The Progress of Research on Genetic Factors of Recurrent Pregnancy Loss

Figure 1

(a) Balanced translocations on nonhomologous chromosomes. (b) Possible gametes in patients with balanced translocations. During meiosis I, the translocated chromosome combines with its normal homologous chromosome to form a tetrad. Balanced gametes containing normal non-homologous chromosomes or two translocated chromosomes resulting from alternate segregation are designated by green border, and unbalanced gametes by red border. Chromosome segregation patterns for tetrad are shown: 2 : 2 (two non-homologous or two homologous chromosomes segregate together in an adjacent-1 or adjacent-2 segregation, respectively), 3 : 1 (three chromosomes segregate into one cell and one into the other), and 4 : 0 (all chromosomes segregate together).

(a)

(b)