“…In previous studies, the incidents of STGD-associated variants in ABCA4 were 70.5% in the Russian Federation, 70.8% in Korea, 67% in Portugal, and 60.5% in Spain (Fumagalli et al, 2001;Maia-Lopes et al, 2009;Riveiro-Alvarez et al, 2009;Sung, Choi, Shim, & Song, 2019;Zolnikova et al, 2017). In previous studies, the incidents of STGD-associated variants in ABCA4 were 70.5% in the Russian Federation, 70.8% in Korea, 67% in Portugal, and 60.5% in Spain (Fumagalli et al, 2001;Maia-Lopes et al, 2009;Riveiro-Alvarez et al, 2009;Sung, Choi, Shim, & Song, 2019;Zolnikova et al, 2017).…”