Sexual development of patients with isochromosomes for the long arm of the X chromosome.
The sexual development of 14 girls with non-mosaic monocentric 46,X,iXq karyotype was studied. Seven out of eight girls were found to have immature secondary sexual characteristics and amenorrhoea, a finding greatly contrasting with that in Triplo-X girls. The relative ineffectiveness of the isochromosome Xq in maintaining fertility may be due to the absence of one short arm, which probably also carries a gonadal determinant. Alternatively, the presence of two inactivation sites on one isochromosome may render the gonadal determinants inactive at an important stage in gonadal development.
D000293:Adolescent; D000568:Amenorrhea / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D002874:Chromosome Mapping; D004303:Dosage Compensation, Genetic; D005260:Female; D005298:Fertility; D006801:Humans; D012730:Sex Chromosomes; D012732:Sex Determination Analysis; D012741:Sexual Maturation; D014960:X Chromosome