title: Improvement of pancytopenia and thrombocytopenia with decreasing mosaicism for isochromosome Xp.
abstract: We report the unique association of variable constitutional mosaicism 46,X, i(X)(p10)/46,XX with recurrent thrombocytopenia in a child with failure to thrive and apnea in infancy. Her bone marrow had equal distribution of the normal and abnormal cell lines at diagnosis, at nearly 6 years of age. Improvement of her pancytopenia and thrombocytopenia was concurrent with a decreasing level of mosaicism observed in multiple studies over the next 3 years. This suggests that extra copies of genes on the p-arm are inhibitory to blood cell maturation, with long-term selection against the i(Xp)-containing cells.
authors.affiliation: Department of Pathology and Laboratory Medicine, St. Christopher's Hospital for Children and Drexel University College of Medicine, Philadelphia, Pennsylvania 19134, USA.
authors.forename: S Lauren
authors.initials: SL
authors.lastname: Gray
authors.forename: J P
authors.initials: JP
authors.lastname: de Chadarévian
authors.forename: Carol E
authors.initials: CE
authors.lastname: Anderson
authors.forename: Frank E
authors.initials: FE
authors.lastname: Shafer
authors.forename: Hope H
authors.initials: HH
authors.lastname: Punnett
authors.forename: Jennifer J D
authors.initials: JJ
authors.lastname: Morrissette
mesh_terms: D002648:Child; D002675:Child, Preschool; D041321:Chromosomes, Human, X / Q000235:genetics*; D005260:Female; D006801:Humans; D018404:Isochromosomes / Q000235:genetics*; D007621:Karyotyping; D009030:Mosaicism; D010198:Pancytopenia / Q000150:complications* / Q000235:genetics*; D013921:Thrombocytopenia / Q000150:complications* / Q000235:genetics*