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.

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.

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.

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.

Transient neonatal diabetes due to activating mutation in the ABCC8 gene encoding SUR1.

We report a 2 month male child presenting with diabetic ketoacidosis (DKA) and seizures treated with intravenous fluids and intravenous insulin infusion till the ketoacidosis was reversed, thereafter responding well to sulphonylureas and at age of 13 months going into complete remission. At age of 11 mo developmental delay in the form of negative neck holding and inability to sit without support was seen. The child is 3 yr of age now ,euglycemic without any insulin or oral hypoglycemic agents but has severe developmental delay. Genetic analysis was negative for mutations of KCNJ11, 6q24, Glucokinase and IPF-1 genes. A mutation R1183W was found in the ABCC8 gene encoding SUR1, which was the cause of neonatal diabetes in this case.

Differential association of tumour necrosis factor-alpha single nucleotide polymorphism (-308) with tuberculosis and bronchial asthma.

BACKGROUND: Tumour necrosis factor (TNF)-alpha is a pleiotropic, pro-inflammatory cytokine of 17 kDa, whose gene is localized on the short arm of chromosome 6. It has a G-308A polymorphism in the promoter region, which is known to be associated with its differential production; the A allele being the high producer. The circulating level of TNF-alpha is under genetic control and implicated in the pathophysiology of asthma and tuberculosis. Since raised levels of TNF-alpha have been found in asthma and tuberculosis, we looked for the association of TNF-alpha G-308A polymorphism in patients with these diseases. METHODS: A total of 300 blood samples from patients (155 with asthma, 145 tuberculosis) and 211 normal healthy controls were collected. The G-308A polymorphism was studied using amplification refractory mutation system analysis. RESULTS: The distribution of G/A alleles in the two patient groups when compared with normal controls revealed a statistically significant association with asthma (p = 0.016) but not with tuberculosis (p = 0.178). CONCLUSION: The data support the common variant common disease hypothesis, which emphasizes that common genetic variations may participate as critical players in inciting common diseases.

Real-time quantitative PCR analysis of amplified DNA on chromosomes 4p15.2 and 6q23-24 from formalin-fixed, paraffin-embedded breast cancer tissues.

This study was performed to detect amplification of DNA sequences on chromosomes 4p15.2 and 6q23-24, obtained from formalin-fixed, paraffin-embedded, breast-cancer tissues. The prognostic relevance of the amplification was also demonstrated. DNA from formalin-fixed, paraffin-embedded tumor and corresponding normal tissues of 53 patients with breast cancer was extracted and amplified by real-time quantitative PCR technique. Amplification of the DNA sequences on chromosomes 4p15.2 and 6q23-24 was detected in 23 (43%) and 32 (60%) cases, respectively. Thirty-six (68%) cases showed amplification on both or one of the chromosomes. These frequencies are similar to that obtained from fresh samples in our previous study. In addition, amplification of the DNA on chromosomes 4p15.2 and / or 6q23-24 was predominantly observed in tumors with invasive ductal carcinoma. The findings in this study demonstrate that DNA extracted from formalin-fixed, paraffin-embedded breast tumors can be used to determine amplification of DNA sequences on selective chromosomal regions. We also suggest that the amplified DNA on chromosomal regions 4p15.2 and 6q23-24 might be involved in the development and progression of breast cancer.

High Frequency of Genetic Alterations in Non-small Cell Lung Cancer Detected by Multi-target Fluorescence In Situ Hybridization

Detection of genetic alterations could provide a tool as an adjuvant for the diagnosis of non-small cell lung cancer (NSCLC) and to define patients at risk for early relapse. In this study, a multi-target fluorescence in situ hybridization (FISH) assay was conducted to investigate the correlation between the alterations of chromosomes, including 5p15.2, 6p11.1-q11, 7p12, and 8q24.12-q24.13 (LaVysion Test), and clinicopathological variables, and to clarify the potential of the multi-target FISH assay in 37 NSCLC. The most notable finding was the higher frequency of a gain in chromosome 5p15.2 in early-stage (I+IIa) lung cancers. The frequency of the gain was 81.3% (16/22) in stage I tumors. The frequencies of gains in 6p11.1-q11 and 8q24.12-q24.13 were 61.5% (8/13) and 84.6% (11/13) in stage IIIa cancers, as compared with lower frequencies in stage I tumors at 25.0% and 31.3%, respectively. There was also a significant difference in the histological type. Our results suggest that a gain in 6p11.1-q11 and 8q24.12-q24.13 plays an important role in tumor progression and is associated with histological differentiation. On the other hand, gene amplification in the 5p region was one of the most consistent alterations in early-stage lung cancer, and thus a series of genes in the critical 5p15.2 region might potentially associated with the development of lung cancer.

Hemocromatosis, ¿diagnóstico tardío e infradiagnóstico? / Hemochromatosis, late diagnosis or underdiagnosis?

La Hemocromatosis Hereditaria es un desorden del metabolismo del hierro de carácter hereditario. La sustitución de cisteína por tirosina en el aminoácido 282(C282Y) y la sustitución de histidina por ácido aspártico en el aminoácido 63 (H63D) son las dos mutaciones del gen HFE relacionadas con la enfermedad, ambas tienen una alta prevalencia en adultos con antepasados de origen europeo. La sobrecarga férrica determinada por estas mutaciones y su depósito a nivel de distintos órganos es responsable de los síntomas de la enfermedad. La población del Uruguay de origen mayoritariamente europeo hace pensar en que se deberían implementar conductas de diagnóstico precoz y eventualmente de screening de esta enfermedad

Estudio de asociación entre la fisura labiopalatina no sindrómica y marcadores de microsatélite ubicados en 6p / Association study between non syndromic cleft lip palate and microsatellite markers located in 6p

Background: Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common craniofacial developmental defect. Association studies have suggested that a clefting locus is located on chromosome 6p at or near two possible loci, Factor 13A (FI3A) in the region 6p 25-24 and HLA at 6p 21.3. Aim. To test the hypothesis on the possible presence of a major gene on chromosome 6p associated with NSCLP. Patients and methods: We carried out an association study on a sample of unrelated NSCLP patients from multiplex (Mx) and simplex (Sx) families, of their unaffected relatives and in control individuals. DNA was analyzed with three PCR markers close to the putative NSCLP locus, dinucleotide repeats at loci D6S89, D6S109 and D6S105. PCR products were resolved by PAGE and visualized by silver staining. Statistical analysis was performed by means of c2 log ratio. Results: Significant differences were observed when comparing the allele frequency distribution of D6S89 in patients with NSCLP and controls and in patients with NSCLP-Mx and controls. No significant differences were observed for patients with NSCLP-Sx. D6S109 and D6S105 showed no significant differences in any of the comparisons. Conclusions: Our results support the hypothesis that a NSCLP locus maps on 6p23 very close to D6S89. Results for D6S109 and D6S105 do not show a clear association. Differences observed between NSCLP-MX and Sx families seem to represent different etiologic entities. The results of the present study, plus those already published for candidate loci, TGFA and MSX1, support the hypothesis that several interacting major genes participate in the etiology of NSCLP