What genes are involved in typical (Class 1) 1q21.1 deletions and duplications?
In the “typical” 1q21.1 deletion or duplication, there are about 20 genes that are missing (deleted) or extra (duplicated). Some have not been researched at all, and have been left out of the summary.
These genes that begin with “NBPF” have been found in children with features like macrocephaly, autism, schizophrenia, intellectual disability, congenital heart disease, neuroblastoma, and problems with the kidney and urinary tract. This gene family contains many pseudogenes (see definition below).
- PRKAB2 – Important for regulating energy in cells (involved in making fatty acids and cholesterol for cells)
- FMO5 – Two missing copies of this gene are associated with a condition called “Trimethylaminuria,” which causes an unusual odor.
- GJA8 – Important for the growth of specific cells in the eye called “lens fiber cells.” Missing copies of this gene (deletions) can result in an increased chance for cataracts.
- CHD1L – Important in chromatin remodeling (this is like “behind-the-scenes” work with preparing DNA to be used, read, or copied).
- BCL9 – The function of this gene is unknown when it is deleted or duplicated in a person. Errors in this gene have been found in patients with B-cell acute lymphoblastic leukemia. The errors with this gene are thought to happen in a person’s cancer cells (which are usually genetically different than the cells in the rest of a person’s body. We do not think that people who have deletions or duplications of this gene are at an increased risk for leukemia.
What is a pseudogene?
Pseudogenes are thought to be inactive gene. (“Pseudo” means “fake” in Latin.) They are similar to normal genes, but are not functional. The information or “genetic sequence” of a pseudogene is often similar to another gene that has a job in the body. Pseudogenes arise because of copying errors that have happened in the past. They are actually copies of other functioning genes, that were incorporated into a person’s DNA a very long time ago, but no longer have a job. Pseudogenes are considered “non-coding” DNA.