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M Urioste

Publications and source records attributed to M Urioste.

At least 19 recordsLinked to original sources
PubMed2006

A haplotype containing the p53 polymorphisms Ins16bp and Arg72Pro modifies cancer risk in BRCA2 mutation carriers.

Germline mutations in the BRCA1 and BRCA2 genes confer a high lifetime risk of developing breast and other cancers; however, remarkable differences exist regarding disease manifestation in mutation carriers. It has been suggested that other genetic and/or environmental factors modify not only the appearance but also the age of onset and type of tumor in BRCA1/2-associated cases. The aim of the present study was to investigate the role of two p53 polymorphisms (c.97-147ins16bp and c.215c>g, p.Arg72Pro) as potential modifiers. For this purpose we investigated the possible association between the two polymorphisms and disease status in 447 BRCA1/2 mutation carriers belonging to 170 Spanish breast and/or ovarian cancer families. Genotype and haplotype analyses revealed that the presence of a specific haplotype carrying the allele without the 16-bp insertion and the variant allele for the Arg72Pro (No Ins-72Pro haplotype) was associated with an earlier age of onset in BRCA2 mutation carriers. We found an increased risk of developing a first primary tumor (breast or ovarian) before 35 years of age for individuals who carried at least one No Ins-72Pro haplotype (OR: 2.69; 95% CI: 1.15-6.29; P=0.022). We confirmed these data by a functional study in which we compared different p53 genotypes in relation to their apoptotic response after cell treatment with a cytotoxic drug (AraC). Our results revealed a decrease in p53 apoptotic rate associated with the No Ins-72Pro haplotype.

Adult↗
PubMed2004

Lhermitte-Duclos disease and Cowden disease: clinical and genetic study in five patients with Lhermitte-Duclos disease and literature review.

BACKGROUND: Lhermitte-Duclos Disease (LDD) is an infrequent cerebellar disorder characterized by focal or diffuse enlargement of cerebellar folia presenting as a slowly growing mass in the posterior fossa. Over the past decade its association with Cowden disease (CD) has been recognized with increasing frequency. This latter disease is a genetic condition leading to the presence of multiple hamartomas and neoplasias which affect mainly the skin, thyroid, breast and genito-urinary and gastro-intestinal tracts. It has even been hypothesized that LDD and CD constitute a single entity. This work is aimed to analyse to what extent this association was present in patients treated for LDD at our institution. METHOD: We reviewed the medical records of five patients and performed clinical studies for CD manifestations, among them, genetic investigation for PTEN mutations. The International Cowden Consortium Criteria were applied for the diagnosis of CD. FINDINGS: Four of the five patients treated for LDD were also diagnosed of CD. The genetic study found PTEN mutations in two of them. Interpretation. LDD has been found to be closely related to CD in this series, in accordance with previous literature. However, the absence of CD diagnosis in one of the patients led us to suggest that, despite the strong association between these two diseases, LDD can also appear as an isolated condition.

Adult↗
PubMed2003

Characterization of the A673 cell line (Ewing tumor) by molecular cytogenetic techniques.

The A673 cell line was established from a patient with a primary rhabdomyosarcoma (RMS), which is referred to in the literature either as a Ewing tumor (ET) or as RMS. Although the two tumoral types are associated with specific and well-characterized translocations, no cytogenetic report on this cell line has been published. We characterized the A673 cell line using a combination of spectral karyotyping (SKY), fluorescence in situ hybridization (FISH), and reverse transcriptase polymerase chain reaction (RT-PCR), which revealed the presence of a complex karyotype and a translocation involving chromosomes 11 and 22 and the fusion of EWS and FLI1 genes, both events being specific to ET. Neither cytogenetics nor molecular alterations specific to RMS were found.

Chromosome Aberrations↗
PubMed2002

Complex cytogenetic abnormalities including telomeric associations and MEN1 mutation in a pediatric ependymoma.

Ependymomas are neuroectodermal tumors of the brain and spinal cord. Some recurrent cytogenetic aberrations have been reported in these tumors, including alterations involving chromosomes 22, 6, and 11. However, consistent molecular alterations have not been identified in ependymal tumors. We studied a recurrent ependymoma in a 3-year-old patient by standard cytogenetic and molecular analysis of TP53 and MEN1 genes. In the present case, we found many of the cytogenetic features previously described as being recurrent in ependymomas, including unstable telomeric alterations. Furthermore, we detected a novel acquired heterozygous mutation in the MEN1 gene. The chromosomal instability produced by the telomeric alterations and the mutation in the MEN1 gene could be important events in the tumorigenesis of ependymomas.

Base Sequence↗
PubMed2002

Identification of ins(8;21) with AML1/ETO fusion in acute myelogenous leukemia M2 by molecular cytogenetics.

A high percentage of cases of acute myelogenous leukemia (AML) of the M2 subtype show a rearrangement between the AML1 and ETO genes. The detection of the AML1/ETO fusion has clinical relevance because patients with this subtype have a good prognosis. We present the results of conventional and molecular cytogenetic studies in a patient with acute myelogenous leukemia French-American-British M2 classification, who had a complex karyotype involving chromosomes 8 and 21. Dual-color fluorescence in situ hybridization (FISH) using the AML1/ETO probe demonstrated a recombination of both genes on an add(8) chromosome. The use of other FISH probes (CEP8, c-myc and TEL21) and spectral karyotyping indicated that AML1/ETO fusion occurred as a consequence of a previously undescribed ins(8;21)(q22;q22.1q22.3).

Child↗
PubMed2001

Chromosomal changes pattern and gene amplification in T cell non-Hodgkin's lymphomas.

T cell non-Hodgkin's lymphomas are a heterogeneous group of lymphomas with poor prognosis, and whose genetic alterations are not well understood. Comparative genomic hybridization (CGH) is a technique that allows the identification of DNA imbalances without cytogenetic studies. We have studied 37 samples from 29 T cell non-Hodgkin's lymphomas (25 peripheral and four lymphoblastic lymphomas) by CGH in order to detect DNA sequence copy number changes of putative importance in the biology and prognosis of these neoplasms. We detected abnormal CGH profiles in 16/27 (59%) of samples at diagnosis, a ratio that increased to 66% (23/37) when we included the relapsed samples. The most common recurrent changes were gains related to the X chromosome, either the whole chromosome or partially the Xq26-27 bands (19%). Other recurrent changes included gains of bands 9q34, gains of chromosomes 17, 19, and 20, and complete or partial deletions of chromosome 13 (10%). Cancer-related genes located at Xq26-28 region were analyzed by Southern blot and fluorescence in situ hybridization (FISH). Low level amplification of some of these genes was detected by this technique confirming the results obtained by CGH in this region. The detection of abnormal CGH profiles in these T cell lymphomas could have clinical implications. Patients with abnormal CGH profiles showed significant associations with advanced stage of disease, overexpression of P53, and higher proliferative index.

Blotting, Southern↗
PubMed2001

Fluorescence in situ hybridization study of TEL/AML1 fusion and other abnormalities involving TEL and AML1 genes. Correlation with cytogenetic findings and prognostic value in children with acute lymphocytic leukemia.

BACKGROUND AND OBJECTIVES: The TEL/AML1 fusion is the most common genetic abnormality found in childhood acute lymphoblastic leukemias (ALL). Although it is very difficult to identify by conventional cytogenetic techniques it can be readily detected using fluorescence in situ hybridization (FISH). We carried out cytogenetic and FISH studies on 42 children with ALL in order to know the frequency of this translocation in our population, the incidence of TEL and/or AML1 gene alterations, and their correlation with clinical evolution and prognosis. In addition, we performed reverse transcription polymerase chain reaction (RT-PCR) in some cases, confirming the feasibility of FISH techniques in the detection of this translocation. DESIGN AND METHODS: Bone marrow samples were obtained from 42 childhood ALL patients. The copy number of AML1 and TEL genes were studied using fluorescent in situ hybridization with a dual color DNA probe specific for the AML1 and TEL genes. RESULTS: We found a frequency of TEL/AML1 fusion of 17% in our sample. Double TEL/AML1 fusion, lack of TEL signal and extra AML1 signals were frequent additional FISH abnormalities. Duplication of a chromosomal complement, deletion of chromosome 12p arm, and polysomies of chromosome 21 are plausible explanations for these additional FISH findings. However, a relatively high proportion of our cases (9.5%) presented specific amplification of AML1. A statistically significant difference in prognosis was found between patients with and without these additional AML1 or TEL FISH alterations (p<0.02), which could be related to the presence of specific karyotypes. INTERPRETATIONS AND CONCLUSIONS: The frequency of TEL/AML1 fusion is similar to that found in other populations (17%). We found that FISH analysis of AML and TEL is related to the evolution of the disease. The absence of alterations in these genes revealed by FISH could be indicative of bad prognosis, while the presence of alterations is related to a good evolution. Our results suggest that interphase FISH analysis to search for alterations in AML and TEL genes could be extremely useful for complementing cytogenetic studies and for providing additional information about the possible outcome of the disease in patients with ALL.

Adolescent↗
PubMed1999

Analysis of the INK4a/ARF locus in non-Hodgkin's lymphomas using two new internal microsatellite markers.

Inactivation of the INK4a/ARF locus is a frequent event in non-Hodgkin's lymphomas (NHLs), which may be attributed to deletion, point mutation, and 5' CpG methylation at its promoter region. In the present study we evaluated the occurrence of deletions and genetic instability of INK4a/ARF locus in 30 paired normal and tumor samples of B cell NHLs by conducting an allelotypic analysis with two new polymorphic markers, one located at the intron 1 of p16INK4a gene and the other one placed downstream exon 1beta of p19ARF. Comparison of these results with those obtained in a previous paper using flanking markers (D9S171, D9S942, D9S958 and IFNA) allowed us to detect two new cases of microsatellite instability (L-446 and L-442), and to confirm the occurrence of LOH at the INK4a/ARF locus in one tumor (M-3770). On the contrary, this locus is not affected in three different tumors (L-421, L-272 and L-159) which exhibited LOH at some of the flanking markers.

Chromosome Mapping↗
PubMed1999

[MLL rearrangements in acute leukemias].

PURPOSE: In present study we have studied MLL rearrangements in a serie of acute myeloid, lymphoblastic and biphenotypic leukaemias. PATIENTS AND METHODS: We analyzed a total of 11 cases: 9 acute myeloid leukaemias (M4 and M5 subtypes in FAB classification), 1 lymphoid leukaemia, and 1 acute biphenotypic leukaemia. We studied bone marrow samples from all patients by using conventional cytogenetic techniques and fluorescence in situ hybridization (FISH) with an MLL probe. We also analyzed the correlation between clinical features and genetic results. RESULTS: Cells from 6 patients showed to contain MLL rearrangements and these arose in all types of leukaemias included in this study. Some MLL rearrangements were detected by FISH in kariotypically normal cases or without cytogenetic evidence of 11q23 aberration. MLL gene duplication has been observed in two cases with M4 and biphenotypic leukaemia, respectively. The presence of MLL gene rearrangements does not shape a group of patients with a common clinical pattern. CONCLUSIONS: MLL rearrangements occurs in a wide variety of leukemias. These rearrangements should be screened by FISH techniques, taking into account that gene duplications could arise in cases with normal karyotype. MLL rearrangements appear to have a considerable clinicopathologic heterogeneity.

Adult↗
PubMed1998

[Achondroplasia: molecular study of 28 patients].

BACKGROUND: The main goal of the study is to investigate in the Spanish population the value of searching for the Gly380Arg mutation in the transmembrane domain of fibroblast growth factor receptor-3 (FGFR3#) as the basis for the molecular diagnosis of achondroplasia. PATIENTS AND METHODS: Twenty eight achondroplastic patients were studied. Genomic DNA obtained from blood was used to amplify using PCR a 164 bp segment of FGFR3 encompassing the transmembrane domain. The occurrence of the G-->A transition and of the G-->C transversion at the first base of codon 380 were investigated by digestion with the restriction enzymes Sfcl and Mspl followed by electrophoretic analysis of the products. RESULTS: All achondroplastic patients were found to be heterozygous for the Gly380Arg mutation, as a consequence of the G-->A transition in 27 cases and of the G-->C transversion in the remaining patient. None of these changes were found in control subjects including a hypochondroplastic patient. CONCLUSIONS: The identification of the Gly380Arg mutation can be used in Spain for conclusive diagnosis of achondroplasia. The guanine at the first position of codon 380 of FGFR3 exhibits similarly increased frequency of mutation than in other populations, an thus it is unlikely that the genetic background of the population determines the mutation potential of this guanine.

Achondroplasia↗
PubMed1998

Anencephaly and faciocranioschisis: evidence of complete failure of closure 3 of the neural tube in humans.

We report on a patient with median cleft of face and anencephaly as apparent consequence of delayed closure of the most rostral end of the neural tube. No other structural anomalies were found. To our knowledge, this child represents the first description of an isolated and complete failure of closure 3 of the neural tube and supports the hypothesis of a multi-site model of neural tube closure in humans.

Anencephaly↗
PubMed1997

Epidemiological analysis of the schisis association in the Spanish registry of congenital malformations.

Since its description by Czeizel [1981: Am J Med Genet 10:25-35], there has been general acceptance of the schisis association as a distinct entity although, to the best of our knowledge, no other epidemiological study has confirmed its existence. Here we present an epidemiologic study on schisis defects and their associations with each other in children with and without blastogenetic defects. This study demonstrates that most cases represent the dysmorphogenetic response of the primary developmental field.

Blastocyst↗
PubMed1997

Proximal partial 5p trisomy resulting from a maternal (19;5) insertion.

We present a case with a partial duplication 5p11-->5p13.3 resulting from a maternal ins (19,5)(p11;p11-p13.3). The diagnosis was confirmed by FISH and complement component determinations. The clinical picture was similar to those described in patients with complete duplication of the short arm and in some patients with partial 5p duplications, affecting at least band 5p13. A special significance of band 5p13 in the clinical severity of 5p duplications is discussed.

Abdomen↗
PubMed1997

Tetrasomy 5p mosaicism due to an extra i(5p) in a severely affected girl.

We present a case of mosaic 5p tetrasomy. The mosaicism 46,XX/47,XX,+i(5p) was found at different ratios in blood lymphocytes, skin fibroblasts, and chondrocytes. The origin of the extra isochromosome was confirmed by FISH. The clinical picture corresponds to that described in trisomy 5p patients, although it was more severe than the two previously reported cases of mosaic 5p tetrasomy. No correlation between clinical severity and proportion of tetrasomic cells in blood or fibroblasts was found in these cases.

Abnormalities, Multiple↗
PubMed1997

Giant-cell chondrodysplasia in a male infant with clinical and radiological findings resembling the Piepkorn type of lethal osteochondrodysplasia.

We report on a patient whose clinical, radiologic, and histopathologic findings are compatible with the Piepkorn type of lethal short-limb osteochondrodysplasia, but who also showed multinucleated giant chondrocytes in cartilage. Multinucleated giant cells are an unusual finding in osteochondrodysplasias, having been reported in atelosteogenesis type I and boomerang dysplasia. This uncommon histopathologic finding and the clinical and radiographic findings strongly support the diagnosis of boomerang dysplasia in the present patient. Our patient supports the previously suggested existence of an entity including atelosteogenesis and boomerang dysplasia. If this is so, the current patient and that described by Piepkorn et al. [1977: Teratology 16:345-350] could represent the most severe clinical expression of that condition.

Cartilage↗