4-三体大约占自然流产的1％,它可能来源于减数分裂或体细胞。4-三体嵌合体非常罕见。单亲二体(UPD)是指从父母一方遗传了一对同源染色体,除此以外个体的染色体正常。一个三体的胚胎可通过丢失一条染色体而恢复成双倍体,1/3矫正的三体可通过这种三体解救成为单亲二体。本文报道了2例4-三体嵌合体的病例,其中1例在胎儿组织中发现了4号染色体的单亲二体。 Trisomy 3 accounts for about 1% of spontaneous abortion, it may be derived from meiosis or somatic cells. 4-trisomy chimera is very rare. Single-parent two-body (UPD) means that a pair of homologous chromosomes is inherited from one parent and the chromosomes of the other individuals are normal. A three-body embryo can be recovered as a diploid by losing one chromosome, and one third of the corrected three bodies can be rescued by the trisomy as a single parent. In this paper, we report the cases of 4-trisomy in two cases, of which one fetus was found on chromosome 4 in one fetus.