Gazi University Hospital, Pediatric Metabolic Unit, Ankara, Turkey.
Eur J Paediatr Neurol. 2012 Sep;16(5):554-6. doi: 10.1016/j.ejpn.2011.12.011. Epub 2012 Jan 10.
Congenital disorders of glycosylation (CDG) are genetic diseases with an extremely broad spectrum of clinical presentations due to defective glycosylation of glycoproteins and glycolipids. Some 45 CDG types have been reported since the first clinical description in 1980. Protein glycosylation disorders are defects in protein N- and/or O-glycosylation. Dolichol phosphate is the carrier of the N-glycan during their assembly first at the outside and subsequently at the inside of the endoplasmic reticulum (ER) membrane, and hence is a key molecule in protein glycosylation. Recently, defects have been identified in the last three steps of the dolichol phosphate biosynthesis: dolicholkinase deficiency (DK1-CDG), steroid 5alpha-reductase type 3 deficiency (SRD5A3-CDG), and dehydrodolichyl diphosphate synthase deficiency (DHDDS-CDG). We report on a patient with SRD5A3-CDG carrying a novel (homozygous) mutation. The diagnostic features of this novel inborn error of glycosylation are psychomotor retardation, nystagmus, visual impairment due to variable eye malformations, cerebellar abnormalities/ataxia, and often ichthyosiform skin lesions.
先天性糖基化障碍（CDG）是一种由于糖蛋白和糖脂糖基化缺陷导致的具有广泛临床表现的遗传性疾病。自 1980 年首次临床描述以来，已经报道了约 45 种 CDG 类型。蛋白糖基化障碍是蛋白 N-和/或 O-糖基化的缺陷。多萜醇磷酸是糖蛋白装配过程中 N-聚糖的载体，首先在外质网（ER）膜的外部，然后在内部进行，因此是蛋白糖基化的关键分子。最近，已经鉴定出多萜醇磷酸生物合成的最后三个步骤中的缺陷：多萜醇激酶缺乏症（DK1-CDG）、类固醇 5α-还原酶 3 缺乏症（SRD5A3-CDG）和脱氢多萜醇二磷酸合酶缺乏症（DHDDS-CDG）。我们报告了一例 SRD5A3-CDG 患者，携带一种新的（纯合）突变。这种新的先天性糖基化错误的诊断特征是精神运动发育迟缓、眼球震颤、由于各种眼部畸形导致的视力损害、小脑异常/共济失调，以及常伴有鱼鳞样皮肤损伤。
