FRMD7 and cyclic hematopoiesis: Up to now, three loci for X-linked CN have been mapped to Xq26.3-q27.1 (NYS1, OMIM 310700) (Kerrison et al., 1999), Xp11.4-p11.3 (NYS5, OMIM 300589) (Cabot et al., 1999) and Xp22 (NYS6, OMIM 300814) (Liu et al., 2007), and four loci for autosomal dominant congenital nystagmus (AD-CN) have been identified on 6p12 (NYS2, OMIM 164100) (Kerrison et al., 1996), 7p11.2 (NYS3, OMIM 608345) (Klein et al., 1998), 13q31-q33 (NYS4, OMIM 193003) (Ragge et al., 2003) and 1q31.3-q32.1 (NYS7, OMIM 614826) (Xiao et al., 2012).