A similar, less severe, metabolic disorder is congenital lactase deficiency.类似的，病症略轻为一点的代谢紊乱疾病是乳糖分解酶素缺乏症。
Congenital lactose intolerance is very rare and is an inherited metabolic disorder rather than an allergy.先天性的乳糖不耐受是非常罕见的遗传性的代谢紊乱，而并非过敏。