1. Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea
2. Department of Rehabilitation Medicine, The Catholic University of Korea, Street Vincent’s Hospital, 93-6 Ji-dong, Paldal-gu, Suwon, Gyeonggi-do 442-723, Republic of Korea
3. Samkwang Medical Laboratories, 9-60 Yangjae-dong, Seocho-gu, Seoul 137-887, Republic of Korea
4. Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, 62 Yeouido-dong, Yeongdeungpo-gu, Seoul 150-713, Republic of Korea
5. Department of Laboratory Medicine, Yonsei University Wonju College of Medicine, 20 Ilsan-ro, Ilsandong, Wonju, Gangwon-do 220-701, Republic of Korea
6. Department of Laboratory Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, 712 Eonjuro, Gangnam-gu, Seoul 135-720, Republic of Korea
7. Department of Rehabilitation, Institute of Neuromuscular Disease, Gangnam Severance Hospital, Yonsei University College of Medicine, 712 Eonjuro, Gangnam-gu, Seoul 135-720, Republic of Korea