Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland.
Ann Med. 2009;41(8):568-75. doi: 10.1080/07853890903121033.
Lactase non-persistence (adult-type hypolactasia) is present in more than half of the human population and is caused by the down-regulation of lactase enzyme activity during childhood. Congenital lactase deficiency (CLD) is a rare severe gastrointestinal disorder of new-borns enriched in the Finnish population. Both lactase deficiencies are autosomal recessive traits and characterized by diminished expression of lactase activity in the intestine. Genetic variants underlying both forms have been identified. Here we review the current understanding of the molecular defects of human lactase deficiencies and their phenotype-genotype correlation, the implications on clinical practice, and the understanding of their function and role in human evolution.
乳糖酶持续性缺乏（成人型低乳糖酶血症）存在于超过半数的人群中，是由于儿童期乳糖酶活性下调引起的。先天性乳糖酶缺乏症（CLD）是芬兰人群中一种罕见的新生儿严重胃肠道疾病。这两种乳糖酶缺乏症均为常染色体隐性遗传特征，表现为肠道乳糖酶活性降低。两种形式的乳糖酶缺乏症的遗传变异已被确定。本文综述了人类乳糖酶缺乏症的分子缺陷及其表型-基因型相关性、对临床实践的影响，以及对其功能和在人类进化中的作用的理解。
