Clinical Heterogeneity of Atypical Pantothenate Kinase-Associated Neurodegeneration in Koreans

• Main Authors: Jae-Hyeok Lee, Jongkyu Park, Ho-Sung Ryu, Hyeyoung Park, Young Eun Kim, Jin Yong Hong, Sang Ook Nam, Young-Hee Sung, Seung-Hwan Lee, Jee-Young Lee, Myung Jun Lee, Tae-Hyoung Kim, Chul Hyoung Lyoo, Sun Ju Chung, Seong Beom Koh, Phil Hyu Lee, Jin Whan Cho, Mee Young Park, Yun Joong Kim, Young H. Sohn, Beom Seok Jeon, Myung Sik Lee
• Format: Article
• Language: English
• Published: Korean Movement Disorders Society 2016-01-01
• Series: Journal of Movement Disorders
• Subjects: Iron; Neurodegenerative diseases; Pantothenate kinase-associated neurodegeneration; Phenotype; Allele frequency
• Online Access: http://e-jmd.org/upload/jmd-15058.pdf
• ISSN: 2005-940X; 2093-4939

Objective Neurodegeneration with brain iron accumulation (NBIA) represents a group of inherited movement disorders characterized by iron accumulation in the basal ganglia. Recent advances have included the identification of new causative genes and highlighted the wide phenotypic variation between and within the specific NBIA subtypes. This study aimed to investigate the current status of NBIA in Korea. Methods We collected genetically confirmed NBIA patients from twelve nationwide referral hospitals and from a review of the literature. We conducted a study to describe the phenotypic and genotypic characteristics of Korean adults with atypical pantothenate kinase-associated neurodegeneration (PKAN). Results Four subtypes of NBIA including PKAN (n = 30), PLA2G6-related neurodegeneration (n = 2), beta-propeller protein-associated neurodegeneration (n = 1), and aceruloplasminemia (n = 1) have been identified in the Korean population. The clinical features of fifteen adults with atypical PKAN included early focal limb dystonia, parkinsonism-predominant feature, oromandibular dystonia, and isolated freezing of gait (FOG). Patients with a higher age of onset tended to present with parkinsonism and FOG. The p.R440P and p.D378G mutations are two major mutations that represent approximately 50% of the mutated alleles. Although there were no specific genotype-phenotype correlations, most patients carrying the p.D378G mutation had a late-onset, atypical form of PKAN. Conclusions We found considerable phenotypic heterogeneity in Korean adults with atypical PKAN. The age of onset may influence the presentation of extrapyramidal symptoms.