KIF21A and congenital fibrosis of extraocular muscles: We sequenced all remaining KIF21A exons and intron-exon boundaries in one autosomal dominant CFEOM1 pedigree (LX), four sporadic CFEOM1 probands (NG, RZ, RX, and SY), and all of the CFEOM3 probands, and did not identify any KIF21A mutations.