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Biomedical subjects

F Ballesta

Publications and source records attributed to F Ballesta.

At least 37 records · Page 2Linked to original sources
PubMed1998

Prevalence of the Cys282Tyr and His63Asp HFE gene mutations in Spanish patients with hereditary hemochromatosis and in controls.

BACKGROUND/AIMS: A mutation (Cys282Tyr) of the HFE gene has recently been reported to be present in most of the patients with hereditary hemochromatosis of Northern European ancestry, but in a lower frequency in Italy. No data are so far available on the prevalence of these mutations in Spain. Therefore, we initiated the present study to determine if the reported Cys282Tyr HFE mutation is also the main cause of hereditary hemochromatosis in Spain. In addition, we investigated the presence of the His63Asp HFE mutation in patients and in controls. METHODS: Thirty-one hereditary hemochromatosis patients and 485 controls were screened for the Cys282Tyr and the His63Asp mutations, using polymerase chain reaction amplification of genomic DNA, followed by digestion with the restriction enzymes Rsa I or Dpn II, respectively, and the separation of the products by electrophoresis. RESULTS: Twenty-seven out of 31 (87.1%) hereditary hemochromatosis patients were homozygous for the Cys282Tyr mutation. None of the patients was homozygous for the His63Asp mutation, and two patients (6.5%) were compound heterozygous (Cys282Tyr/His63Asp). Only one of 512 (0.2%) controls was homozygous for the Cys282Tyr mutation, and 29 (5.7%) were heterozygous. The Cys282Tyr mutation is present with an allelic frequency of 90.3+/-7.5% in patients with hereditary hemochromatosis and 3.0+/-1.1% in controls. Twenty out of 487 (4.1%) controls were His63Asp homozygous, while 171 (35.1%) were heterozygous. The His63Asp mutation is present with an allelic frequency of 21.7+/-2.7% in controls. CONCLUSIONS: The high frequency of the Cys282Tyr mutation in hereditary hemochromatosis patients indicates that this mutation is the most common defect associated with hereditary hemochromatosis in Spain. The finding of some patients with the wild genotype at position 282 suggests the existence of other changes in the HFE gene or in other loci involved in the disease. We have found one of the highest allelic frequencies reported for the His63Asp mutation in our controls (21.7+/-2.7%).

Adult↗
PubMed1998

Molecular, cytogenetic, and clinical characterisation of six XX males including one prenatal diagnosis.

Cytogenetic analysis, fluorescent in situ hybridisation (FISH), and molecular amplification have been used to characterise the transfer of Yp fragments to Xp22.3 in six XX males. PCR amplification of the genes SRY, RPS4Y, ZFY, AMELY, KALY, and DAZ and of several other markers along the Y chromosome short and long arms indicated the presence of two different breakpoints in the Y fragment. However, the clinical features were very similar in five of the cases, showing a male phenotype with small testes, testicular atrophy, and azoospermia. All these patients have normal intelligence and a stature within the normal male range. In the remaining case, the diagnosis was made prenatally in a fetus with male genitalia detected by ultrasound and a 46,XX karyotype in amniocytes and fetal blood. Molecular analysis of fetal DNA showed the presence of the SRY gene. FISH techniques also showed Y chromosomal DNA on Xp22.3 in metaphases of placental cells. To our knowledge, this is the second molecular prenatal diagnosis reported of an XX male.

DNA-Binding Proteins↗
PubMed1997

Identification of Spanish familial Parkinson's disease and screening for the Ala53Thr mutation of the alpha-synuclein gene in early onset patients.

We initiated the present work in order to determine if the Ala53Thr mutation of the alpha-synuclein gene previously described by Polymeropoulos et al. [Science, 276 (1997) 2045-2047] could be detected in Spanish early onset Parkinson's disease (PD) patients. Thirty-four PD patients were evaluated. Of these, 13 were considered early onset patients (six familial and seven sporadic) and were included in the genetic study. We detected the presence of genetic anticipation in four kindreds with early onset PD members. The Ala53Thr mutation of the alpha-synuclein gene was absent in all patients. The results do not support a role for this mutation in our patients with early onset PD and, in agreement with the results previously reported, indicate that the Ala53Thr mutation of the alpha-synuclein gene is a rare cause of PD.

Adult↗
PubMed1997

The genotype 2/2 of the presenilin-1 polymorphism is decreased in Spanish early-onset Alzheimer's disease.

We have found a significantly lower frequency of the presenilin-1 (PS-1) intronic polymorphism 2/2 genotype in early-onset Alzheimer's disease (AD) patients without APOE epsilon4 alleles (2/2 = 0.054; P = 0.009) as compared to age matched non-epsilon4 controls (2/2 = 0.227). Moreover the average age of onset in AD patients with the PS-1 2/2 genotype is older than that in AD patients with a 1/2 genotype or with a 1/1 genotype. This data suggest a protective effect of the 2/2 genotype which would delay the age of onset in AD. Our results do not support an association between the 1/1 genotype and AD. However, a non-significant increase of the 1/1 genotype is found in non-epsilon4 AD patients (P = 0.20).

Age of Onset↗
PubMed1996

YAC and cosmid FISH mapping of an unbalanced chromosomal translocation causing partial trisomy 21 and Down syndrome.

Most cases of Down syndrome (DS) result from a supernumerary chromosome 21; however, there are rare cases in which DS is due to partial trisomy of chromosome 21, involving various segments of the chromosome. The characterization of cases of DS that are due to partial trisomy 21 allows the phenotype to be correlated with the genotype. We present a case with features of DS and a partial trisomy of chromosome 21 inherited from a paternal balanced translocation involving chromosomes 13 and 21. Fluorescence in situ hybridization analysis using yeast artificial chromosome (YAC) probes mapped the breakpoint to 21q22.1, within YAC 230E8, which contains markers CBR, D21S333 and D21S334. Further mapping using cosmids positioned the breakpoint proximal to CBR. The patient was also monosomic for the distal portion of chromosome 13 (q33-qter). Many phenotypic features of DS were present including hypotonia, flat occiput, flat facies, up-slanted palpebral fissures, epicanthic folds, flat nasal bridge, macroglossia, open mouth, small ears and a heart murmur. This case further supports the contention that the majority of the phenotypic features of DS map to 21q22-qter and further refines the location of some of them. In addition to the DS phenotype, the patient had a prominent upper maxilla with protruding upper incisors, and low levels of the coagulation factors VII and X, consistent with a syndrome resulting from monosomy 13q33-qter. Since some features overlap between the two syndromes, including severe mental retardation, it is unclear to what extent monosmy for 13q33-qter, trisomy for 21q22.1-qter, or a combination of both, contributed to the common features of the phenotype.

Adult↗
PubMed1994

Fragile X syndrome and the (CGG)n mutation: two families with discordant MZ twins.

The fragile X phenotype has been found, in the majority of cases, to be due to the expansion of a CGG repeat in the 5'-UTR region of the FMR-1 gene, accompanied by methylation of the adjacent CpG island and inactivation of the FMR-1 gene. Although several important aspects of the genetics of fragile X have been resolved, it remains to be elucidated at which stage in development the transition from the premutation to the full mutation occurs. We present two families in which discordance between two sets of MZ twins illustrates two important genetic points. In one family, two affected MZ brothers differed in the number of CGG repeats, demonstrating in vivo mitotic instability of this CGG repeat and suggesting that the transition to the full mutation occurred postzygotically. In the second family, two MZ sisters had the same number of repeats, but only one was mentally retarded. When the methylation status of the FMR-1 CpG island was studied, we found that the majority of normal chromosomes had been inactivated in the affected twin, thus leading to the expression of the fragile X phenotype.

Adolescent↗
PubMed1992

Submicroscopic deletions at the WAGR locus, revealed by nonradioactive in situ hybridization.

Fluorescence in situ hybridization (FISH) with biotin-labeled probes mapping to 11p13 has been used for the molecular analysis of deletions of the WAGR (Wilms tumor, aniridia, genitourinary abnormalities, and mental retardation) locus. We have detected a submicroscopic 11p13 deletion in a child with inherited aniridia who subsequently presented with Wilms tumor in a horseshoe kidney, only revealed at surgery. The mother, who has aniridia, was also found to carry a deletion including both the aniridia candidate gene (AN2) and the Wilms tumor predisposition gene (WT1). This is therefore a rare case of an inherited WAGR deletion. Wilms tumor has so far only been associated with sporadic de novo aniridia cases. We have shown that a cosmid probe for a candidate aniridia gene, homologous to the mouse Pax-6 gene, is deleted in cell lines from aniridia patients with previously characterized deletions at 11p13, while another cosmid marker mapping between two aniridia-associated translocation breakpoints (and hence a second candidate marker) is present on both chromosomes. These results support the Pax-6 homologue as a strong candidate for the AN2 gene. FISH with cosmid probes has proved to be a fast and reliable technique for the molecular analysis of deletions. It can be used with limited amounts of material and has strong potential for clinical applications.

Adult↗
PubMed1992

[Wilson's disease. A retrospective analysis of 12 cases].

We reviewed retrospectively 12 patients with Wilson's disease diagnosed during a 16-year period (1974-1989). The prevalence rate was 0.6 per 100,000 individuals. Clinical onset was hepatic (50%) or neurologic (50%), but at diagnosis (6.4 years later) 67% of patients showed several clinical manifestations: hepatic, neurologic, renal and haematologic. Among the essential diagnostic indices we find false negative results for Kayser-Fleischer ring (25%), serum ceruloplasmin (8%) and total serum copper (34%). Ten patients were treated with penicillamine. This drug was effective and well tolerated, although one patient (10%) developed membranous nephritis and required to change successively to BAL and trien. In a 61 months follow-up 5 patients (42%) died from severe liver failure. Patients with poor prognosis had a diagnostic delay and a liver failure degree significantly greater than patients with good prognosis. Our results suggest the following conclusions: a) in Spain the prevalence rate of Wilson's disease is near the lower reported rate; b) the early diagnosis of Wilson's disease is rare; c) diagnosis should be made only when several essential indices are positive; d) early hepatic transplantation showed carried out in patients with acute or chronic severe liver failure.

Age Factors↗
PubMed1990

Meiotic and sperm chromosome studies in a reciprocal translocation t(1;2)(q32;q36).

Meiotic and sperm chromosomes were studied in a man heterozygous for a reciprocal translocation t(1;2)(q32;q36). Forty-five meiotic metaphase I cells were obtained from semen samples: 86.6% were 22,XY,IV and 13.3% had synaptic anomalies that affected all or some of the bivalents. The quadrivalents observed had a ring configuration (92.3%) or a chain configuration (7.7%). A total of 105 sperm chromosome complements were analyzed: 41% resulted from an alternate segregation, and the percentage of unbalanced sperm was 59%; most of them (71%) resulted from an adjacent 1 segregation. The frequency of anomalies unrelated to the translocation (5.7% numerical and 14.1% structural anomalies) were within the normal range for control donors. There was a good correspondence between the percentage of cells with a ring IV (92.3%) and the proportion of 2:2 segregations (88.6%) and between the percentage of chain IV (7.7%) and the incidence of 3:1 segregations (11.4%).

Chromosomes, Human, Pair 1↗
PubMed1988

Y-body study in bone marrow precursors, peripheral blood cells and alveolar macrophages for demonstration of haemopoietic engraftment in allogeneic bone marrow transplantation.

The value of Y-body study for assessment of haemopoietic engraftment was analyzed in 50 consecutive patients submitted to allogeneic bone marrow transplantation (BMT) (sex-matched in 28 cases, sex-mismatched in 22). The study was performed weekly on bone marrow and peripheral blood smears in all cases, and alveolar macrophages were also studied in 15 patients in whom bronchoalveolar lavage was carried out because of concurrent respiratory disturbances. The analysis was performed blindly by 2 independent observers. In both sex-matched and sex-mismatched cases there was an absolute concordance between recipient and donor Y-body results, as well as with the simultaneous cytogenetic study. The engraftment of erythroid and granulopoietic lines was documented at day +14 in all cases of sex-mismatched BMT, whereas megakaryocyte and lymphocyte take was demonstrated at d +21. On the other hand, the results from alveolar macrophages were in accordance with those obtained in the simultaneous study of bone marrow precursors after BMT. The above results indicate that Y-body analysis is a simple and useful tool for the demonstration of bone marrow take in sex-mismatched BMT.

Blood Cells↗
PubMed1986

Cytogenetic studies in blast crisis of Ph-positive chronic granulocytic leukemia: results and prognostic evaluation in 52 patients.

Bone marrow cytogenetic (G-banding) studies were carried out in 52 patients with Ph-positive chronic granulocytic leukemia (CGL) at the time of diagnosis of blast crisis. In all cases, the Ph chromosome was due to the standard (9;22) translocation. Eighteen patients displayed the 46,Ph cell line unchanged, whereas additional chromosome abnormalities were observed in the remaining 34 patients (65.4%). Among the latter, numerical karyotypic changes were found in 31 patients and structural changes in 8 patients. Five patients displayed numerical and structural changes simultaneously. The most common chromosome numerical changes were an extra #8 (14 cases) and additional Ph chromosomes (11 patients); an i(17q) was the most frequently observed structural change (3 cases). These three aberrations were often combined; at least one of them was present in 21 patients, constituting 62% of the cases with new cytogenetic abnormalities at blast crisis. When comparing the clinical and hematologic characteristics, as well as the survival, of patients retaining the unchanged 46,Ph cell line and patients showing additional chromosome changes, no differences were found between the two groups of patients. However, a minority displaying a hypodiploid modal chromosome number survived significantly longer than the remaining patients.

Adult↗