Bose Rahul, Nandagopal Krishnadas
Indian J Biochem Biophys. 2013 Oct;50(5):345-56.
Adenosine deaminase deficiency accounts for approximately 15-20% of severe combined immunodeficiency in humans. The gene for adenosine deaminase is located on chromosome 20q12-q13.11 and codes for an aminohydrolase that catalyzes the deamination of adenosine and deoxyadenosine to inosine and deoxyinosine, respectively. Absence of the enzyme causes a build-up of the substrates in addition to excess deoxyadenosine triphosphate, thereby compromising the regenerative capacity of the immune system. Due to underlying allelic heterogeneity, the disorder manifests as a spectrum, ranging from neonatal onset severe combined immunodeficiency to apparently normal partial adenosine deaminase deficiency. Tandem mass spectrometry coupled with high efficiency separation systems enables postnatal diagnosis of the disorder, while prenatal diagnosis relies on assaying enzyme activity in cultured amniotic fibroblasts or chorionic villi sampling. Screening of adenosine deaminase deficiency for relatives-at-risk may reduce costs of treatment and ensure timely medical intervention as applicable. This article reviews the genetic, biochemical and clinical aspects of adenosine deaminase deficiency.
腺苷脱氨酶缺乏症约占人类严重联合免疫缺陷病例的15%-20%。腺苷脱氨酶基因位于20号染色体q12-q13.11区域，编码一种氨基水解酶，该酶分别催化腺苷和脱氧腺苷脱氨生成肌苷和脱氧肌苷。该酶的缺失除了导致三磷酸脱氧腺苷过量外，还会使底物蓄积，从而损害免疫系统的再生能力。由于潜在的等位基因异质性，该疾病表现为一个谱系，范围从新生儿期发病的严重联合免疫缺陷到明显正常的部分腺苷脱氨酶缺乏。串联质谱联用高效分离系统可实现该疾病的产后诊断，而产前诊断则依赖于检测培养的羊膜成纤维细胞或绒毛取样中的酶活性。对有风险的亲属进行腺苷脱氨酶缺乏症筛查可降低治疗成本，并确保在适用时及时进行医学干预。本文综述了腺苷脱氨酶缺乏症的遗传、生化和临床方面。
