Brief Communication

Ann Lab Med 2020; 40(4): 326-330

Published online July 1, 2020

Copyright © Korean Society for Laboratory Medicine.

Carrier Frequency of Spinal Muscular Atrophy in a Large-scale Korean Population

Jong Eun Park, M.D.1 , Sun Ae Yun, M.T.2 , Eun Youn Roh, M.D.3 , Jong Hyun Yoon, M.D.3 , Sue Shin, M.D.3 , and Chang-Seok Ki, M.D.4

1Department of Laboratory Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea; 2Center for Clinical Medicine, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Korea; 3Department of Laboratory Medicine, Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea; 4GC Genome, Yongin, Korea

Correspondence to: Sue Shin, M.D.
Department of Laboratory Medicine, Boramae Hospital, Seoul National University College of Medicine, 20 Boramae-ro 5-gil, Dongjak-gu, Seoul 07061, Korea
Tel: +82 2-870-2602 Fax: +82 2-870-2620. E-mail:

Chang-Seok Ki, M.D.
GC Genome, 107 Ihyeon-ro 30beon-gil, Giheung-gu, Yongin 16924, Korea
Tel: +82-31-260-0601 Fax: +82-31-260-9087. E-mail:

Received: August 16, 2019; Revised: September 29, 2019; Accepted: January 16, 2020

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by progressive proximal muscle weakness and atrophy. Given the recent introduction of gene therapies, knowledge of the SMA carrier frequency in various populations has become important for developing screening programs for this disease. In total, 1,581 anonymous DNA samples from an umbilical cord blood bank were tested for SMN1 and SMN2 gene copies using a multiplex ligation-dependent probe amplification assay. Twenty-nine of the 1,581 newborns [1.83%; 95% confidence interval (CI), 1.25–2.66%] were SMA carriers with one copy of SMN1, and no homozygous SMN1 deletion was detected. The carrier frequency in this population was estimated to be 1,834 per 100,000 (95% CI, 1,254–2,659) or 1 in 55 (95% CI, 1/79–1/38). Our data indicate that SMA carriers are not uncommon in the Korean population and may serve as a reference for designing a population screening program in Korea.

Keywords: Korea, Spinal muscular atrophy, Carrier frequency, multiplex ligation-dependent probe amplification

Fig. 1.

Distribution of SMN1 and SMN2 copy numbers. Each bar represents the percentage of SMN1 and SMN2 copy numbers in the 1,581 umbilical cord blood samples of newborns included in this study. *One newborn was suspected as a SMN1 silent (2+0) carrier.

Carrier frequency of spinal muscular atrophy in East Asian populations

EthnicityTotal samples (N)Carrier frequency % (95% CI)MethodReference
China5691.58 (0.77–3.09)Real-time PCRChan, et al. 2004 [10]
China1,7122.39 (1.75–3.27)DHPLCSheng-Yuan, et al. 2010 [11]
China1,7412.58 (1.91–3.47)Real-time PCRQu, et al. 2013 [12]
China4,7191.90 (1.54–2.35)DHPLCGong, et al. 2013 [13]
China4,9311.24 (0.96–1.60)DHPLC and multiplex PCRTan, et al. 2018 [14]
Taiwan3101.94 (0.79–4.37)MLPAHuang, et al. 2007 [15]
Taiwan1632.50 (0.79–6.56)Multiplex PCR and CEChen, et al. 2011 [16]
Taiwan107,6112.10 (2.03–2.20)DHPLC and multiplex PCRSu, et al. 2011 [17]
Taiwan4533.97 (2.44–6.33)HRMA, DHPLC, and MLPAWang, et al. 2015 [18]
Korea3262.15 (0.94–4.57)Real-time PCRLee, et al. 2004 [7]
Korea1002.00 (0.35–7.74)MLPAYoon, et al. 2010 [6]
Korea1,5811.83 (1.25–2.66)MLPAThis study

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