Identification of a cartilage intermediate layer protein (CILP) gene associated with lumbar disc disease (LDD)


The Laboratory for Bone and Joint Diseases has found that a gene encoding cartilage intermediate layer protein (CILP) is one of the susceptibility genes forlumbar disc disease (LDD).
LDD is caused by degeneration of intervertebral discs of the lumbar spine. LDD-caused low back pain and unilateral leg pain can make life difficult for many people; however, the etiology and pathogenesis of LDD remains largely unknown. Using a case-control association study of SNPs, CILP was identified as one of the genes associated with LDD.
CILP (found in cartilage matrix) inhibits TGF-ß, a principal growth factor for chondrogenesis. Inhibition of TGF-ß function is related to LDD susceptibility. Individuals with an SNP in their CILP gene have 1.6 times the risk of developing LDD. The CILP protein resulting from the SNP has a stronger inhibitory effect on TGF- ß.
These research results are the world’s first discovery of a causal factor for LDD at the gene and protein levels with convincing evidence. It is expected that identification of the mechanisms maintaining intervertebral discs will lead to development of breakthrough treatments and new medicines for LDD.
The research results were published in the online version of the U.S. science journal Nature Genetics on May 2, 2005.