Idiopathic thrombocytopenic purpura (ITP) Idiopathic thrombocytopenic purpura (ITP) is a bleeding disorder in which the immune system destroys platelets, which are necessary for normal blood clotting. People with the disease have too few platelets in the blood. ITP is sometimes called immune thrombocytopenic purpura or simply, immune thrombocytopenia.
sex-linked disorder - any disease or abnormality that is determined by the sex hormones; hemophilia is determined by a gene defect on an X chromosome. bleeder's disease, haemophilia, hemophilia - congenital tendency to uncontrolled bleeding; usually affects males and is transmitted from mother to son.
sex-linked. referring to a pattern of inheritance characteristic of genes located on one type of sex chromosome (for example X) and not found on the other type (for example Y); in mammals, in almost all cases, the gene controlling the trait is on the X chromosome so this pattern is often called X-linked.