Zinc Finger Homeobox Protein 4 (ZFHX4)

The 1p breakpoint was situated approximately 13 Mb distal to the previously reported linkage locus at 1p34.1-p32 identified by linkage as the site of a gene responsible for congenital bilateral isolated ptosis (PTOS1), and did not disrupt the coding sequence, whereas the chromosome 8 breakpoint disrupted a gene homologous to the mouse zfh4 gene.

McMullan et al. (2002) identified 10 exons of the human ZFH4 gene covering approximately 161 kb of DNA; the translocation breakpoint occurred in intron 4. Murine zfh4 codes for a zinc finger homeodomain protein that is a transcription factor expressed in both muscle and nerve tissue. McMullan et al. (2002) proposed that human ZFH4 is a candidate gene for congenital bilateral isolated ptosis.