Feld R D
Department of Pathology, University of Iowa, Iowa City.
Crit Rev Clin Lab Sci. 1989;27(6):461-81. doi: 10.3109/10408368909114595.
alpha 1-Antitrypsin is a serum glycoprotein synthesized in the liver. It consists of a single polypeptide chain with a molecular weight of about 52,000. The molecule exhibits great genetic diversity with multiple codominant alleles at a single autosomal locus. The majority of the population expresses the M allele. The Z allele, which is the result of a single amino acid substitution, results in levels of alpha 1-antitrypsin that are only 10 to 15% of normal when inherited in the homozygous state. Two main pathological consequences of this state are liver and lung disease. The homozygous S phenotype has also been associated with reduced alpha 1-antitrypsin levels and pathology. The homozygous Z phenotype has an incidence of about 1 in 1700 in certain European populations. People who are heterozygous for the S or Z allele usually have alpha 1-antitrypsin levels which are about 60% of normal. The combined frequency of these alleles in the population may reach 10 to 15%. This review examines the controversy as to whether these individuals are at increased risk for pathology due to their reduced alpha 1-antitrypsin levels.
α1-抗胰蛋白酶是一种在肝脏中合成的血清糖蛋白。它由一条分子量约为52,000的单多肽链组成。该分子在单个常染色体位点具有多个共显性等位基因，表现出很大的遗传多样性。大多数人群表达M等位基因。Z等位基因是单个氨基酸取代的结果，当以纯合状态遗传时，导致α1-抗胰蛋白酶水平仅为正常水平的10%至15%。这种状态的两个主要病理后果是肝脏和肺部疾病。纯合S表型也与α1-抗胰蛋白酶水平降低和病理状况有关。在某些欧洲人群中，纯合Z表型的发病率约为1/1700。S或Z等位基因杂合的人通常α1-抗胰蛋白酶水平约为正常水平的60%。这些等位基因在人群中的合并频率可能达到10%至15%。本综述探讨了关于这些个体是否因其降低的α1-抗胰蛋白酶水平而患病理疾病风险增加的争议。
