Centro de Investigaciones Endocrinológicas, División de Endocrinología, Hospital de Niños R Gutiérrez, Gallo 1330, Buenos Aires, Argentina.
Best Pract Res Clin Endocrinol Metab. 2011 Feb;25(1):101-13. doi: 10.1016/j.beem.2010.08.010.
The acid-labile subunit (ALS) protein is crucial for maintaining the integrity of the circulating IGF/IGFBP system. In humans, complete ALS deficiency is characterized by severely reduced serum IGF-I and IGFBP-3 concentrations that is incongruent with the associated mild growth retardation (height SDS -2 to -3 SDS before and during puberty). Twenty-one patients have been described with ALS deficiency, representing 16 unique homozygous or compound heterozygous inactivating mutations of the IGFALS gene. Pubertal delay in boys and insulin insensitivity are common findings. In the assessment of a child with short stature ALS deficiency should be consider in those patients presenting: 1) a normal response to GH stimulation test, 2) low IGF-I levels associated with more profoundly reduced IGFBP-3 levels, 3) a mild growth retardation, apparently out of proportion to the degree of IGF-I and IGFBP-3 deficits, 4) lack of response to an IGF generation test and 5) insulin insensitivity.
酸不稳定亚基 (ALS) 蛋白对于维持循环 IGF/IGFBP 系统的完整性至关重要。在人类中，完全的 ALS 缺乏症的特征是血清 IGF-I 和 IGFBP-3 浓度严重降低，这与相关的轻度生长迟缓（青春期前和青春期身高 SDS-2 至 -3 SDS）不一致。已经描述了 21 例 ALS 缺乏症患者，代表 IGFALS 基因的 16 个独特的纯合子或复合杂合子失活突变。男孩的青春期延迟和胰岛素不敏感是常见的发现。在评估身材矮小的儿童时，如果患者存在以下情况，应考虑 ALS 缺乏症：1）生长激素刺激试验正常反应，2）IGF-I 水平低，同时 IGFBP-3 水平显著降低，3）生长迟缓程度较轻，明显与 IGF-I 和 IGFBP-3 缺乏程度不成比例，4）对 IGF 生成试验无反应，5）胰岛素不敏感。
