Zittoun J, Fischer A, Marquet J, Pérignon J L, Lagrue A, Griscelli C
Laboratoire Central d'Hématologie-Immunologie, Hôpital Henri Mondor, Creteil.
Acta Paediatr Scand. 1987 Nov;76(6):991-8. doi: 10.1111/j.1651-2227.1987.tb17284.x.
We report a case of methionine synthase deficiency associated with cellular immune deficiency discovered in a 14-year-old boy. Principal findings were: developmental delay, recurrent upper and lower respiratory tract infections, megaloblastic anemia, discovered at 3 months of age, unresponsive to cyanocobalamin and poorly responsive to folinic acid. Biochemical studies showed: an abnormal deoxyuridine suppression test despite normal serum folate, cobalamin and transcobalamin levels; a normal intracellular uptake of these two coenzymes; and an absolute requirement of methionine for fibroblast growth, suggestive of defective methionine synthesis. An absence of methionine synthase activity in the patient's bone marrow and a profound depression of this activity in lymphocytes and liver were found. Hypergammaglobulinemia with variable lymphopenia, depressed lymphocyte transformation after lectin or recall-antigen stimulation, defective delayed-type hypersensitivity and decreased natural killer activity were noted as well. The patient died at the age of 14.
我们报告了一例在一名14岁男孩中发现的与细胞免疫缺陷相关的甲硫氨酸合成酶缺乏症病例。主要发现如下：发育迟缓、反复的上呼吸道和下呼吸道感染、巨幼细胞贫血，于3个月大时发现，对氰钴胺无反应，对亚叶酸反应不佳。生化研究显示：尽管血清叶酸、钴胺素和转钴胺素水平正常，但脱氧尿苷抑制试验异常；这两种辅酶的细胞内摄取正常；成纤维细胞生长绝对需要甲硫氨酸，提示甲硫氨酸合成存在缺陷。在患者的骨髓中未检测到甲硫氨酸合成酶活性，在淋巴细胞和肝脏中该活性严重降低。还注意到有高球蛋白血症伴不同程度的淋巴细胞减少、凝集素或回忆抗原刺激后淋巴细胞转化受抑制、迟发型超敏反应缺陷以及自然杀伤活性降低。该患者于14岁时死亡。
