G6PD haplotypes spanning Xq28 from F8C to red/green color vision
- Instituto Internazionale di Genetica e Biofisica, Naples (Italy)
- Instituto per lo Studio delle Malattie Ereditarie e Carenziali, Cosenza (Italy)
- Instituto per lo Studio delle Malattie Ereditarie e Carenziali, Cosenza (Italy) Hammersmith Hospital, London (United Kingdom)
- Hammersmith Hospital, London (United Kingdom)
The most telomeric region of the human X chromosome within band Xq28 consists of a gene-rich region of about 3 Mb which contains the genes for coagulation factor VIIIc, glucose-6-phosphate dehydrogenase (G6PD), and red/green color vision. The authors have studied five polymorphic sites from this region, in a sample of normal people from the Cosenza province of Southern Italy. These sites, which span a distance of some 350 kb, are in strong linkage disequilibrium. Of the 32 possible haplotypes only 10 were found, and 4 of these account for 80% of all X chromosomes analyzed. In addition, they found that all G6PD-deficient people with the G6PD Mediterranean mutation belong to only two haplotypes. One of these (Med 1) is found only within a small subregion of the area investigated, west of the Appennine mountain range. Most remarkably, all Med 1 G6PD-deficient individuals also had red/green color blindness. The more frequent haplotype (Med 2) is the same in Calabria and in Sardinia, where it accounts for about 90% of the G6PD Mediterranean mutations, despite the fact that gene flow between the populations of Sardinia and Southern Italy must have been limited. These data do not enable determination of whether the two types of G6PD Mediterranean have arisen through two separate identical mutational events or through a single mutational event followed by recombination. However, the data indicate relatively little recombination over an extended region of the X chromosome and they suggest that the G6PD Mediterranean mutation is recent by comparison to the other polymorphisms investigated. 44 refs., 4 figs., 5 tabs.
- OSTI ID:
- 7225786
- Journal Information:
- Genomics; (United States), Vol. 17:1; ISSN 0888-7543
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HUMAN X CHROMOSOME
GENETIC MAPPING
OXIDOREDUCTASES
GENES
BLOOD COAGULATION FACTORS
SENSE ORGANS DISEASES
CHROMOSOMES
COAGULANTS
DISEASES
DRUGS
ENZYMES
HEMATOLOGIC AGENTS
HETEROCHROMOSOMES
HUMAN CHROMOSOMES
MAPPING
ORGANIC COMPOUNDS
PROTEINS
X CHROMOSOME
550400* - Genetics