Researchers have successfully solved part of this puzzle through a detailed genetic study. The discovery began with an American family consisting of a father and eight children suffering from blindness and other hereditary diseases. Susan Roosing, a molecular geneticist at Radboudumc, said: 'They came to us asking about the cause of their condition. Is there a single gene responsible or several genes?' Initial analyses showed no defects in the known disease-causing genes, so the team performed a full DNA analysis of the parents and children. Researchers from Radboudumc and the University of Basel have identified new genetic causes of inherited blindness. The researchers found that the mutation in the American family disrupts a critical regulatory mechanism in the retina, causing blindness. The team expanded the scope of the research in collaboration with researchers from the University of Basel and international colleagues, analyzing the DNA of 5,000 patients with unknown causes of retinitis pigmentosa. This analysis explained some other cases but not retinitis pigmentosa, prompting the team to search for a new cause. The disease usually starts with night blindness, followed by a narrowing of the visual field, and some patients may lose their sight completely as the condition progresses. Despite knowing more than a hundred genes that cause the disease, the genetic cause remains unknown in 30 to 50% of patients even after extensive DNA testing. These variants now account for about 1.4% of undiagnosed cases worldwide. Kim Roordenberg, a genetics researcher, said: 'We have not only discovered a new cause of blindness but have also shown that non-protein-coding parts of DNA are of great importance.' This finding suggests that looking beyond protein-coding genes may be necessary to understand hereditary diseases. This led to the discovery of four additional similar genes, enabling a molecular diagnosis for 153 individuals from 67 families. A new study has shown that changes in certain parts of DNA play a role in the processing of genetic information and can lead to retinitis pigmentosa. Approximately one person in 5,000 worldwide suffers from retinitis pigmentosa, which often leads to a narrowing of the visual field and vision loss. Retinitis pigmentosa is a disorder in which the rod and cone cells in the retina gradually deteriorate. Ultimately, they discovered a mutation in the RNU4-2 gene. This gene produces a ribonucleic acid (RNA) that is not translated into a protein but plays a vital role in modifying genetic information before protein production.
