OBJECTIVE: Unexplained recurrent @entity2208 is a common @entity1 's health problem that affects approximately 1 of every 200 @entity1 who wish to have @entity1 . It has long been assumed that a large proportion of recurrent @entity2208 results from genetic problems, but no causative genes have been identified to date. Here, we tested the hypothesis that a subset of @entity1 with recurrent @entity2208 are carriers of @entity1112 that result in the loss of male pregnancies. STUDY DESIGN: X chromosome inactivation patterns, an assay used to detect @entity1 who are likely to be carriers of @entity1112 , were compared between 105 female @entity1 with @entity393 and 101 @entity1 (control subjects) with a single successful pregnancy and no history of @entity393 . Inheritance patterns and gender of offspring were studied in relevant subsets of @entity1 . RESULTS: Female @entity1 showed a highly statistically significant increase in the frequency of skewed X chromosome inactivation (90%; P < .0005). Female @entity1 with highly skewed X chromosome inactivation showed a significant decrease in male @entity1 . Four of 6 families that were studied showed maternal inheritance of the skewed inactivation trait. CONCLUSION: We found the 14% of @entity1 with unexplained recurrent @entity393 show highly skewed X inactivation, which suggests that they are carriers of @entity1112 . Furthermore, the observed gender bias among @entity1 with highly skewed X inactivation suggests selective loss of male conceptions, which is consistent with an @entity1112 that leads to cell death or growth disadvantage. Identification of such female carriers is important for the reproductive counseling and treatment of these @entity1 .

A novel X chromosome-linked genetic cause of recurrent XXXX .

@entity1 :: ('9606', 'Species') :: ['participants', 'women', 'children', 'patients'] @entity2208 :: ('MESH:D000022', 'Disease') :: ['spontaneous abortion'] @entity1112 :: ('MESH:D040181', 'Disease') :: ['X-linked recessive disorders', 'X chromosome-linked genetic defect', 'X-linked recessive cell-lethal traits', 'X-linked recessive lethal traits'] @entity393 :: ('MESH:D034381', 'Disease') :: ['pregnancy loss', 'idiopathic recurrent pregnancy loss']
@entity2208 :: (MESH:D000022,Disease) :: ['spontaneous abortion']
