The gene associated with this form is the aquaporin-2 gene. Because the AQP2 gene is carried on a non-sex chromosome, this form of CNDI can affect females as likely as it can males. When this binding occurs, it sets off a cascade of molecular events, which direct AQP2s to kidney collecting duct cell membranes and insert them inside those membranes to make them more water permeable so that the kidney can reabsorb water and concentrate urine. In the remaining minority of cases, the AVPR2 can travel to the cell membrane, but once there it cannot bind with AVP or trigger the next step in the cycle which leads to AQP2s being shuttled to cell membranes to make them more water permeable. The AVPR2 gene, like all genes, has many different parts, and any could be abnormal .
Researchers map out the mutated gene to find the location of the mutations.
This not only provides useful diagnostic information, but also provides a knowledge base for possible genetic therapy . For example, one research group was able, under laboratory conditions, to cover the mutated area of an AVPR2 gene with a non-mutated strip of cultured AVPR2 genetic material, thus restoring some of its functional capacity. Mutations in the AQP2 gene produce AQP2s that are unable to travel to the cell membranes in order to make them more water permeable. So even though the AVPR2 binds with AVP and the molecular sequence is initiated, the AQP2s, largely due to being misformed, aren't allowed to travel to their work site, and the result is that the kidney cells can't reabsorb water and concentrate urine. Early diagnosis can initiate proper and timely treatment, thus avoiding the possible consequences listed earlier.