摘要
目的 研究 46,XY女性性反转患者发病的分子机理。方法 应用聚合酶链反应 (polymerasechain reaction,PCR)扩增 1例性反转患者和其父亲的 SRY基因片段 ;PCR产物连接到 p UCm-T载体上 ,在 ABI 3 77-3自动测序仪上完成测序以查明突变 ;应用 PCR-限制性酶切对 DNA测序的结果进行检测。结果 发现该患者的 SRY基因存在点突变 (T3 87A) ,导致 SRY蛋白发生氨基酸翻译终止 (酪氨酸 12 9终止密码 ) ,患者父亲的序列正常。由于患者 SRY序列中增加一个 Mae 酶切位点 ,PCR-限制性内切酶酶切电泳检测 ,结果显示患者出现 3条带 (13 1bp、2 3 1bp和 2 47bp) ,而正常人出现 2条带 (13 1bp和 478bp) ,进一步验证了序列分析的结果。经查证数据库 ,该突变是一个未见报道的新型 SRY基因突变。结论 这一新型突变的发现 ,有助于进一步阐明 46。
Objective: To investigate the molecular mechanism of a Chinese patient with 46, XY sex reversal. Methods: DNA fragments of the SRY gene from the typical XY female sex reversal patient and her father were amplified by polymerase-chain reaction (PCR). The amplified PCR fragments were cloned into the pUCm-T vector, and direct sequencing was carried out on an ABI 377-3 automated DNA sequencer to detect the mutation. PCR-restriction enzyme digestion was applied to detect the results of DNA sequencing. Results: A novel mutation of the SRY gene was identified in the XY sex reversal patient of this study. A T is replaced by an A in codon 129 at position +387, resulting in the replacement of the polar amino acid tyrosine (TAT) by the stop code (TAA) in the HMG-box, whereas her father was proved to have the wild-type sequence. Because the mutation introduced an enzyme site of Mae III, the PCR-restrict enzyme digestion showed that there were three bands (131 bp, 231 bp and 247 bp) in the patient, whereas two bands (131 bp and 478 bp) in normal man. It verified the results of sequencing analysis. The results after searching The Human Gene Mutation Database showed that this mutation was not described before and should be a new mutation. Conclusion: The novel mutation in SRY gene has provided valuable information for the understanding of molecular mechanism of the patient with 46,XY female sex reversal.
出处
《中华医学遗传学杂志》
EI
CAS
CSCD
2003年第5期369-372,共4页
Chinese Journal of Medical Genetics
基金
973项目( GI9990 5590 1 )
