Barshop B A, Wolff J, Nyhan W L, Yu A, Prodanos C, Jones G, Sweetman L, Leslie J, Holm J, Green R
Department of Pediatrics, University of California San Diego, La Jolla 92093.
Am J Med Genet. 1990 Feb;35(2):222-8. doi: 10.1002/ajmg.1320350216.
An infant with deficiency of transcobalamin II (TCII) presented with virtually complete failure to thrive and life-threatening pancytopenia. Methylmalonic acid and homocystine were found in the urine. The concentration of B12 in the serum was 26 pg/ml. Fibroblasts derived from the patient failed to take up labeled cobalamin in the absence of a source of TCII. Uptake was normal in the presence of TCII. Treatment with parenteral cobalamin reversed the clinical and hematological manifestations of the disease but she developed glossitis when the interval between injections was lengthened. Intestinal absorption of 57Co-cobalamin was less than 1% and remained abnormal when highly purified human intrinsic factor was given along with the labeled B12. Absorption improved when the labeled B12 was given together with rabbit TCII. The data suggest that TCII as well as intrinsic factor is required for transport of cobalamin from the intestine to the blood.
一名患有转钴胺素II（TCII）缺乏症的婴儿出现了几乎完全无法茁壮成长以及危及生命的全血细胞减少症。尿液中发现了甲基丙二酸和高胱氨酸。血清中维生素B12的浓度为26 pg/ml。在没有TCII来源的情况下，来自该患者的成纤维细胞无法摄取标记的钴胺素。在有TCII存在时摄取正常。胃肠外给予钴胺素治疗可逆转该疾病的临床和血液学表现，但当注射间隔延长时，她出现了舌炎。57Co-钴胺素的肠道吸收小于1%，并且当与标记的维生素B12一起给予高度纯化的人内因子时，吸收仍异常。当标记的维生素B12与兔TCII一起给予时，吸收得到改善。数据表明，钴胺素从肠道转运到血液中既需要TCII也需要内因子。
