一例α1,4半乳糖基转移酶基因一碱基缺失导致p表型

目的　研究 α1,4半乳糖基转移酶基因决定 p表型的分子基础。　方法　在标准血清学鉴定红细胞表型的基础上 ,PCR扩增 p表型个体 α1,4半乳糖基转移酶基因的第 3外显子编码区序列 ,PCR产物经割胶纯化后直接进行测序分析。结果　p表型个体 α1,4半乳糖基转移酶基因第 3外显子第 30 0或30 1位核苷酸 G缺失 (TCGG→ TCG) ,导致阅读框架在第 10 1位氨基酸发生移码 ,在第 113位氨基酸处提前形成终止密码。先证者父母为杂合缺失携带者。　结论　发现了 α1,4半乳糖基转移酶基因第 3外显子第 30 0或 30 1位处 G缺失突变 ,该突变可能是 p表型的分子机理之一。

One base deletion of the α(1,4) galactosyltransferase gene responsible for p phenotype

OBJECTIVE: To study the molecular genetic basis for p phenotype. METHODS: Red blood cell phenotype of the proband was characterized by standard serological technique. Exon 3 of the alpha (1,4) galactosyltransferase gene was amplified by polymerase chain reaction from genomic DNA of the proband. The amplified PCR products were excised and purified from agarose gels and direct sequenced. RESULTS: Homozygous single nucleotide G deletion at position 300 or 301 was found in the proband, which caused a reading frame shift at codon 101,resulting in a premature stop at codon 113. Parents of the proband were heterozygous carriers. CONCLUSION: A novel single guanosine deletion at position 300 or 301 of alpha (1,4) galactosyltransferase gene was determined, which may be one facet of the molecular basis for p phenotype.