Fifteen new mutations and two new deletions have been identified in three genes that encode for type 4 collagen in Alport syndrome patients.
These new findings are now added to the already known spectrum of mutations associated with Alport syndrome and may help to improve disease prognosis as a result of early diagnosis by combining genetic testing with clinical and symptomatic assessment.
The study, “Novel mutations in COL4A3, COL4A4, and COL4A5 in Chinese patients with Alport Syndrome,” was published in PLOS ONE.
Collagen plays an important role in maintaining the structure and function of several tissues in the body. Type 4 collagen is key to ensure the structural integrity of glomeruli, which are capillaries that have formed a network to make sure blood is filtered in the kidneys.
The correct formation of collagen is fundamental for the proper function of the glomeruli in kidneys. Alport patients have a mutation in the gene that carries information for collagen formation, leading to a deficit of collagen and, as a result, to an insufficient function of the glomeruli, causing kidney problems in these patients.
This study enrolled 20 Alport patients from unrelated Chinese families; 18 were men and two were women. The authors used blood samples collected from the participants to sequence their genetic material and search for mutations in three specific genes that carry the information for the formation of collagen.
Researchers found that, of all the mutations analyzed in the genetic material of the patients, 15 had never been identified before, six were already known mutations associated with Alport syndrome, and two were not yet described depletions of part of the genetic information for collagen formation.
This new data will now be added to the already long list of 1,304 mutations in the three genes for collagen formation that relate to Alport syndrome.
Results also show that 16 of the patients inherited their mutations in the X chromosome from one of the parents, while the remaining four participants inherited mutations from both their parents.