Cytogenetic Studies in Twins, one with Chronic Granulocytic Leukaemia

CHROMOSOMAL investigations of a patient with chronic granulocytic leukaemia and his normal identical twin were reported by Goh and Swisher 1 . While some cells cultured from the peripheral blood of the patient contained the Philadelphia chromosome, those from the peripheral blood and the bone marrow of the normal twin did not show the abnormality. The authors comment on the extreme rarity of this finding; however, we now record a second example.