H00994 | |
H number | H00994 |
Name | Familial skewed X-chromosome inactivation |
Description | X chromosome inactivation is the transcriptional silencing of the majority of genes on one of the two X chromosomes in mammalian females that equalizes the effective dosage of X-linked genes between XX females and XY males. Therefore mammalian females are mosaics for two cell populations with different X chromosomes active. Skewed X inactivation is defined as a pattern where the cells show a preferential inactivation of one X chromosome. The incidence of skewing is shown to be age dependent but in general, skewing does not have any biologic consequence. However, in cases of individuals with nonlethal mutated allele, degree of skewing is predisposing to genetic diseases such as hemophilia A. The key player is the X inactivation-specific transcript (XIST), an X-linked untranslated RNA that coats the inactive X-chromosome. |
Category | Chromosomal abnormality |
Network | - |
Gene | - |
Pathogen | - |
Env factor | - |
Carcinogen | - |
Drug | - |
Comment | Hemophilia A is described in H00219. XIST [HSA:7503] |
Other DBs | ICD-11: LD51 MeSH: D049951 OMIM: 300087 |
Reference | PMID:19396465 AUTHORS Orstavik KH TITLE X chromosome inactivation in clinical practice. JOURNAL Hum Genet 126:363-73 (2009) DOI:10.1007/s00439-009-0670-5 PMID:16720461 AUTHORS Orstavik KH TITLE Skewed X inactivation in healthy individuals and in different diseases. JOURNAL Acta Paediatr Suppl 95:24-9 (2006) DOI:10.1080/08035320600618783 PMID:11110715 AUTHORS Cazzola M, May A, Bergamaschi G, Cerani P, Rosti V, Bishop DF TITLE Familial-skewed X-chromosome inactivation as a predisposing factor for late-onset X-linked sideroblastic anemia in carrier females. JOURNAL Blood 96:4363-5 (2000) PMID:12572852 AUTHORS Lyon MF TITLE X-chromosome inactivation and human genetic disease. JOURNAL Acta Paediatr Suppl 91:107-12 (2002) DOI:10.1111/j.1651-2227.2002.tb03120.x PMID:9585586 AUTHORS Migeon BR, Haisley-Royster C TITLE Familial skewed X inactivation and X-linked mutations: unbalanced X inactivation is a powerful means to ascertain X-linked genes that affect cell proliferation. JOURNAL Am J Hum Genet 62:1555-7; author reply 1557-8 (1998) DOI:10.1086/301858 |