一个RHD 270A等位基因家系研究

The family investigation of an RHD 270A allele carrier

目的 调查 Rh血型 D抗原基因 ( RHD gene,RHD)阳性、D抗原阴性等位基因的家系遗传。方法 根据 RHD2 70 A等位基因序列设计 1对特异性引物 ,建立序列特异性引物 -聚合酶链反应方法 ,检测了一个 RHD2 70 A等位基因先证者的 6名家系成员 ,同时采用限制性片段长度多态性方法鉴定了全部家庭成员的 RHD基因杂合型。结果 RHD2 70 A等位基因分别在先证者、其父亲和叔父中检出 ,但其祖母检测为阴性 ,提示该等位基因可能来源于其祖父。RHD基因杂合型鉴定显示叔父和父亲均有 1条正常的RHD基因、为 RHD2 70 A隐性携带者 ,其母亲为 RHD基因杂合型 ( RHD+ / RHD- ) ,该例 Rh基因型为RHD2 70 A/ RHD- ,从而形成 RHD基因阳性、D抗原阴性特性。结论 RHD2 70 A等位基因为亲代遗传基因 。

Objective: Previously the weak D and D category allele were investigated in Caucasian and Japanese families. The current study is aimed at an RHD positive, D antigen negative allele in a Chinese family. Methods: A pair of primers specific for RHD 270A allele were designed, and a sequence specific primer-PCR (SSP-PCR) method was then established to detect RHD 270A allele in 6 members of a family. Furthermore, RFLP method was used to determine the RHD zygosity in all family members. Results: The RHD 270A allele was detected in the proband, her father and uncle but not grandmother. Therefore this allele may be from grandfather and is inherited through 3 generations. The RHD zygosity test showed that the father and uncle possess one normal RHD gene as RHD 270A carriers, the mother is RHD+/RHD- heterozygote and the individual is RHD 270A/RHD-, which causes an RHD positive, D antigen negative trait. Conclusion: The RHD 270A allele is an ancestral allele, but not a spontaneous.