Autopsy findings of a 37-year-old man with a complex mosaic karyotype involving del(18p), monosomy 13, and trisomy 20.

We report on the autopsy findings of a 37-year-old man with a complex karyotype (mos46,XY,del(18)(p11.1)[14]/46,XY, -13, del (18)(p11.1), +20[8]/47,XY,del(18)(p11.1), +20[8]). He was known to be blind, non-ambulatory, have severe mental retardation, and a seizure disorder. External physical findings at the time of autopsy included micrognathia, short stubby fingers, and rocker bottom feet. Left lobe dominance of the liver and mislocation of the ileocecal junction and appendix were noted on internal examination. The brain was small (700 g) and poorly developed. Microscopically it showed an absence of neurons in the olivary and dentate nuclei, absence of Purkinje cells in the cerebellum, severe depletion of internal granular cells in the cerebellum, and cerebellar dysplasia. Fat infiltration was noted in an unusual distribution in several organs including a pattern in the heart consistent with arrythmogenic right ventricular dysplasia (ARVD). Findings of this mosaic chromosomal karyotype have not been previously described. This report will discuss this individuals physical findings and their relation to similar monochromosomal aberrations.