Navon R, Sandbank U, Frisch A, Baram D, Adam A
Prenat Diagn. 1986 May-Jun;6(3):169-76. doi: 10.1002/pd.1970060303.
Amniocentesis and subsequent tests are reported on a fetus conceived of a rare mating type: its mother has an intermediate level of beta hexosaminidase A (HEX A), characteristic of carriers of Tay-Sachs disease (TSD), while the father suffers from an adult-onset GM2 gangliosidosis (AOG) with severe HEX A deficiency. Activity of HEX A in the cultured fetal cells was very low when measured by the heat-inactivation method, thus showing the typical biochemical phenotype of TSD fetuses. However, upon separation of HEX isozymes by ion exchange chromatography, residual HEX A (17 per cent of total HEX) was demonstrated. Also in contrast to TSD fetuses, this fetus' fibroblasts were able to synthesize the precursor of alpha chains of HEX, and ultrastructural examination of its brain revealed few atypical lamellar bodies, unlike those found in TSD fetuses of the same gestational age. It is therefore concluded that the fetus was not affected with TSD, but rather with AOG.
其母亲的β-己糖胺酶A（HEX A）水平处于中等，这是泰-萨克斯病（TSD）携带者的特征，而父亲患有成年型GM2神经节苷脂沉积症（AOG），伴有严重的HEX A缺乏。通过热灭活法检测，培养的胎儿细胞中HEX A的活性非常低，从而显示出TSD胎儿典型的生化表型。然而，通过离子交换色谱法分离HEX同工酶后，发现了残留的HEX A（占总HEX的17%）。同样与TSD胎儿不同的是，该胎儿的成纤维细胞能够合成HEXα链的前体，并且对其大脑进行的超微结构检查显示，与相同孕周的TSD胎儿相比，非典型板层小体较少。因此得出结论，该胎儿未患TSD，而是患有AOG。
