetus and its parents were analyzed with routine G-banding. Their genomic DNA was also analyzed with array comparative genomic hybridization (aCGH).</p><p><b>RESULTS</b>No karyotypic abnormality was detected at cytogenetic level for the fetus and its parents. aCGH has identified a de novo 2.04 Mb deletion at 6q27 in the fetus. The region involves candidate genes responsible for structural brain abnormalities. The area flanking the chromosomal breakpoint contains a 2410 bp sequence rich in palindromes which can form stable secondary structures.</p><p><b>CONCLUSION</b>The de novo 6q27 deletion is pathogenic. The 6q27 deletion may be responsible for the structural brain abnormalities in the fetus. The palindrome sequence flanking the chromosomal breakpoint may be involved the formation of the 6q27 deletion.</p>

Un caso de deleción parcial 1p36. 1 y trisomía parcial 6p diagnosticadas por cariotipo / A case of partial 1p36. 1 deletion and partial trisomy 6p diagnosed by karyotype

La deleción de la región cromosómica 1p36 es una de las anomalías subteloméricas más frecuentes y causa rasgos dismórficos distintivos. Por otro lado, la trisomía distal del brazo corto del cromosoma 6 es una anormalidad cromosómica poco frecuente de fenotipo variable. Objetivo: Presentar el caso de un paciente con ambas alteraciones cromosómicas, y resaltar la vigencia e importancia del cariotipo como herramienta diagnóstica en dismorfología. Caso clínico: Lactante de 2 meses de edad con múltiples anomalías craneofaciales, hemangioma en la nuca, fosita sacra, acortamiento rizomélico, pies y manos pequeños, criptorquidia unilateral izquierda e hipotonía. Además, antecedente de restricción del crecimiento intrauterino. Producto del octavo embarazo de una mujer G8A7C1 de 28 años. Con estos hallazgos inespecíficos en el fenotipo se solicitó cariotipo que mostró una deleción parcial de 1p36.1 y una trisomía parcial de cromosoma 6p. Conclusión: El cariotipo convencional sigue siendo una herramienta importante para el etiológico en pacientes con anomalías congénitas (múltiples), mostrando en este caso una deleción parcial de 1p36.1 y una trisomía parcial de cromosoma 6p, alteraciones cromosómicas estructurales.

The deletion of chromosomal region 1p36 is one of the most common sub-telomeric microdeletion syndromes and has distinctive dysmorphic features. On the other hand, partial trisomy of the short arm of chromosome 6 is a rare chromosomal abnormality with a variable phenotype. Objective: To report a case with both chromosome abnormalities, and to highlight the importance of the karyotype as a diagnostic tool in dysmorphology. Clinical case: The case of is presented of a two month-old infant with several craniofacial anomalies, neck haemangioma, sacral pit, rhizomelic shortening, small hands and feet, left unilateral cryptorchidism, and hypotonia. The infant also suffered intrauterine growth restriction and is the product of the eighth pregnancy of a 28 years old woman. Due to the unspecific findings in phenotype, a karyotype was requested, which showed a partial deletion of 1p36.1 and a partial trisomy of chromosome 6. Conclusion: The development of new techniques in molecular biology has improved diagnostic possibilities in medical genetics. However, the traditional karyotype remains as an important diagnostic tool in patients with multiple congenital anomalies.

Analysis of chromosomal abnormalities by CGH-array in patients with dysmorphic and intellectual disability with normal karyotype / Análise de anomalias cromossômicas por CGH-array em pacientes com dismorfias e deficiência intelectual com cariótipo normal

ABSTRACT Objective To investigate chromosomal abnormalities by CGH-array in patients with dysmorphic features and intellectual disability with normal conventional karyotype. Methods Retrospective study, carried out from January 2012 to February 2014, analyzing the CGH-array results of 39 patients. Results Twenty-six (66.7%) patients had normal results and 13 (33.3%) showed abnormal results - in that, 6 (15.4%) had pathogenic variants, 6 (15.4%) variants designated as uncertain and 1 (2.5%) non-pathogenic variants. Conclusion The characterization of the genetic profile by CGH-array in patients with intellectual disability and dysmorphic features enabled making etiologic diagnosis, followed by genetic counseling for families and specific treatment.

RESUMO Objetivo Avaliar microalterações cromossômicas por CGH-array em portadores de dismorfias e deficiência intelectual com cariótipo normal. Métodos Estudo retrospectivo, realizado no período de janeiro de 2012 a fevereiro de 2014, analisando os resultados de CGH-array de 39 pacientes. Resultados Apresentaram resultados normais 26 (66,7%) pacientes; 13 (33,3%) tiveram resultados alterados, a saber: 6 (15,4%) com variantes patogênicas, 6 (15,4%) com variantes pertencentes à categoria designada como incerta, e 1 (2,5%) com variantes não patogênicas. Conclusão A caracterização do perfil genético por CGH-array nos pacientes com deficiência intelectual e dismorfias possibilitou complementar o diagnóstico etiológico, permitindo a realização do aconselhamento genético para as famílias e tratamento específico.

Cytogenetic and molecular characterization of a patient with partial 6q trisomy and 1q monosomy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze a girl with moderate mental retardation and speech and language disorders with cytogenetics technique and next-generation sequencing (NGS).</p><p><b>METHODS</b>G-banding chromosome analysis was used to ascertain the karyotype of the child and her parents, and NGS was used for determining the size and origin of the abnormal chromosome fragment. Mate-pair and PCR were used to determine its parental origin.</p><p><b>RESULTS</b>The karyotype of the child was determined to be 46,XX,add(1)(q44)dn, while her parents were both normal. NGS revealed that the child has harbored a partial trisomy of 6q24.3-q27, and the breakpoint was mapped to at 6q24.3q27. In addition, a 2.5 Mb microdeletion at 1q44 was found in the patient.</p><p><b>CONCLUSION</b>No recognizable phenotype was associated with 1q44 deletion. The abnormal phenotypes presented by the child may be attributed to the 6q24.3-q27 triplication. Compared with conventional cytogenetic analysis, NGS has a much higher resolution and great accuracy.</p>

Improved identification for trisomy 9p and partial trisomy 6q presented in a patient by array-based comparative genomic hybridization / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze the genetic cause for a child with growth retardation and mental retardation and discuss the application of array-based comparative genomic hybridization (aCGH) in its molecular genetic diagnosis.</p><p><b>METHODS</b>Conventional karyotyping of peripheral blood for the family was carried out. aCGH was performed to further ascertain the size and origin of the additional chromosome fragments.</p><p><b>RESULTS</b>In the trio family here, the karyotype of the father was normal, the karyotype of the mother was 46,XX, t(6;9)(q26;q21)and the proband child's was 47,XX,+der(9)?t(6;9)(q26;q21). aCGH showed that the extra chromosomal fragments originated from chromosome 9p24.3-q21.13 and the size was 78.26 Mb, and the repeat region included the 9p trisomy's clinical area. At the same time, it was confirmed that 6q26-q27 was trisomic and the fragment that related to development delay was 6.6 Mb. We determined that the proband's karyotype was 47,XX,+der(9)t(6;9)(q26;q21.13)mat finally.</p><p><b>CONCLUSION</b>The patient's abnormal chromosome has originated from her mother with balance translocation. The duplications of 9p24.3-q21.13 and 6q26-q27 may lead to growth retardation and mental retardation. Accompanied with the cytogenetic methods, aCGH can accurately identify the origin and size of the abnormal chromosomes, contributing to the genetic analysis.</p>

First Case of Diffuse Large B-Cell Lymphoma Subtype of Monomorphic Post-Transplant Lymphoproliferative Disorder With 3q27 Translocation

No abstract available.

Application of chromosome microarray analysis for prenatal diagnosis of a fetus with partial duplication of 1p and uniparental disomy of chromosome 6 / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the genetic cause for a fetus with structural anomaly, and to correlate the phenotype with the genotype.</p><p><b>METHODS</b>Amniotic fluid was obtained following the revelation of structural anomaly by ultrasonography. Cell culture and direct DNA extraction were performed in parallel. G-banded karyotyping analysis and chromosome microarray analysis (CMA) were subsequently carried out.</p><p><b>RESULTS</b>G-banded karyotyping has suggested the fetus to be a normal male. However, CMA analysis has revealed the presence of a mosaic 3.24 Mb duplication of 1p36.33p36.32 (24%) and uniparental disomy (UPD) of chromosome 6. The genetic diagnosis for the fetus was therefore 46,XY, arr 1p36.33 p36.32(849,466-4,090,472)×2-3, (6)×2 hmz. The anomaly can probably explain the ultrasound findings in the fetus.</p><p><b>CONCLUSION</b>Compared with conventional cytogenetic methods, CMA has greater resolution and throughput, and can serve as a more efficient platform for the detection of chromosomal microdeletion, microduplication, loss of heterozygosity and UPD.</p>

Renal cell carcinoma with t(6;11)(p21.2;q13)/MALAT1-TFEB fusion: a clinical and pathological analysis / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features, immunophenotype, differential diagnosis and prognosis of renal cell carcinoma (RCC) associated with t(6;11)(p21.2;q13)/MALAT1-TFEB gene fusion.</p><p><b>METHODS</b>A total of 9 cases of such rare tumor were selected for clinicopathologic, immunohistochemical and molecular analysis, with review of literature.</p><p><b>RESULTS</b>The age of the patients ranged from 21 to 42 years (mean=31.3 years). The patients included four men and five women. Histologically, 4 of the 9 cases studied showed classic morphologic features of TFEB RCC, with hyaline material, pigments and psammoma bodies frequently identified. The remaining 5 cases demonstrated uncommon morphology, mimicking perivascular epithelioid cell neoplasm, clear cell RCC, chromophobe RCC or papillary RCC. Immunohistochemical study showed that TFEB and vimentin were positive in all cases. Most of the tumors studied also expressed Ksp-cadherin, E-cadherin, CD117, HMB45, Melan A and Cathepsin K. CKpan showed immunostaining in only 1 case. The staining for TFE3, CD10 and CK7 were all negative. TFEB gene rearrangement was detected in all the 9 cases studied using fluorescence in-situ hybridization. MALAT1-TFEB fusion gene was identified in 2 cases by polymerase chain reaction and direct sequencing. TFEB RCC seemed to be an indolent tumor. During a mean follow-up of 31 months, none developed tumor recurrence, progression, or metastasis.</p><p><b>CONCLUSIONS</b>TFEB fusion-associated RCC is a rare neoplasm, tends to occur in young age group and carries an indolent behavior. Diagnosis relies on clinicopathologic findings and immunohistochemical analysis. TFEB break-apart FISH assay is a reliable tool in confirming the diagnosis.</p>

Correlation between expression of SIL-TAL1 fusion gene and deletion of 6q in T-cell acute lymphoblastic leukemia / 中国实验血液学杂志

The present study was designed to investigate the prevalence and clinical significance of SIL-TAL1 rearrangements in T-cell acute lymphoblastic leukemia (T-ALL). The incidence of SIL-TAL1 rearrangements was analyzed by nest real-time quantitative polymerase chain reaction (RT-PCR) in 68 patients with T-ALL. Karyotypic analysis was performed by conventional R-banding assay and array-based comparative genomic hybridization (array-CGH). The results showed that SIL-TAL1 rearrangements were identified in 10/26 (38.5%) pediatric and 2/42 (4.8%) adult T-ALL cases, which indicate a pediatric preference for SIL-TAL1 rearrangements in T-ALL. Two different transcripts were detected in 6/12(50%) T-ALL samples. Abnormal karyotypes were detected in 6 out of 11 cases (54.5%) and a deletion of the long arm of chromosome 6 was observed in 4 cases. Array-CGH results of 2 T-ALL cases with SIL-TAL1 rearrangement revealed that this fusion gene was resulted from a cryptic deletion of 1p32, and the overlap region of 6q deletion was 6q14.1-16.3. These cases with SIL-TAL1 fusion had a higher white blood cell (WBC) count and higher serum levels of lactate dehydrogenase (LDH) than cases without SIL-TAL1 fusion. It is concluded that SIL-TAL1 rearrangements are associated with loss of heterozygosity of chromosomal 6q, and SIL-TAL1-positive patients are younger than SIL-TAL1-negative patients. In contrast to the cases without SIL-TAL1 fusion, there are many adverse prognostic factors in the cases with SIL-TAL1 fusion, such as higher WBC count and higher LDH levels.

Analysis of Acute Myeloid Leukemia in Korean Patients with Sole Trisomy 6

No abstract available.

Derivative chromosome 11 in a child resulting from a complex rearrangement involving chromosomes 3, 6 and 11 in father: Significance of parental karyotyping.

The presence of derivative chromosome in a child with phenotypic features necessitates the need of parental karyotyping to ascertain the exact amount of loss or gain of the genetic material. The aim of this study was to emphasize the importance of parental karyotyping. Cytogenetic evaluation of the proband and his father were carried out at Laboratory. Cytogenetic analysis was performed on phytohemagglutinin stimulated cultures. The derivative chromosome 11 in proband was ascertained to have additional material from chromosome 6p arising from complex chromosomal rearrangement in the father. Karyotyping is the basic, cost-effective preliminary investigation in a child with mental subnormality or congenital anomalies.

Dysmorphic features and congenital heart disease in chromosome 6q deletion: A short report.

In this report, we describe a one and a half year old girl showing terminal deletion of long arm of chromosome 6q. The associated abnormalities such as congenital heart disease, mental retardation, and dysmorphic features are described. Cytogenetic studies with GTG banding showed 46,XX,del(6)(q24→qter). Karyotype of the parents was normal suggesting a denovo event.

Molecular genetics of functional articulation disorder in children / 中国当代儿科杂志

Genetic factors are an important cause of functional articulation disorder in children. This article reviews some genes and chromosome regions associated with a genetic susceptibility to functional articulation disorders. The forkhead box P2 (FOXP2) gene on chromosome 7 is introduced in details including its structure, expression and function. The relationship between the FOXP2 gene and developmental apraxia of speech is discussed. As a transcription factor, FOXP2 gene regulates the expression of many genes. CNTNAP2 as an important target gene of FOXP2 is a key gene influencing language development. Functional articulation disorder may be developed to dyslexia, therefore some candidate regions and genes related to dyslexia, such as 3p12-13, 15q11-21, 6p22 and 1p34-36, are also introduced. ROBO1 gene in 3p12.3, ZNF280D gene, TCF12 gene, EKN1 gene in 15q21, and KIAA0319 gene in 6p22 have been candidate genes for the study of functional articulation disorder.

Mosaic Ring Chromosome 6 in an Infant with Significant Patent Ductus Arteriosus and Multiple Congenital Anomalies

The clinical features of ring chromosome 6 include central nervous system anomalies, growth retardation, facial dysmorphism and other congenital anomalies. Ring chromosome 6 occurs rarely and manifests as various phenotypes. We report the case of mosaic ring chromosome 6 by conventional karyotyping in a 7-day-old male infant diagnosed with a large patent ductus arteriosus (PDA) with hypoplasia of aortic valve and aortic arch. These have not been previously reported with ring chromosome 6. He recovered from heart failure symptoms after ligation of the PDA. He showed infantile failure to thrive and delayed milestone in a follow-up evaluation. To the best of our knowledge, this is the first report of a Korean individual with ring chromosome 6 and hemodynamically significant PDA.

Characteristics of 11 patients with acute myeloid leukemia accompanied with karyotype aberration t(6;9) / 中国实验血液学杂志

This study was aimed to investigate the characteristics of 11 patients with acute myeloid leukemia (AML) accompanying with karyotype t(6;9). The laboratorial and clinical data were analyzed retrospectively, including immunophenotype analysis and result analysis of real-time quantitative PCR detection. The results showed that a high prevalence of M2 was observed. Among 11 cases, 6 of M2, 2 of M4, 2 of M5 and 1 of MDS-RAEBT were found according to FAB criteria. Ten patients had high counts of peripheral white blood cells. Bone marrow dysplasia was seen in only 2 cases, and basophilia occurred in 4 cases. Six patients carried additional cytogenetic aberrations apart from t(6;9). Immunophenotypic analysis showed that all patients were positive for CD117, CD33, CD13, HLA-DR, CD38 and CD123. No NPM1 mutation was observed in all patients and a high level of WT1 was detected in all patients (7/7), out of 7 patients FLT3-ITD mutation was detected in only 3 patients. Follow-up details were available for 7 patients, one of whom died before chemotherapy, and the remaining 6 patients all had no response to IA or DA regimen. Among the 6 patients, 3 did not response to subsequently chemotherapy and all died from infections in a short period after diagnosis, the other 3 patients achieved a complete remission after alternative chemotherapy, but 2 relapsed in a short time and died. It is concluded that AML with cytogenetic aberration of t(6,9) is a distinct disease with a very poor prognosis. The first line chemotherapy such as IA or DA regimen is not effective to such patients, and the effective treatment needs further study.

Cytogenetic profile of Indian patients with de novo myelodysplastic syndromes.

Background & objectives: Myelodysplastic syndrome (MDS) is a clonal haematopoietic stem cell disorder characterized by ineffective haematopoiesis and leukaemia progression. Cytogenetic analysis has proven to be a mandatory part of the diagnosis of MDS as well as a major indicator for predicting clinical course and outcome. Studies on cytogenetics of MDS are reported mostly from the West and only a few are available from Asian countries. We report herein cytogenetic studies on 40 Indian patients with primary MDS to find out the occurrence and type of chromosome abnormalities and recurring defects. Methods: Cytogenetic analysis was done using GTG banding and karyotyped according to the International System for Human Cytogenetic Nomenclature (ISCN). Results: Of the 40 patients, 19 patients (47.5%) showed clonal karyotypic abnormalities with distribution as follows: 3 of 15 (20%) of refractory anaemia (RA), 4 of 7 (57%) of refractory anaemia with excess blasts-1 (RAEB-1), 4 of 6 (67%) of refractory anaemia with excess blasts 2 (RAEB-2), 2 of 3 (67%) of refractory anaemia with ring sideroblasts (RARS), 2 of 4 (50%) of refractory cytopenia with multilineage dysplasia (RCMD), none (0%) RCMD-ringed sideroblasts (RCMD-RS) and 4 patients with 5q syndrome. The frequent abnormalities observed in our study were -7, 5q-and trisomy 8. Interpretation & conclusions: Two rare chromosomal abnormalities (6q-, 3q-) were found with unknown prognostic significance. Hence, cytogenetic analysis may be incorporated in the routine diagnosis of MDS since there are racial differences in clinical pictures and the molecular events.