PT  - JOURNAL ARTICLE
AU  - Howell, R T
AU  - Roberts, S H
AU  - Beard, R J
TI  - Dicentric X isochromosomes in man.
AID  - 10.1136/jmg.13.6.496
DP  - 1976 Dec 01
TA  - Journal of Medical Genetics
PG  - 496--500
VI  - 13
IP  - 6
4099  - http://jmg.bmj.com/content/13/6/496.short
4100  - http://jmg.bmj.com/content/13/6/496.full
SO  - J Med Genet1976 Dec 01; 13
AB  - Four cases of Turner's syndrome are presented in which an apparent X isochromosome i(Xq) has been found to possess two regions of centromeric heterochromatin. It is suggested that these chromosomes were isodicentric structures capable of functioning as monocentric elements as a result of the inactivation of one centromere. The prevalence of mosaicism is believed to be a consequence of the dicentric nature of these chromosomes, and it is considered possible that a high proportion of X isochromosmes are structurally dicentric. Banding patterns showed that the exchange site involved in the formation of the dicentric chromosome was different in at least three of the cases.