trisomy 21 was observed in every aneuploid stem cell line and , in one case , trisomy 21 was maintained in the bone marrow leukemic cells but not in the orbital rhabdomyosarcoma cells , indicating that this constitutional chromosomal aberration is probably crucial for and predisposed to the development of acute leukemia in ds patients .
C0008625
chromosomal aberration
C0013080
ds