Refinement of the physical location and the genomic characterization of the CRSP2 (EXLM1) gene on Xp11.4

DNA Seq. 2003 Apr;14(2):123-7. doi: 10.1080/1042517021000056952.


In the course of our search for the gene responsible for X-linked cone-rod dystrophy (COD1), we constructed a physical map and contig (encompassing the region between DXS556 and DXS228), and identified sequences showing homologies to the expressed sequence tags (ESTs) that matched CRSP2 (EXLM1) transcript. We confirmed the expression of the CRSP2 gene in the retina and refined its exact genomic location between DXS1368 and DXS993. We demonstrated that the entire transcript is encoded within 31 exons. Primers were designed for mutation analysis of the exons by direct sequencing of PCR products from genomic DNA, and revealed no mutations in COD1 families. We subsequently excluded CRSP2 as a candidate for COD1 by demonstrating the causative mutations in the RPGR. However, due to its expression in different tissues and its contribution to transcriptional regulation, CRSP2 may be a candidate for other diseases that map to this region of the X chromosome.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Chromosome Mapping
  • Chromosomes, Human, X*
  • Contig Mapping
  • DNA Mutational Analysis
  • DNA Primers / metabolism
  • DNA, Complementary / metabolism
  • Exons
  • Expressed Sequence Tags
  • Humans
  • Mediator Complex
  • Models, Genetic
  • Open Reading Frames / genetics
  • RNA, Messenger / metabolism
  • Retina / metabolism
  • Retinitis Pigmentosa / genetics
  • Trans-Activators / genetics*
  • Transcription, Genetic


  • CRSP protein, human
  • DNA Primers
  • DNA, Complementary
  • MED14 protein, human
  • Mediator Complex
  • RNA, Messenger
  • Trans-Activators