Defective ALG3 causes CDG-1d

Dol-P-Man:Man(5)GlcNAc(2)-PP-Dol alpha-1,3-mannosyltransferase (ALG3) adds the sixth mannose (although the first to be derived from dolichyl-phosphate-mannose, DOLPman) to the lipid-linked oligosaccharide (LLO) intermediate GlcNAc(2) Man(5) (PPDol)1 (Korner et al. 1999). Defects in ALG3 are associated with congenital disorder of glycosylation 1d (ALG3-CDG, CDG1d; MIM:601110), a multisystem disorder caused by a defect in glycoprotein biosynthesis and characterised by under-glycosylated serum glycoproteins. CDG type 1 diseases result in a wide variety of clinical features, such as defects in the nervous system development, psychomotor retardation, dysmorphic features, hypotonia, coagulation disorders, and immunodeficiency (Sun et al. 2005).

Dol-P-Man:Man(5)GlcNAc(2)-PP-Dol α-1,3-甘露糖基转移酶（ALG3）将第六个甘露糖（尽管是第一个由多聚磷酸酰基甘露糖（DOLPman）衍生而来）添加至脂联寡糖（LLO）中间体GlcNAc(2)Man(5)（PPDol）1（Korner等人，1999年）。ALG3基因的缺陷与先天性糖基化障碍1d型（ALG3-CDG，CDG1d；MIM:601110）相关联，这是一种由糖蛋白生物合成缺陷引起的多系统性疾病，其特征为血清糖蛋白低糖基化。CDG 1型疾病导致广泛的临床特征，包括神经系统发育缺陷、精神运动迟缓、外观异常、肌张力低下、凝血障碍和免疫缺陷（Sun等人，2005年）。