Al Balwi Mohammed, Al Ajaji Sulaiman, Al Abdulkareem Ibrahim, Hajeer Ali
King Saud bin Abdulaziz University for Health Sciences, College of Medicine, Riyadh, 11426, Saudi Arabia.
Cases J. 2009 Jul 30;2:8391. doi: 10.4076/1757-1626-2-8391.
The V(D)J rearrangement of B and T cell lymphocytes during the recombination process, which is essential for the development of normal immune system function, depends critically on the presence of the recombination activating enzymes, RAG1 and RAG2. Mutations in RAG1 or RAG2 can lead to a spectrum of disorders, ranging from typical B-T-severe combined immunodeficiency to Omenn's syndrome.
A two-month-old Saudi baby girl presented with fever, respiratory distress due to bronchiolitis, exfoliative erythroderma and a family history of childhood death within the first few months of life in two of her sisters who had had a similar clinical presentation to her own. Immunological work-up revealed an absence of circulating B lymphocytes, whereas various numbers of activated T lymphocytes were present in the peripheral blood and in the skin.
In this case, mutation analysis of the recombination activating genes RAG1 or RAG2 revealed a homozygous missense (c.1299G>A) mutation in the RAG1 gene. This is the first report in the literature linking a homozygous R396H mutation in the RAG1 gene with presentation of Omenn's syndrome.
在重组过程中，B和T淋巴细胞的V(D)J重排对于正常免疫系统功能的发育至关重要，这一过程严重依赖重组激活酶RAG1和RAG2的存在。RAG1或RAG2的突变可导致一系列疾病，从典型的B-T重症联合免疫缺陷到奥门氏综合征。
一名两个月大的沙特女婴出现发热、因细支气管炎导致的呼吸窘迫、剥脱性红皮病，且她的两个姐姐在生命的头几个月内有类似临床表现并在儿童期死亡，存在家族病史。免疫检查发现循环B淋巴细胞缺失，而外周血和皮肤中存在不同数量的活化T淋巴细胞。
在该病例中，对重组激活基因RAG1或RAG2的突变分析显示RAG1基因存在纯合错义（c.1299G>A）突变。这是文献中首次报道将RAG1基因的纯合R396H突变与奥门氏综合征的表现联系起来。
