The POLD3 gene encodes a subunit of the polymerase delta protein complex, that plays a role in the regulation of DNA replication, a mechanism important for the helps cells to copy their DNA, in order to divide. If an alteration occurs at the level of the POLD3 gene, it may cause defects in the mentioned mechanism, leading to a disease. If both copies of the gene are altered (recessive form), the disease tends to appear early and be more severe. Indeed, the disease will manifest in a defect in the immune system leading to severe infections, in addition to hearing loss and delay in neurological development and milestones. If only one copy is altered (dominant form), the main problem may be hearing or balance issues that appear later in life. Genetic testing can find alterations in POLD3, and family members may be offered testing too.
POLD3