CHRNA4 and Feingold syndrome: In the review, nine genomic susceptibility traits linked to FS have been described, designated as from FEB1 to FEB9 located on chromosomes 8q13-q21, 19p13.3, 2q23-q24, 5q14-q15, 6q22-q24, 18p11, 21q22, 5q31.1-q33.1 and 3p24.2-p23; furthermore, mutations in the cholinergic receptor nicotinic alpha 4 subunit (CHRNA4) (72), in the voltage-gated sodium channel subunit genes (SCN1A, SCN2A and SCN1B), and in the GABA(A) receptor subunit genes (GABRG2 and GABRD) (75) have been characterized in GEFS+.