[Phenotypic and genotypic features of twenty children with classic pantothenate kinase-associated neurodegeneration].

Objective: To explore the phenotypic and genotypic characteristics in Chinese children with classic pantothenate kinase-associated neurodegeneration (PKAN). Method: The clinical, radiographic and genetic data of all PKAN patients diagnosed at pediatric department of Peking University First Hospital from November 2006 to December 2016 were retrospectively collected and analyzed. Result: Twenty patients with classic PKAN were included in the study. The median age at onset was 3.5 years (ranging from 1.0 to 10.0 years), and the most common initial symptom was gait disturbance (16 cases). At the last evaluation, the clinical features were limbs dystonia (20 cases), dysarthria (16 cases), dysphagia (11 cases), pyramidal sign (7 cases), mental regression (3 cases) and pigmentary retinopathy (5 cases). For those classic PKAN patients, the median time from onset of disease to loss of independent ambulation was 6.9 years (ranging from 2.0 to 12.0 years). Imaging data showed, except "eye of tiger" in MRI (19 cases), globus pallidus calcification in CT was also found in four patients. In gene testing, 26 different mutations in PANK2 gene were identified, and 16 of 26 were novel mutations. Moreover, c. 1502T>C (p.Ile501Asn) was the most common mutation (4 cases). Conclusion: Dystonia is the major neurologic feature of classic PKAN. Disease progression is rapid, with loss of independent ambulation within 10 years after onset. Except "eye of tiger" in MRI, globus pallidus calcification in CT may be another imaging feature of PKAN.Sixteen novel mutations of PANK2 gene were identified in the study.目的： 分析经典型泛酸激酶相关神经变性患儿的临床和基因特点。 方法： 回顾性总结北京大学第一医院2006年11月至2016年12月确诊为泛酸激酶相关神经变性的患儿资料，分析其临床表现、影像学特点和基因检查结果。 结果： 共20例确诊为泛酸激酶相关神经变性的患儿纳入研究，均为经典型，起病年龄的中位数为3.5(1.0～10.0)岁，首发症状主要为下肢肌张力不全(16例)，末次随访所有患儿均出现肢体肌张力不全，部分逐渐出现吞咽障碍(11例)、言语障碍(16例)、锥体束受累(7例)、智力倒退(3例)、视网膜色素变性(5例)，起病至失去行走能力的中位数年龄为6.9(2.0～12.0)年。19例患儿头颅磁共振成像(MRI)存在"虎眼征"，4例患儿CT发现苍白球区钙化。共发现26种基因突变，其中16种为新发突变。c.1502T>C (p.Ile501Asn)突变最多见(4例)。 结论： 经典型泛酸激酶相关神经变性患儿以肌张力不全为主要临床表现，进展至失去行走能力时间短。除头颅MRI有"虎眼征"表现外，头颅CT苍白球区钙化可能为泛酸激酶相关神经变性的另一影像学特征。本组发现16种PANK2基因新突变。.