Assignment of the Human Gene for the Water Channel of Renal Collecting Duct Aquaporin 2 (AQP2) to Chromosome 12 Region q12-->q13
|Title:||Assignment of the Human Gene for the Water Channel of Renal Collecting Duct Aquaporin 2 (AQP2) to Chromosome 12 Region q12-->q13|
|Authors:||Deen, Peter M.T.; Weghuis, D.O.; Sinke, R.J.; Geurts van Kessel, A.; Wieringa, Be; van Os, Carel|
|Publisher:||Cytogenetics and Cell Genetics|
This translation by the NDI Foundation is to assist the lay reader. To provide a clear, accessible interpretation of the original article, we eliminated or simplified some technical detail and complicated scientific language. We concentrated our translation on those aspects of the article dealing directly with NDI. The NDI Foundation thanks the researchers for their work toward understanding and more effectively treating this disorder.
© Copyright NDI Foundation 2007 (JC)
The disorder, nephrogenic diabetes insipidus (NDI) is characterized by the kidney's inability to respond to the antidiuretic hormone, arginine vasopressin (AVP). Because it does not respond to AVP, the kidney is unable to concentrate urine by reabsorbing the body water flowing through the kidney collecting duct. As a result, the NDI patient experiences polyuria (chronic passage of large volumes of urine) and polydipsia (chronic, excessive thirst).
NDI may either be acquired or inherited. The inherited forms of NDI may be either inherited in an X-linked recessive or an autosomal recessive pattern. This indicates that there are two different genes that, when mutated, cause NDI: one that is located on the X chromosome, and one that is located on one of the 22 autosomal (non-sex) chromosomes.
The gene responsible for X-linked NDI is the vasopressin-2 (V2R) gene. The gene researchers suspect is responsible for the autosomal recessive form is the aquaporin-2 (AQP2) gene, which codes for a water channel in the collecting duct that is regulated by AVP. But before this can be confirmed researchers must determine whether the AQP2 gene is located on one of the 22 autosomal chromosomes and, if yes, at which specific location.
Deen, et al., analyzed the hybridizations of chromosomal DNA from a panel of 25 different human-mouse hybrid cell lines and found the AQP2 gene was located on chromosome 12. Additionally, in situ hybridization of the AQP2 gene with human chromosomes, showed that the AQP2 gene was located in region q12-q13 on chromosome 12. Therefore, mutations in the human AQP2 gene could be responsible for the autosomal recessive form of NDI.