Figure 2. Deletion in GPR143 identified in subject family with congenital nystagmus. A: Sequence for a normal family member (III: 8 in F re 1), showing the wild type allele. B: Sequence for the proband (III: 22), showing the 37 bp deletion from position 222 to position 258 in exon 1. C: The mutant transcript has a premature termination codon (PTC) located before the normal termination codon (Ter) and is likely to be degraded under the nonsense-mediated mRNA decay (NMD) mechanism.