MOSAIC VARIEGATED ANEUPLOIDY WITH MULTIPLE CONGENITAL-ABNORMALITIES -HOMOZYGOSITY FOR TOTAL PREMATURE CHROMATID SEPARATION TRAIT

Separation of chromatids of all mitotic chromosomes, here called total premature chromatid separation (total PCS), was observed in 67 to 87. 5% of repeated cultures of peripheral blood lymphocytes from two unrel ated infants. Also noted was a variety of mosaic aneuploidies, especia lly trisomies, double trisomies, and monosomies, to be called mosaic v ariegated aneuploidy. The infants both showed severe pre- and postnata l growth retardation, profound developmental retardation, uncontrollab le seizures, severe microcephaly, hypoplasia of the brain, Dandy-Walke r anomaly, abnormal facial appearance, and bilateral cataract. Patient 1, a girl, in addition had a cleft palate, multiple renal cysts, and Wilms tumor of the left kidney. Whereas patient 2, a boy, had ambiguou s external genitalia. They both died within 2 years of age. In the two families of the infants, their parents and three other members showed 2.5 to 47% lymphocytes with total PCS but without mosaic variegated a neuploidy or phenotypic abnormalities. Another 10 relatives studied sh owed 0 to 1% cells with total PCS and so were judged negative for the total PCS trait. It was deduced that the total PCS trait in the two fa milies was transmitted in an autosomal-dominant fashion, and the two a ffected infants were homozygous for the trait. (C) 1998 Wiley-Liss, In c.