TABLE 1.

Previous association studies for ALS in terms of the GWAS catalog.

Year	Pop	cases/controls (discover + replication)	m	References
2007	EUR	276/271	3	Schymick et al., 2007
2007	EUR	461/450 + 876/906	1	Van Es et al., 2007
2007	EUR	221/211 + 737/721	1	Cronin et al., 2007
2008	EUR	737/721 + 1,030/1,195	3	Van Es et al., 2008
2009	EUR	958/932 + 309/404	1	Cronin et al., 2009
2009	EUR	1,821/2,258 + 538/556	14	Landers et al., 2009
2009	EUR	2,323/9,013 + 2,532/5,940	3	van Es et al., 2009
2010	EUR	405/497	4	Laaksovirta et al., 2010
2010	EUR	4,857/8,987	0	Shatunov et al., 2010
2010	EUR	639/6,257 + 183/961	2	Kwee et al., 2012
2013	EUR	4,243/5,112	19	The Alsgen Consortium, 2013
2013	EUR	6,100/7,125 + 2,074/2,556	3	Fogh et al., 2013
2014	EUR	4,377 + 435/14,431 + 4,056/3,958	10	Diekstra et al., 2014
2015	EUR	25/1,179	1	McLaughlin et al., 2015
2016	EUR	12,577/23,475 + 2,579/2,767	4	van Rheenen et al., 2016
2018	EUR	20,806/59,804 + 4,159/18,650	10	Nicolas et al., 2018
2019	EUR	4,244/3,106	1	Dekker et al., 2019
2013	CHI	506/1,859 + 706/1,777	4	Deng et al., 2013
2013	CHI	4,243 (age of ALS on-set)	15	The Alsgen Consortium, 2013
2013	CHI	250/250	174	Xie et al., 2014
2016	CHI	94/376	1	Chen C.J. et al., 2016
2017	CHI	1,234/2,850 + 576/683	7	Benyamin et al., 2017

Pop denotes which populations the GWAS was performed on, with EUR representing the European population and CHI representing the Chinese Han population; the third column is the sample size of GWAS in the discover stage and in the replication stage if conducted; m denotes the number of unique genes mapped by associated SNPs; these results are overviewed in terms of the GWAS catalog at https://www.ebi.ac.uk/gwas (until 2020-02-02). Of note, some of GWASs had only limited sample sizes, which might influence the validity of the discovered genetic variants and mapped genes in these studies. Therefore, the associations need to interpret in caution.