IFT81 is a 676 amino acid protein that is present at high levels in testis and is moderately expressed in heart, liver, ovary, pancreas, kidney and skeletal muscle. Existing as three alternatively spliced isoforms, two of which are designated CDV-1 and CDV-1R, IFT81 plays a role in testicular development and spermatogenesis and may also be involved in cardiac hypertrophy caused by carnitine deficiency. The gene encoding IFT81 maps to human chromosome 12, which encodes over 1,100 genes and comprises approximately 4.5% of the human genome. Chromosome 12 is associated with a variety of diseases and afflictions, including hypochondrogenesis, achondrogenesis, Kniest dysplasia, Noonan syndrome and Trisomy 12p, which causes facial developmental defects and seizure disorders.