Chromosomal abnormalities are the most frequent genetic disorders observed in live births and miscarriages. Trisomies 21, 18, and 13 are the most frequently observed aneuploidy conditions among them. The biologic mechanism of this phenomenon remains unknown. Apolipoprotein E and its alleles have become the focus of the investigations lately. In this review the authors combined the available data from the literature and compared those results with their own observations. Their results based on determination of apo E alleles by PCR-RFLP method from DNA samples combined from trisomic conceptuses and healthy blood donors in the same population. They did not find significant difference in the distribution of apo E alleles, like it was published in several other author's works. The authors discuss the available theories for the development of trisomic conditions and call the attention for the theory of mtDNA mutations as the possible factor.