35例黏多糖贮积症Ⅳ型患儿临床特点及酶学诊断

Clinical characteristics and enzyme assays of 35 cases with mucopolysaccharidosis type Ⅳ

目的总结中国人黏多糖贮积症(MPS)Ⅳ型的临床特点及酶学诊断,提供MPS鉴别诊断要点。方法对2006年6月至2011年11月因矮小伴有多发骨骼畸形就诊并诊断为MPSⅣ型患儿的临床特点、骨骼影像学、尿黏多糖定性电泳及酶活性检测结果进行回顾分析。结果 35例患儿诊断为MPSⅣ型(ⅣA型34例,ⅣB型1例),所有患儿具有不同程度的MPSⅣ型临床特点,包括矮小、脊柱发育不良、关节畸形,但智能发育正常;脊柱X线显示,胸腰椎椎体前缘鸟嘴样改变及肋骨飘带状等;80%患儿的尿液黏多糖定性阳性,尿液黏多糖电泳显示CS区带;34例MPSⅣA型患儿白细胞半乳糖胺-6-硫酸盐硫酸酯酶(GALNS)活性极低[(0.85±1.33)nmol/(17 h.mg)],1例MPSⅣB型患儿β-半乳糖苷酶(GLB1)酶活性极低[5.03 nmol/(mg.h)]。结论对临床高度怀疑MPS的患儿,可检测尿液黏多糖进行初步筛查,再以酶活性分析来确诊。

Objective This paper focused on the summary of clinical manifestations and enzyme activity determination in Chinese patients with mucopolysaccharidosis type Ⅳ（MPS Ⅳ） to provide key points of differential diagnosis for MPS.Methods During Jun.2006-Nov.2011,the patients with short stature and multiple skeletal dysplasia diagnosed as MPS Ⅳ were enrolled to this study.The clinical characteristics,skeletal X-ray features,urinary glycosaminoglycans（GAGs） and related enzyme activity were analyzed retrospectively.Results Thirty-five patients were diagnosed as MPS Ⅳ（34 patients as type ⅣA,1 patient as type ⅣB）.All of the 35 patients had different degrees of clinical characteristics of MPS Ⅳ that include short stature,spine and joint deformity,but with normal intelligence.The skeletal X-ray examination showed bullet-like changes in anterior end-plate of the thoracolumbar vertebral bodies and ribbon-like ribs.Urine GAGs qualitative test showed positive in 80% patients,and the urine GAGs electrophoresis test showed the chondroitin sulfate zone in all patients.The white blood cell galactosamine-6-sulfate sulfatase enzyme activity were very low（0.85 ± 1.33 nmol /（17 h·mg）） in 34 patients with MPS ⅣA,and the β-galactosidase enzyme activity was very low（5.03 nmol /（mg·h）） in one patient with MPS ⅣB.Conclusions MPS Ⅳ can be initially screened by urine GAGs analysis,and be diagnosed definitely by enzyme activity determination.