Christmas factor: dosage compensation and the production of blood coagulation factor IX.
The amount of factor IX (Christmas factor) for different genotypic classes was determined by means of a variant of the thromboplastin generation test. The mean value for females heterozygous for the Christmas gene was about half the mean values for normal males and for normal homozygous females; means for the latter two groups were about equal. This dosage compensation is interpreted as evidence in support of Lyon's hypothesis, according to which one X chromosome is inactive in mammalian females.
D000818:Animals; D004303:Dosage Compensation, Genetic; D005164:Factor IX; D005260:Female; D006579:Heterozygote; D006801:Humans; D008297:Male; D014960:X Chromosome
D005164:Factor IX
FACTOR IX