Broad Clinical Spectrum of Mosaic Trisomy 2: Report of Two New Cases in Tunisia

Mosaic trisomy 2 is the detection of two or more cells with the additional chromosome 2 distributed over two or more independent cultures.

We present 2 new cases of mosaic trisomy 2 detected at amniocentesis with previously unreported clinical features and we review the literature of the clinical manifestations of this uncommon aneuploidy.

Cytogenetic analysis of the amniotic fluid culture showed mosaic trisomy 2 (47,XY,+2[9]; 46,XY[19]) (32%) for case 1, and (47,XY,+2[13]; 46,XY[21]) (38%) for case 2 in two independent flask cultures. Our second case presented a new clinical finding non described previously in mosaic trisomy 2 which is occipital schizencephaly associated with hydrocephalus.

Two new cases of mosaic trisomy 2 were detected at amniocentesis with previously unreported clinical features. Prenatal diagnosis of chromosomal mosaic trisomy 2 continues to create a dilemma in genetic counseling because of limited data and variable outcomes.