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Biomedical subjects

R Galanello

Publications and source records attributed to R Galanello.

At least 127 records · Page 7Linked to original sources

Globin chain synthesis analysis in obligate beta 0-thalassemia heterozygotes with isolated increase of hemoglobin A2 levels.

Globin chain synthesis analysis was carried out in 14 obligate beta 0-thalassemia heterozygotes, i.e., parents of children with thalassemia major or intermedia due to homozygous beta 0-thalassemia, with almost normal red blood cell indices and isolated increase of Hb A2 levels. alpha/beta globin chain synthesis ratios were almost balanced or slightly reduced (0.62-1.30). This finding suggests that these heterozygotes carry both alpha- and beta-thalassemia genes. However, alpha-globin structural gene mapping by restriction enzyme analysis must be carried out to confirm this explanation.

Female↗

Interaction between the glucose-6-phosphate dehydrogenase deficiency and thalassaemia genes at phenotype level.

No significant differences were observed in the mean values of Hb A2 levels and red cell indices between G6PD- and G6PD+ beta thalassaemia carriers apart from the MCV, which was significantly higher in beta thalassaemia G6PD- subjects, but still in the thalassaemia carrier range. No difference was seen between G6PD+ and G6PD- alpha thalassaemia carriers. G6PD+ beta thalassaemia carriers show a significant increase in G6PD levels expressed as activity per g of Hb and to lesser extent as activity per number of red cells x 10(9); in G6PD+ alpha thalassaemia carriers this increase is statistically significant only when the enzyme levels are expressed as activity per g of Hb. G6PD- beta thalassaemia carriers had enzyme levels higher than non-thalassaemic G6PD- subjects only when the activity is expressed per g of Hb. G6PD activity was found to be increased in G6PD+ and G6PD- Hb H disease patients.

Erythrocyte Count↗

Haematological characteristics of the beta 0 thalassaemia trait in Sardinian children.

We report red cell indices and haemoglobin (Hb)A2 levels in Sardinian children with heterozygous beta 0-thalassaemia and in normal controls aged 6 months to 12 years. Iron-deficient children and those with haematological findings indicative of alpha-thalassaemia were excluded. As in adult carriers, these subjects have significantly increased mean red cell counts and significantly reduced mean Hb levels, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), haematocrit, and mean corpuscular haemoglobin concentration. From 66 to 76% of the heterozygous beta 0 thalassaemia children examined were anaemic. MCH and MCV were within the normal range in 2.8% of these children. Serum ferritin levels showed no difference from those of normal controls.

Child↗

alpha-Thalassaemia in Sardinian infants.

A haemoglobin survey carried out in southern Sardinian newborn infants showed an overall incidence of 12.9% with haemoglobin Bart's of more than 1%. The distribution was trimodal: low (1 to 2%), intermediate (2 to 10%), and high (about 25%). A considerable overlap was seen between the first two groups. Both the 1 to 2% and 2 to 10% groups had thalassaemia-like red cell indices at birth. Newborn infants ascertained as having alpha-thalassaemia at follow-up did not necessarily have unbalanced alpha/non-alpha chain synthesis at birth. At follow-up examination two subjects in the 25% group had developed haemoglobin H disease, and the 2 to 10% group had thalassaemia-like red cell indices and unbalanced globin chain synthesis ratios indicative of heterozygous alpha-thalassaemia. The 1 to 2% group either had normal or slightly reduced alpha-chain synthesis ratios, indicative of the silent alpha-thalassaemia carrier state. Two subjects with 2.0% and 2.5% haemoglobin Bart's at birth had heterozygous beta-thalassaemia at follow-up. Therefore, they were double heterozygotes for alpha- and beta-thalassaemia with alpha/beta-globin chain synthesis ratios of 0.81 and 0.86. Genotype assessment in a few families showed that infants with haemoglobin Bart's levels of more than 2% may have one of the genotypes --alpha/ --alpha or -- --/alpha alpha.

Female↗

Hematological characteristics of sardinian alpha-thalassemia carriers detected in a population study.

88 adults with thalassemia-like red cell indices, normal serum iron and normal hemoglobin (Hb) A2 and F levels, diagnosed in a mass screening had Hb H inclusion bodies studies (65 subjects) or Hb H inclusion bodies studies and globin chain synthesis analysis (23 subjects). The alpha/beta ratio of 0.70 +/- 0.10 was the same as in obligate alpha-thalassemia-1 (alpha-thal) carriers. Hb H inclusion bodies studies were found to be a reliable test for alpha-thal trait identification, resulting positive in approximately 70% of suspected carriers. The alpha-thal carrier defined by Hb H preparation or by globin chain synthesis had significant reduction in the mean Hb level, hematocrit, mean corpuscular hemoglobin and a significant increase in mean red cell count, but there was some overlap with controls.

Erythrocyte Count↗

Interaction of alpha and beta thalassaemia genes in two Sardinian families.

Our paper describes two Sardinian families with alpha-beta thalassaemia interaction. In the first (family S), the propositus, whose haemoglobin pattern at birth consisted of about 25% Hb Bart's and 75% Hb F, successively developed a clinical and haematological picture typical of Cooleys anaemia. Haematological and globin chain synthesis studies together with these findings suggest that he is homozygous for beta 0 thalassaemia and heterozygous for alpha thalassaemia-1 and alpha thalassaemia-2. This conclusion is further substantiated by the finding of various combination of alpha and beta thalassaemia among his family members. In the P family two twins whose haemoglobin pattern and synthesis data at birth were similar to those of the proband of family S died in the neonatal period. The mother was assumed to be a compound heterozygte for alpha thalassaemia-2 and beta 0 thalassaemia and the father for alpha thalassaemia-1 and beta 0 thalassaemia. The homozygous state for beta 0 thalassaemia in association with the alpha thalassaemia 1 and alpha thalassaemia 2 genes results in a severe clinical picture similar to that of a homozygous beta 0 thalassaemia. The interaction between the heterozygous state for beta 0 thalassaemia and the alpha thalassaemia 1 or alpha thalassaemia 2 genes, or the combination of both, results in a haematological picture similar to that of a beta thalassaemia heterozygote.

Adolescent↗

Beta 0 thalassemia trait in Sardinia.

The red cell indices and results of globin chain synthesis in peripheral blood of obligate beta 0 thalassemia (beta 0 thal) carriers (parents of homozygous beta 0 thal children) and beta thalassemia (beta thal) carriers identified during mass screening are reported. Red cell indices were similar in obligate beta 0 carriers and in carriers diagnosed during mass screening. However there was a higher incidence of anemia in female obligate beta 0 thal carriers. In Sardinia the beta 0 thal carrier showed the usual hematological characteristics of the high Hb A2 beta thal carrier with microcytosis, hypochromia, reduced osmotic fragility; Hb F greater than 1% was found in 30% of the carriers. With MCV, MCH, osmotic fragility test (OFT) and Shine and Lal discriminant function we found 3.5%, 1.5%, 3.5% and 4.0% respectively false negatives in carrier identification. A part from one subject, all obligate carriers had elevated Hb A2 levels. The alpha/beta ratio in obligate carriers (mean +/- SD) was 1.83 +/- 0.26 (N = 30).

Adolescent↗

Thalassaemia types and their incidence in Sardinia.

The frequency of thalassaemia syndromes in Sardinia was examined by a population survey. The data indicate that about 12.6% of the Sardinian subjects are carriers of beta-thalassaemia, while 6.9% of the population carries an alpha-thalassaemia gene, with a slight difference between the various provinces. These are among the highest frequencies of thalassaemia genes found in a Caucasian population today. A survey of hospital inpatients and outpatients showed a newborn incidence of homozygous beta-thalassaemia of 1 in 300. The reasons for the difference between the expected and observed incidence figures are discussed. Moreover, 3 subjects with deltabeta0-thalassaemia trait, 6 carriers of heterocellular persistence of fetal haemoglobin (HPFH), 1 sickle cell trait, and 3 subjects with Hb J Sardegna were found. Genetic heterogeneity of beta-thalassaemia syndromes in this population may generally result from interaction of alpha- and beta-thalassaemia genes.

Genes↗

Hemoglobin H disease in Sardinia: phenotypic and genetic observations.

In this study the clinical and hematological characteristics, the transmission pattern and the relative rates of globin chain synthesis were determined in the members of four Sardinian families with 14 patients affected by hemoglobin H disease. The severity of hemoglobin H disease in Sardinian subjects shows a high degree of variability. Clinically it usually appears intermediate between the hemoglobin H disease found in Oriental and Negro populations. The alpha/beta specific activity ratio was 0.42 +/- 0.10 indicating an analogous biochemical defect like that described in the Chinese. On the basis of hematological data and alpha/beta ratio, the genetics of hemoglobin H disease in Sardinians seem to follow a pattern similar to that observed in Orientals: one parent showing alpha-thalassemia-1 trait and the other alpha-thalassemia-2 trait. Parent offspring transmission of hemoglobin H disease did occur in 2 out of 6 hemoglobin H matings with spouses carrying the alpha-thalassemia-1 gene. This observation indicates either a high frequency of alpha-thalassemia trait in Sardinians or a high incidence of inbreeding. In one family the mating of a patient with hemoglobin H disease and a normal person produces 6/6 offspring with alpha-thalassemia-1. The genetic implications of this transmission pattern are discussed.

Adult↗

Quantitation of Hb a2 with DE-52 microchromatography in whole blood as screening test for beta-thalassemia heterozygotes.

HB A2 was assayed by means of DE-52 microchromatography in hemolysates from 285 normal subjects and 223 beta-thalassemia heterozygotes. No overlap was found between both groups. Comparable results were observed analyzing whole blood samples collected in capillary tubes from 550 normal subjects and 295 beta-thalassemia heterozygotes. Our results demonstrate that this technique is useful in a screening program for beta-thalassemia trait.

Adult↗

Prenatal diagnosis of inherited hemoglobinopathies.

This paper reviews the methodology available to make prenatal diagnosis of inherited hemoglobinopathies by DNA analysis and the strategy to be used for the large scale application of this procedure to high-risk populations. The most straightforward approach for prenatal diagnosis is nowadays based on the analysis of DNA enzymatically amplified by the polymerase chain reaction (PCR). The mutations, produced by gross structural rearrangement of the DNA and those affecting a restriction recognition site, are directly detected by visualization following ethidium bromide staining of the electrophoretic pattern resulting from enzymatic digestion of amplified DNA. The remaining ones are detected by dot blot analysis with allelic specific oligonucleotide probes. Because in each population a limited number of specific beta-thalassemia mutations are prevalent, prenatal diagnosis by DNA analysis may be carried out by a population-specific strategy based on the amplification of those regions of the beta-globin genes containing the mutations most frequently occurring in each population followed by dot blot analysis with allelic specific oligonucleotide probes. This approach has the great advantage of being very simple, because radioactive probes are not necessary, very rapid, the results being obtained within 24 hours from sampling and very sensitive, only a limited amount of DNA in the order of 50 ng being necessary.

Chromosome Mapping↗

Globin chain synthesis analysis by high performance liquid chromatography in the screening of thalassemia syndromes.

We applied reversed phase high performance liquid chromatography for globin chain synthesis analysis in screening for beta-thalassemia. The alpha/non-alpha-globin chain synthesis ratios have been determined in alpha-, beta-, and deltabeta-thalassemia carriers using the classical carboxymethyl cellulose chromatography as the reference method. Reversed phase high performance liquid chromatography is fast, accurate, and reproducible, and may be a suitable alternative for the traditional carboxymethyl cellulose chromatography.

Carboxymethylcellulose Sodium↗

Hemoglobin Sabine [beta 91 (F7) Leu-->Pro]: occurrence in a Sardinian individual with hemolytic anemia and inclusion bodies.

BACKGROUND: Hemoglobin (Hb) Sabine (beta 91 Leu-->Pro) is an unstable variant detected for the first time in a 16-year-old Scottish-English-German girl affected by moderately severe hemolytic anemia. A second case was described in a patient of Yugoslavian descent. We report another case of this Hb variant arising as a de novo mutation in a Sardinian patient. METHODS: Definition of the mutation was obtained by DNA direct sequencing on amplified beta-globin gene, as well as by structural analysis of the hemoglobin variant. RESULTS AND CONCLUSION: The patient presented a moderately severe hemolytic anemia with red blood cell inclusion bodies. Hemoglobin electrophoresis showed that quantitatively the abnormal fraction represented 9% of the total Hb amount. beta globin gene analysis revealed a single nucleotide substitution, T-->C, at codon 91, which gives rise to a leucine-->proline substitution. Structural analysis of the variant confirmed the amino acid substitution (Leu-->Pro) predicted by DNA sequencing.

Adult↗

Iron stores and iron deficiency anemia in children heterozygous for beta-thalassemia.

This paper describes the status of iron stores, the incidence and the hematological characteristics of iron deficiency anemia in children heterozygous for beta-thalassemia. In beta-thalassemia heterozygotes, iron stores were similar to the controls in infancy and tended to increase with age, reaching levels of moderate iron overload solely in adult males. Iron deficiency anemia occurred less frequently in children heterozygous for beta-thalassemia as compared to normal controls, while no difference between the two groups was observed in the incidence of iron deficiency. Ineffective erythropoiesis, typical of heterozygous beta-thalassemia, by causing an increase of iron absorption may limit the effect of iron shortage. At similar levels of iron depletion, however, children heterozygous for beta-thalassemia develop a more severe anemia as compared to non beta-thalassemic children. With the exception of two children, HbA2 levels in the presence of iron deficiency anemia remain in the range of heterozygous beta-thalassemia. In conclusion, our results indicate that children heterozygous for beta-thalassemia have normal iron stores but are relatively protected against the development of iron deficiency. When iron deficiency anemia develops, its clinical expression is usually more severe than in non beta-thalassemic children.

Anemia, Hypochromic↗

Preliminary experience with the differential pH technique for glucose-6-phosphate dehydrogenase (G6PD) measurement in whole blood: application to an area with high prevalence of thalassaemia and G6PD deficiency.

A new differential pH technique for glucose-6-phosphate dehydrogenase quantitative determination in whole blood has been evaluated. It is a rapid (90 s/analysis), reproducible (C.V. within-run 3.7%; between-run: 2.8%) and accurate method (in comparison with WHO method: r = 0.970). Reference intervals in non-deficient males were evaluated in 167 non-thalassaemics and in 60 beta-thal heterozygotes. The G6PD activity in beta-thalassaemia carriers is higher than in normals; this is particularly true if the activity is expressed in terms of U/g Hb. The phenotypic distribution measured in females is in agreement with that calculated by the Hardy-Weinberg law based on the incidence of the Gd(-) gene in males.

Adolescent↗