J Med Genet 1999;36:865-866
( November )
Letters to the editor
Skewed
X chromosome inactivation in a female with haemophilia B and in her
non-carrier daughter: a genetic influence
on X chromosome inactivation?
| The first 150 words of the full text of this article appear below. |
EDITOR
Phenotypic expression of X linked
disorders in females may be the result of an X chromosome anomaly or
homozygosity for the mutated gene, but is probably most frequently the
result of skewed X chromosome inactivation. Skewed X inactivation may be the result of a chance event, but may also be because of genetic factors.1 We report here the results of X inactivation
analysis in a family with haemophilia B, which showed extremely skewed X inactivation both in a female haemophilia patient and in her non-carrier daughter, indicating a possible genetic influence on X
chromosome inactivation in this family. Familial skewed X inactivation
may interfere with carrier detection, since skewed X inactivation with
the mutant gene on the inactive X chromosome may lead to a normal
phenotype in a carrier.
The patient was a 40 year old female who belonged to a
family with moderate haemophilia B2 (fig 1). . . . [Full text of this article]
