Abstract:

Objective To investigate the strategies for the determination of uncle/aunt-niece relationship through the detection of autosomal and X-chromosomal STR （X-STR） loci. Method Genomic DNAs were extracted from blood stain samples of 4 persons. 39 autosomal STR loci were genotyped by Goldeneye 20A and AGCU 21+1 kit， and 24 X-STR loci were genotyped by Biotype Argus X-12 kit and 16 plex in-house system. Results Relationship between the detected uncle/aunt and niece were not excluded based on the results of autosomal STR genotyping and paternity index. The X-STR genotyping result was consistent with the present conclusion. Conclusion X-STR is a good supplement to autosomal STR. It is reliable to adopt the genotyping results of both genetic markers when determining the relationship between uncle/aunt and niece.

Key words: forensic genetics, genetic marker, STR, X-STR

摘要：

目的 通过对常染色体STR和X染色体STR基因座进行分型检验，探讨姑侄、叔侄关系的鉴定策略。方法 提取案例中被检女孩和另外3名个体（女性2名，疑为被检女孩的姑姑；男性1名，疑为被检女孩的叔父）的血样DNA，采用Goldeneye 20A系统和AGCU 21+1 系统分别进行常染色体STR基因座的复合PCR扩增，用Mentype○R Argus X-12试剂盒和本室自主研制的16重X染色体STR 扩增体系分别进行X染色体STR基因座的复合PCR扩增，用3130 XL遗传分析仪进行毛细管电泳和基因型分析。结果 依据常染色体STR 基因型结果及姑侄、叔侄关系指数计算结果，不排除2名被检姑姑和与被检女性存在姑侄关系；不排除被检叔叔和与被检女性存在叔侄关系，X染色体STR分型结果支持此鉴定意见。结论 对于姑侄、叔侄关系鉴定案例，X染色体STR基因座是常染色体STR基因座的良好补充，两者联合运用可获得可靠的鉴定意见。

关键词: 法医遗传学, 遗传标记, STR, X-STR