Bimodal distribution of erythrocytes in heterozygotes for strong Mediterranean glucose-6-phosphate dehydrogenase deficiency.

Content Provider	Semantic Scholar
Author	Sartori, Enrico Panizon, Franco Zacchello, Franco
Copyright Year	1966
Abstract	Haemolytic favism is a condition that affects children predominantly, and is frequent in Sardinia and in other Mediterranean areas. It is related to a deficiency of the enzyme glucose-6-phosphate dehydrogenase (G6PD) in the erythrocytes, as is 'primaquine sensitivity' of American Negroes (Larizza, Brunetti, Grignani, and Ventura, I958; Siniscalco, Motulsky, Latte, and Bernini, ig60; Carson, Flanagan, Ickes, and Alving, I956; Gross, Hurwitz, and Marks, I958; Tarlov, Brewer, Carson, and Alving, i962). In both conditions the deficiency is due to a mutant allele of an X-linked gene, but in haemolytic favism the enzyme is of an electrophoretically slow (B) type, while in primaquine sensitivity it is of a fast (A) type. The deficiency is definitely more pronounced in haemolytic favism, but recently a mild deficiency of the B type has been found in Greece (Kirkman, I962; Kirkman, Schettini, and Pickard, I964; Porter, Boyer, Watson-Williams, Adam, Szeinberg, and Siniscalco, I964; Stamatoyannopoulos, Panayotopoulos, and Papayannopoulou, I964). In spite of the different dose of X-linked alleles, hemizygous males and homozygous females, both normal and mutant, do not differ in their mean G6PD enzyme levels (Adinolfi, Bernini, Carcassi, Latte, Motulsky, and Siniscalco, I960; Davidson, Childs, and Siniscalco, I964) nor are there dosage differences among individuals with abnormal numbers of sex chromosomes, such as XO, XXY, XXX, XXXY, XXXX (Grumbach, Marks, and Morishima, I962; Harris, Hopkinson, Spencer, Court Brown, and Mantle, I963). In both the American and Mediterranean deficiencies, heterozygous females present enzyme levels that are intermediate between but also overlap with those of normal and of mutant hemizygous males (Beutler, Yeh, and Fairbanks, I962; Adinolfi, Davidson, Latte, Meera Khan, Piomelli, Ratazzi, and Siniscalco, I963; Davidson et al., I964). Moreover, Sardinian females clinically affected with haemolytic favism are observed with a frequency that is higher than the number of homozygotes and lower than the number of heterozygotes expected on the basis of the local gene frequencies (E. Sartori, unpublished data). These discrepancies could be explained by the Lyon hypothesis (I962) which postulates that one of the two X chromosomes of normal females is genetically inactive and that either of the two X chromosomes may be inactivated in early embryonic life at random in different cells of the same individual.
File Format	PDF HTM / HTML
DOI	10.1136/jmg.3.1.42
PubMed reference number	5911829
Journal	Medline
Volume Number	3
Issue Number	1
Alternate Webpage(s)	http://jmg.bmj.com/content/jmedgenet/3/1/42.full.pdf
Alternate Webpage(s)	https://doi.org/10.1136/jmg.3.1.42
Journal	Journal of medical genetics
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article