摘要目的 对1例21号环状染色体[r(21)]嵌合体的不孕女性进行分析,探讨r(21)的临床表型和遗传特征.方法 综合应用染色体G显带、C显带、荧光原位杂交以及SNP微阵列芯片技术对患者的环状染色体进行识别和定位.结果 患者的核型为mos 46,XX,r(21)[166]/46,XX,der(21) [60]/45,XX,一21[20]/46,XX,dic r(21)[4].ish del(21) (q22.2?)(21qter-,AML1+,D21S259/D21S341/D21S342+).arr21q22.3(43,457,934-48,093,361)×1,21q22.2q22.3(40,218,429-43,457,934)×1-2.其父母核型正常.结论 r(21)综合征的临床表现取决于环状染色体的比例以及缺失片段的大小.该女性生殖器统的发育异常及月经改变可能与21q22.2远端片段的缺失有关.

abstractsObjective To investigate clinical phenotype and genetic characteristics of a 30-year-old infertile female carrying a mosaic ring 21 chromosome.Methods A combination of techniques including G-banding,C-banding,fluorescence in situ hybridization (FISH) and SNP array were performed to investigate the breaking point of the r(21).Results The karyotype of the patient was mos 46,XX,r(21)[166]/46,XX,der(21)[60]/45,XX,-21[20]/46,XX,dic r(21)[4].ish del(21) (q22.2?) (21qter-,AML1 +,D21S259/D21S341/D21S342+).arr 21q22.3(43,457,934 48,093,361) × 1,21q22.2q22.3 (40,218,429-43,457,934) × 1-2.The karyotypes of her parents were both normal.Conclusion Clinical phenotypes of patients carrying a ring 21 mainly depends on the percentage of abnormal cells and the deleted chromosomal fragment.The small uterus and oligomenorrhea in our patient may be attributed to the mosaic ring 21 chromosome.