综述与专论: 异染性脑白质营养不良的研究进展

异染性脑白质营养不良（metachromatic leukodystrophy，MLD）是一种由芳基硫酸酯酶A（arylsulfatase A，ARSA）基因突变导致的罕见遗传性白质脑病。MLD的临床表现及疾病进展速度存在个体差异，但几乎所有的患者最终均会出现运动及认知功能完全丧失。临床上根据患者的发病年龄及病情严重程度分为晚婴型、青少年型及成人型。MLD的临床诊断包括进行性神经系统倒退及典型的头颅核磁共振成像（magnetic resonance imaging，MRI）表现。其临床表现与多种疾病类似，需与其他白质脑病和溶酶体贮积病进行鉴别。MLD暂无有效治疗方法，目前仅能对患者进行对症支持治疗。造血干细胞移植或骨髓移植、酶替代治疗和基因治疗是关于MLD治疗的研究热点。最近研究发现，鞘内注射重组人芳基硫酸酯酶A（rhASA）可延缓疾病的进展。针对MLD家系进行有效的产前分子诊断是预防MLD发生的主要方法。

Reviews and Monographs: Research Progress of Metachromatic Leukodystrophy

Metachromatic leukodystrophy (MLD) is a rare hereditary leukoencephalopathy caused by arylsulfatase A (ARSA) gene mutation. There are individual differences in the clinical manifestations and disease progression speed of MLD, but almost all patients will eventually have complete loss of motor and cognitive functions. Clinically, patients are divided into late infantile onset, juvenile onset and adult onset according to their age of onset and severity of illness. The clinical diagnosis of MLD includes progressive neurological regression and typical magnetic resonance imaging (MRI) findings. Its clinical manifestations are similar to many diseases, and it needs to be differentiated from other leukoencephalopathies and lysosomal storage diseases. There is no effective treatment for MLD. Hematopoietic stem cell transplantation or bone marrow transplantation, enzyme replacement therapy and gene therapy are the research hotspots of MLD treatment. At present, only symptomatic support treatment can be carried out for patients. Recent studies have found that intrathecal injection of recombinant human arylsulfatase A (rhASA) could delay the progress of the disease. Effective prenatal molecular diagnosis for MLD families is the main method to prevent the occurrence of MLD.