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G Filippi

Publications and source records attributed to G Filippi.

At least 73 records · Page 4Linked to original sources

Variability of red cell phenotypes between and within individuals in an unbiased sample of 77 heterozygotes for G6PD deficiency in Sardinia.

The distribution of G6PD red blood phenotypes in an unbiased sample of 77 Sardinian certain heterozygotes for the GdMediterranean mutant was found to be skewed in favor of the G6PD (+) cells. Four of these individuals exhibited the normal hemizygous phenotype in all of their cells, but two of them had a mosaic population of G6PD (+) and (-) red blood cells when reexamined after 1 year. These findings suggest that somatic selection may be the main factor determining the phenotype variability of individual somatic cells in highly differentiated tissues of heterozygotes at the G6PD locozygotes for the GdMediterranean mutant should not be used as a criterion for precise estimation of the embryonic or stem tissue cell pool at X inactivation.

Erythrocytes↗

Hair root versus red cell individual phenotype in Sardinian heterozygotes for G6PD deficiency (Mediterranean type).

G6PD activity was assayed in 20 Sardinian heterozygotes for G6PD deficiency and related to that of LDH and MDH. One of these heterozygotes showed a deficient phenotype in all her follicles, while the remaining 19 had different proportions of deficient, intermediate, and normal follicles. This is in accordance with a previous estimate. Because of the broad fiducial limits at the 5% level and because of some developmental considerations, this value cannot be interpreted as indicative of the number of primordial cells for scalp epidermis at the time of X-chromosome inactivation, as previously stated. The assay of single hair follicles is, however, a very valuable tool for establishing the role of cell selection in the same or in a different tissue, like peripheral blood.

Erythrocytes↗

Population genetics of haemoglobin variants, thalassaemia and glucose-6-phosphate dehydrogenase deficiency, with particular reference to the malaria hypothesis.

The authors report data on the genetic distribution of thalassaemia and of glucose-6-phosphate dehydrogenase deficiency in the populations of certain Sardinian villages, many of which are not only of great antiquity but have maintained isolation for very long periods and therefore possess the following three requirements for suitability for investigation of the possible interrelationships among malaria, thalassaemia and G-6-PD deficiency: a reasonable degree of ethnic homogeneity, availability of reliable demographic data, and availability of malaria-free populations of adequate size and of ethnic background and genetic isolation similar to those of the malarial populations.Investigations including more than 6000 observations in 52 villages demonstrated a positive correlation between the incidences of thalassaemia and G-6-PD deficiency. It is suggested that the genotype that carries thalassaemia and/or the enzyme deficiency may have a high adaptive value in a malarial environment.It is concluded that there is a need further to investigate human genetic structure and the biological fitness of the principal genotype combinations in both existing environments and those that will result from continued cultural evolution.

Genetics, Population↗