What are the genetic changes related to Pol III-related leukodystrophy ?
Pol III-related leukodystrophy is caused by mutations in the POLR3A or POLR3B gene. These genes provide instructions for making the two largest parts (subunits) of an enzyme called RNA polymerase III. This enzyme is involved in the production (synthesis) of ribonucleic acid (RNA), a chemical cousin of DNA. The RNA polymerase III enzyme attaches (binds) to DNA and synthesizes RNA in accordance with the instructions carried by the DNA, a process called transcription. RNA polymerase III helps synthesize several forms of RNA, including ribosomal RNA (rRNA) and transfer RNA (tRNA). Molecules of rRNA and tRNA assemble protein building blocks (amino acids) into working proteins; this process is essential for the normal functioning and survival of cells.  Researchers suggest that mutations in the POLR3A or POLR3B gene may impair the ability of subunits of the RNA polymerase III enzyme to assemble properly or result in an RNA polymerase III with impaired ability to bind to DNA. Reduced function of the RNA polymerase III molecule likely affects development and function of many parts of the body, including the nervous system and the teeth, but the relationship between POLR3A and POLR3B gene mutations and the specific signs and symptoms of Pol III-related leukodystrophy is unknown.