Browett P J, Hoffbrand A V, Norton J D
Department of Haematology, Royal Free Hospital School of Medicine, Hampstead, London, U.K.
Leuk Res. 1988;12(4):321-6. doi: 10.1016/0145-2126(88)90047-1.
The X-chromosome linked gene encoding hypoxanthine phosphoribosyl transferase (HPRT) has been reported to provide a novel approach to the investigation of cell monoclonality in females based on non-random methylation-sensitive restriction enzyme cleavage of the active vs inactive HPRT alleles and a polymorphic Bam HI restriction site to distinguish the maternal and paternal gene copies. In a survey of 80 females, which included 65 cases of hemopoietic malignancy and 15 normal individuals, we found only nine (11.3%) to be heterozygous (informative) for the Bam HI polymorphism. Monoclonality was demonstrable by HPRT gene analysis in five of six informative cases of leukemia, the exception being a case of acute myeloid leukemia which displayed anomalous methylation of the HPRT gene. Our studies suggest that the applicability of the HPRT gene probe strategy may be limited by (1) the low frequency of informative cases and (2) potential inappropriate methylation of the HPRT gene in a proportion of cases.
据报道，编码次黄嘌呤磷酸核糖基转移酶（HPRT）的X染色体连锁基因，基于活性与非活性HPRT等位基因的非随机甲基化敏感限制性酶切以及一个多态性Bam HI限制性位点来区分母本和父本基因拷贝，为研究女性细胞单克隆性提供了一种新方法。在一项对80名女性的调查中，包括65例造血系统恶性肿瘤患者和15名正常个体，我们发现只有9名（11.3%）对于Bam HI多态性是杂合的（信息丰富的）。在6例信息丰富的白血病病例中，通过HPRT基因分析证实有5例存在单克隆性，例外的是1例急性髓细胞白血病病例，其HPRT基因显示出异常甲基化。我们的研究表明，HPRT基因探针策略的适用性可能受到以下限制：（1）信息丰富病例的频率较低；（2）一部分病例中HPRT基因可能存在不适当的甲基化。
