Eleven out of the 12 sporadic patients with CFEOM1 carried either the c.2860 C > T(p.Arg954Trp) or c.2861G > A(p.Arg954Gln) variant of KIF21A, with one of them (S4) carrying the novel c.3906T > A(p.Asp1302Glu) missense variant of KIF21A. Six of the 11 sporadic patients with bilateral ophthalmoplegia who were diagnosed as having CFEOM3 carried the TUBB3 variants of c.904G > A(p.Ala302Thr), c.1249G > A(p.Asp417Asn), and c.1228G > A(p.Glu410Lys), whereas five of them did not carry either KIF21A or TUBB3 mutations.(Table 1). The gene discussed is KIF21A; the disease is congenital fibrosis of extraocular muscles.