Tedesco T A, Miller K L, Rawnsley B E, Adams M C, Markus H B, Orkwiszewski K G, Mellman W J
Am J Hum Genet. 1977 May;29(3):240-7.
We have previously reported the existence of a polymorphism that causes black populations to have lower mean RBC galactokinase activity than comparable white populations. We have designated this allele the Philadelphia variant, GALKP, and have suggested that it is common in blacks and rare in whites. GALKP individuals have normal WBC GALK activity, in contrast to the half normal WBC GALK activities of heterozygotes for the allele (GALKG) that causes the galactokinase-deficient form of galactosemia. In one family, we have presented evidence for the existence of two sisters heterozygous for both GALKG and GALKP alleles. These individuals have 50% normal WBC GALK activity and less than 50% normal red cell activity. The latter finding indicates that the two variant GALK alleles additively affect RBC activity. The WBC results suggest that the low activity of GALK in RBC of individuals with the GALKP allele is due to its relative instability. We could obtain no evidence for such instability from studies of high reticulocyte bloods or RBC fractionation. Furthermore, we could not demonstrate that the GALK in WBC from GALKP individuals has altered electrophoretic migration.
我们之前报道过一种多态性的存在，该多态性导致黑人人群的平均红细胞半乳糖激酶活性低于与之可比的白人人群。我们将这个等位基因命名为费城变体，即GALKP，并认为它在黑人中常见，在白人中罕见。与导致半乳糖血症的半乳糖激酶缺陷型等位基因（GALKG）的杂合子白细胞半乳糖激酶活性只有正常水平一半相比，GALKP个体的白细胞半乳糖激酶活性正常。在一个家族中，我们提供了证据，证明存在两名同时杂合GALKG和GALKP等位基因的姐妹。这些个体的白细胞半乳糖激酶活性为正常水平的50%，红细胞活性不到正常水平的50%。后一个发现表明，这两个变异的半乳糖激酶等位基因对红细胞活性有累加影响。白细胞的结果表明，具有GALKP等位基因的个体红细胞中半乳糖激酶活性较低是由于其相对不稳定性。从高网织红细胞血液或红细胞分级分离研究中，我们没有获得这种不稳定性的证据。此外，我们无法证明来自GALKP个体的白细胞中的半乳糖激酶有改变的电泳迁移率。
