Human acid-labile subunit deficiency: clinical, endocrine and metabolic consequences.

摘要: The majority of insulin-like growth factor (IGF)-I and IGF-II circulate in the serum as a complex with binding protein (IGFBP)-3 or IGFBP-5, an acid-labile subunit (ALS). function ALS is to prolong half-life IGF-I-IGFBP-3/IGFBP-5 binary complexes. Fourteen different mutations human IGFALS gene have been identified 17 patients, suggesting that deficiency may be prevalent subset patients extraordinarily low levels IGF-I IGFBP-3 remain abnormally upon hormone stimulation. Postnatal was clearly affected. Commonly, height standard deviation score before puberty between -2 -3, approximately 1.4 SD shorter than midparental SDS. Pubertal delay found 50% patients. Circulating IGF-II, IGFBP-1, -3 were reduced, greatest reduction observed for IGFBP-3. Insulin insensitivity common finding, some presented bone mineral density. Human represents unique condition which lack proteins results disruption entire IGF circulating system. Despite profound deficiency, there only mild impact on postnatal growth. preserved expression locally produced might responsible preservation linear near normal limits.