Chn1^tm1.1Ece

Exon 3 was replaced with a loxP-flanked exon 3 in which an A to T missense change at position 60 was introduced in exon 3, resulting in a leucine to phenylalanine substitution at amino acid 20 (L20F). An FRT-flanked neomycin selection cassette that was inserted upstream of exon 3 was removed via Flp-mediated recombination. The L20F substitution segregated in a family with Duane retraction syndrome. (J:243785)