Search PubMed⌕ Search

Biomedical subjects

R Galanello

Publications and source records attributed to R Galanello.

At least 109 records · Page 6Linked to original sources
PubMed1983

Globin gene mapping studies in Sardinian patients homozygous for beta zero Thalassaemia.

The genetic factors responsible for the relatively mild clinical phenotypes of some cases of homozygous beta zero thalassaemia (thalassaemia intermedia) in Sardinia have been evaluated. The frequency of deletion forms of alpha thalassaemia was higher in patients with thalassaemia intermedia (6/8) than in those with thalassaemia major (6/17). The beta globin gene clusters were also studied, first to determine whether there were any rearrangements of the gamma genes, and second to see whether the restriction fragment length polymorphism patterns (haplotypes) of the two groups of patients were similar. The structure of the gamma genes was normal in all the patients with the single exception of a thalassaemia major patient with a triplicated gamma gene arrangement. The beta globin gene cluster haplotypes of the two groups of patients were not significantly different. However, the frequency of the various haplotypes in the thalassaemic as compared to the normal (beta A) chromosomes was different. This finding is of potential value in the antenatal diagnosis of homozygous beta thalassaemia in this population.

Child↗
PubMed1983

Phenotypic effect of heterozygous alpha and beta 0-thalassemia interaction.

In this study, we carried out restriction endonuclease mapping in order to characterize the alpha-globin genotype of 10 Sardinian beta 0-thalassemia heterozygotes, all of whom presented with normal red blood cell indices and increased HbA2 levels. In 8 of these subjects, we found the deletion of two alpha-globin genes (-alpha/-alpha), and in the remaining two the deletion of a single alpha-globin gene (-alpha/alpha alpha). In three of these carriers with the (-alpha/-alpha) alpha-globin genotype and in one with the (-alpha/alpha alpha) genotype, we also found the glucose-6-phosphate dehydrogenase (G6PD) defect of the Mediterranean type. On the basis of these findings, we may conclude that the interaction of heterozygous beta 0-thalassemia with alpha-thalassemia, due to the deletion of either one or two alpha-globin genes, may lead to the production of red blood cells with normal indices. The association of the G6PD defect with this thalassemia gene complex may eventually contribute to this effect. We suggest, therefore, that screening programs for heterozygous beta-thalassemia in populations where alpha-thalassemia is also prevalent, should incorporate the determination of HbA2 in the first set of tests.

DNA↗
PubMed1983

Delta +-thalassemia in Sardinia.

We have defined a new type of delta-thalassemia in which beta-globin chain synthesis is incompletely suppressed. Homozygotes have unusually low HbA2 levels, and double heterozygosity for this delta-thalassemia gene and beta-thalassemia normalizes the HbA2 level. The delta-thalassemia occurs on a chromosome that is identifiable using polymorphic restriction endonuclease sites. We call this condition delta +-thalassemia, to distinguish it from the previously described delta 0-thalassemia syndromes in which no delta-globin chain synthesis occurs.

Chromosome Mapping↗
PubMed1983

A family with segregating triplicated alpha globin loci and beta thalassemia.

In this article we report a Sardinian family, in which a beta-thalassemia gene and a triple alpha-globin loci, counterpart of the rightward deletion type alpha-thalassemia-2, were segregating. The analysis of the genotype-phenotype correlations in the different family members allowed us to give an outline of the manifestations associated with different genotype combinations. The heterozygote for the triple alpha-loci showed no consistent abnormal clinical or hematologic characteristics and presented balanced alpha/beta-globin chain synthesis. In the homozygous state for this lesion, the only phenotypic expression was a slightly imbalanced globin chain synthesis. The combination of heterozygous beta-thalassemia with the heterozygous state for the triple alpha-globin loci produced no clinical manifestations and showed a hematologic phenotype indistinguishable from that of heterozygous beta-thalassemia. On the other hand, the combination of the homozygous state for the triple alpha-globin gene loci and the heterozygous state for beta-thalassemia produced a clinical picture of thalassemia intermedia with a very mild clinical course, minor increase of fetal hemoglobin (HbF) levels, and a pronounced imbalance of globin chain synthesis.

Adult↗
PubMed1982

Molecular comparison of delta beta-thalassemia and hereditary persistence of fetal hemoglobin DNAs: evidence of a regulatory area?

The hematological phenotypes of several Mediterranean patients with delta beta-thalassemia and hereditary persistence of fetal hemoglobin have been characterized. Although clinical and hematological characteristics are essentially superimposable in all heterozygous delta beta-thalassemics, these patients show typical G gamma/A gamma ratios in their Hb F, ranging from approximately 0.07 in Sardinian to approximately 0.15 in Sicilian and approximately 0.35 in Spanish patients. A gamma Sardinian-(isoleucine-75 leads to threonine) is found in Spanish patients and accounts for all of the A gamma production in heterozygotes, indicating that persistent production of gamma chains occurs cis to the delta beta-thalassemia gene. The molecular heterogeneity of these conditions is demonstrated by restriction enzyme mapping of DNA; Sicilian and Calabrian patients show a deletion starting from the delta-globin intron and extending several kilobases 3' to the beta-globin gene; in Spanish patients the deletion starts approximately 2-3 kilobases 5' to the delta-globin gene and extends well beyond the beta-globin gene. Comparison of these deletions with previously described ones in Negro and in a new Southern Italian case of hereditary persistence of fetal hemoglobin suggests that the deletion of a region centered at a cluster of repetitive sequences approximately 3.5 kilobases 5' to the delta-globin gene may be critical for the persistent expression of high levels of gamma-globin in hereditary persistence of fetal hemoglobin compared to delta beta-thalassemia. The concept that the deletion or mutation of specific areas (rather than nonspecific changes brought about by large deletions in the globin cluster) is important in determining the persistent expression of gamma-globin genes is supported by the finding of a nondeletion type of delta beta-thalassemia in Sardinians.

Chromosome Deletion↗
PubMed1982

The interaction of alpha thalassaemia with heterozygous beta thalassaemia.

The alpha globin genotypes of 55 beta thalassaemia heterozygotes have been determined by restriction endonuclease analysis to identify those with interacting alpha thalassaemia genes. A comparison of the haematological and haemoglobin synthesis findings of individuals with normal alpha genotypes (alpha alpha/alpha alpha) with those with one (-alpha/alpha alpha) or two (-alpha/-alpha) alpha genes deleted shows that the latter two groups have more balanced globin chain synthesis ratios, higher haemoglobin levels, and larger, better haemoglobinized red cells. This suggests that the degree of globin chain imbalance is a significant factor in determining the red cell characteristics in heterozygous beta thalassaemia. Screening programmes for thalassaemia, based on the detection of low MCVs, could miss cases of the interaction of alpha and beta thalassaemia.

Chromosome Mapping↗
PubMed1982

Delta beta (F)-thalassaemia in Sardinia.

A population survey carried out in southern sardinia on more than 5000 people has shown that delta beta (F)-thalassaemia, with a gene frequency of 0-00088, is a rare trait in this population. We examined the members of three families segregating for both delta beta- and beta(0)-thalassemia and a number of delta beta carriers identified during the screening. The doubly heterozygous children suffer from a mild form of Cooley's disease with non-alpha/alpha biosynthetic ratios within the range of values observed in beta (0)-thalassaemia homozygotes. Three of them have been transfusion dependent for some time. The delta beta carriers, although in many respects showing the usual picture of delta beta-thalassaemia, such as abnormal red cell indices, normal Hb A2, Hb F heterogeneously distributed in the erythrocytes, and low beta/alpha synthetic ratios, have unusually high levels of Hb F (range 10 to 20%) and particularly low glycine content (range 0.02 to 0.14 residues) in the isolated gamma CB3 peptide. These results have led us to the conclusion that the delta beta-thalassaemia found in Sardinia is different from the similar kind of delta beta defect found in Negroes and in other Mediterranean populations, including continental Italians.

Adolescent↗
PubMed1981

Beta-Thalassaemia types in southern Sardinia.

In this study the prevalence of the different beta-thalassaemia types in southern Sardinia was investigated by cellulose acetate and agar gel electrophoresis or globin chain synthesis analysis on column chromatography or both in (1) all the patients (347) presenting with thalassaemia major or intermedia at our haematology service from 1976 to 1979, and (2) a group of 82 patients with transfusion-dependent thalassaemia major randomly chosen from 236 under our care. Apart from six subjects with delta(beta)0/beta+-thalassaemia genotype and eight with beta0/beta+ or less probably beta+/beta/-thalassaemia, all thalassaemia major and intermedia patients studied were beta0-thalassaemia homozygotes. Globin chain synthesis on peripheral blood cells from these patients, performed at different intervals from blood transfusion, showed no incorporation of radioactive leucine into beta-globin peak, the same as before the transfusion. No correlation between kappa/gamma ratios and clinical severity or hypersplenism was found. Globin chain synthesis analysis carried out at birth in three infants later found to have homozygous beta0-thalassaemia demonstrated imbalanced or borderline kappa/gamma ratios.

Blood Transfusion↗
PubMed1981

Chronic liver disease in transfusion-dependent thalassemia: liver iron quantitation and distribution.

The quantitative and/or qualitative distribution of liver iron was assessed in 81 transfusion-dependent thalassemia major patients with chronic liver disease (36 with chronic active hepatitis, 23 with chronic persistent hepatitis, 22 with siderosis). Viral marker studies showed only 3 cases with both HBsAg and anti-HBc positivity in the serum, while the others had anti-HBc and anti-HBs or only anti-HBs or no B viral markers. A significantly higher iron overload was found in chronic hepatitis, particularly chronic active hepatitis, than in siderosis. The increased iron overload may be due to less intensive chelation treatment, higher intestinal absorption secondary to lower mean Hb levels, and/or to liver inflammation-dependent iron deposition. The liver iron overload in turn amy facilitate the development or persistence of chronic progressive liver disease.

Adolescent↗
PubMed1981

Prevention of homozygous beta-thalassemia by carrier screening and prenatal diagnosis in Sardinia.

We report here results of a 3-year pilot voluntary screening program coupled with prenatal diagnosis directed to the prospective prevention of homozygous beta-thalassemia (beta-thal) in Sardinia. The screening program took two approaches: outreach community testing and hospital testing on request after a period of sensibilization. The outreach testing was very effective as, taking into account the already known number of couples at risk with an affected proband (20), 74% of the couple at risk expected (61) on the basis of the carrier rate were identified. Less effective was the hospital testing in which half of the couples at risk expected were detected (502 with the 199 without an affected proband). After nondirective genetic counseling, approximately 85% of the couples at risk, which had a pregnancy, with no statistically significant difference between those with and those without a proband, requested prenatal testing. This figure showed a steadily increase from the beginning in 1977 to 1980. All the pregnancies (42), but two carrying homozygous fetuses, were terminated on parental request. A continuous hospital survey of thal-major admissions in the different hospitals of the counties showed a steady decline in the incidence figure at birth from 1976 (1:213) to 1978 (1:290). These results showed that even in a medium-developed, rural, Catholic population screening coupled with prenatal diagnosis can be successful in the control of a fatal, recessively inherited disorder.

Adult↗
PubMed1981

Clinical presentation of thalassemia major due to homozygous beta (0)-thalassemia.

This study concerns the clinical presentation of all thalassemia major or intermedia in children admitted to out genetics department from January 1978 to December 1979. At electrophoresis and/or globin chain synthesis analysis on column chromatography. All these patients were shown to have homozygous beta(0)-thalassemia. The clinical severity was highly variable, dependent on age at presentation and when the patient first became dependent on transfusions. On the main reasons for this variability may be associated with thalassemia 1 or alpha-thalassemia 2 which have an incidence figure of 13 % in our population and hence also in these patients. Remarkable findings of the clinical and hematological picture were: (a) early spleen enlargement and growth deficiency; (b) MCV and MCH values intermediate between normals and beta-thalassemia heterozygotes; (c) normal mean hemoglobin A2 percentage and corpuscular concentration; (d) frequently increased transferrin saturation and ferritin levels; (e) presentation at age greater than 2 with hemoglobin levels about 9 g/dl usually associated with a milder course.

Adolescent↗