Mohrenweiser H W, Fielek S
Pediatr Res. 1982 Nov;16(11):960-3. doi: 10.1203/00006450-198211000-00012.
Seven newborns with erythrocyte triosephosphate isomerase (TPI) activity levels consistent with the existence of a "null" allele in heterozygous form were identified among 146 Black infants studied. This allele frequency of 0.024 is ten times the frequency of 0.0024 observed in White newborns (5 heterozygotes/1048 infants). Each carrier infant has one parent with a level of TPI activity expected of a heterozygous deficient (carrier) adult, whereas the other parent has a normal level of TPI activity, as would be expected for an autosomally inherited genetic trait. All probands as well as affected parents, are asymptomatic as anticipated for heterozygotes having 50% of the expected enzymatic activity. The data are consistent with the existence of a "null" allele, designated TPI 1 degree, at the structural locus for TPI, although no immunologic or direct evidence of inactive or altered subunits was obtained. This high allele frequency implies one of every 2000 Black newborns should be homozygous deficient; this is in conflict with the low number of homozygous deficient afflicted individuals which have been actually identified to date.
在对146名黑人婴儿的研究中，发现了7名新生儿的红细胞磷酸丙糖异构酶（TPI）活性水平与杂合形式“无效”等位基因的存在相一致。该等位基因频率为0.024，是在白人新生儿（5名杂合子/1048名婴儿）中观察到的0.0024频率的10倍。每个携带该基因的婴儿有一位父母的TPI活性水平预期为杂合子缺陷（携带者）成年人的水平，而另一位父母的TPI活性水平正常，这符合常染色体遗传性状的预期。所有先证者以及受影响的父母，正如预期的具有50%预期酶活性的杂合子一样无症状。尽管没有获得无活性或改变的亚基的免疫学或直接证据，但这些数据与TPI结构位点存在一个“无效”等位基因（命名为TPI 1°）是一致的。这种高等位基因频率意味着每2000名黑人新生儿中应有一名纯合子缺陷；这与迄今为止实际确定的纯合子缺陷患者数量较少相矛盾。
