FBXL4 and juvenile Huntington disease: High consanguinity rates characteristic of this ethnic group may partially but not completely account for this observation (Inhorn et al., 2009; Tadmouri et al., 2009), and/or alternatively, Arabs may have higher carrier-status rates of FBXL4 mutations compared to other ethnicities, similar to the higher Huntington's disease (i.e., CAG triplet repeat expansion) carrier rates among Europeans compared to other populations as an analogy (Orth et al., 2010).