Cat-eye syndrome, a partial trisomy 22.

Abstract

A family is presented in which a phenotypically normal mother and her healthy daughter both had abnormal children with a small supernumerary chromosome. Both had clinical symptoms suggestive of cat-eye syndrome. In both women 1 G-chromosome was found to be replaced by a small submetacentric satellited chromosome. Its fluorescence pattern was compatible with that of a chromosome 22, and so was the fluorescence pattern of the supernumerary chromosome in one of the phenotypically abnormal children. Since complete monosomy G in addition to partial autosomal trisomy would not be compatible with clinical “normality” the respective karyotypes must be interpreted as a small deletion of a chromosome 22 in the healthy mother and daughter and a partial trisomy 22 in their abnormal children. Therefore it can be concluded that a deletion of a chromosome 22 is compatible with a normal phenotype and that the cat-eye syndrome results, at least in this family, from a partial trisomy 22.