Retinoblastoma and long arm deletion of chromosome 13. Attempts to define the deleted segment

Abstract

A girl with retinoblastoma, mild psychomotor retardation, bifid uvula and clinodactyly of the fifth fingers is described. A chromosome analysis revealed a long arm deletion of a D chromosome. An autoradiographic analysis, as well as G‐ and Q‐banding analyses indicated a 13q‐ chromosome. Measurements of length, surface and relative reflection of the different light and dark bands in the normal and abnormal chromosome 13 pointed to an interstitial deIetion, mainly of band q21 (46, XX, de1(13) (pter→q14:: q22→qter) The chromosome findings and the clinical features of the patient are discussed and compared with other reported cases.