Genetics Research News
Scientists at the Francis Crick Institute have discovered a set of simple rules that can determine the precision of CRISPR/Cas9 genome editing in human cells. These rules could help to improve the efficiency and safety of genome editing in both the lab and the clinic. By examining the effect of CRISPR genome editing at 1491 target sites across 450 genes in human cells, the team have discovered that the outcomes can be predicted based on simple rules. In this study, researchers have found that the outcome of a particular gene edit depends on the fourth letter from the end of the RNA guide, synthetic molecules made up of about 20 genetic letters (A, T, C, G). “The team discovered that if this letter is an A or a T, there will be a very precise genetic insertion; a C will lead to a relatively precise deletion and a G will lead to many imprecise deletions. Thus, simply avoiding sites containing a G makes genome editing much more predictable.”
What this means for Usher syndrome: Scientists will be able to repair the mutation present in an Usher gene by selecting the correct genetic letter from the end of the RNA guide.
Qing Fu, Mingchu Xu, Xue Chen, Xunlun Sheng, Zhisheng Yuan, Yani Liu, Huajin Li, Zixi Sun, Huiping Li, Lizhu Yang, Keqing Wang, Fangxia Zhang ,Yumei Li, Chen Zhao, Ruifang Sui, Rui Chen.
This study aimed to identify the novel disease-causing gene of a distinct subtype of Usher syndrome.
Zong, Chen, Wu, Liu, Jiang.
Identification of novel mutation in compound heterozygosity in MYO7A gene revealed the genetic origin of Usher syndrome type 2 in this Han family.
Researchers study genotype–phenotype correlations and compared visual prognosis in Usher syndrome type IIa and nonsyndromic RP.
Hidekane Yoshimura, Maiko Miyagawa, Kozo Kumakawa, Shin-ya Nishio, and Shin-ichi Usami.
This first report describing the frequency (1.3–2.2%) of USH1 among non-syndromic deaf children highlights the importance of comprehensive genetic testing for early disease diagnosis.
Maha S. Zaki, Raoul Heller, Michaela Thoenes, Gudrun Nürnberg, Gabi Stern-Schneider, Peter Nürnberg, Srikanth Karnati, Daniel Swan, Ekram Fateen, Kerstin Nagel-Wolfrum, Mostafa I. Mostafa, Holger Thiele, Uwe Wolfrum, Eveline Baumgart-Vogt, Hanno J. Bolz.
This paper found that a family with severe enamel dysplasia that was initially diagnosed with Usher syndrome didn’t have Usher syndrome but instead had mutations in the PEX6 gene.
Lichun Jiang, Xiaofang Liang, Yumei Li, Jing Wang, Jacques Eric Zaneveld, Hui Wang, Shan Xu, Keqing Wang, Binbin Wang, Rui Chen and Ruifang Sui.
Researchers applied next generation sequencing to characterize the mutation spectrum in 67 independent Chinese families with at least one member diagnosed with USH.
Zhai, Jin, Gong, Qu, Zhao, Li
Ophthalmic examinations and audiometric tests were performed to identify the pathogenic mutations in a Chinese pedigree affected with Usher syndrome type II (USH2), which revealed distinguished clinical phenotypes associated with MYO7A and expanded the spectrum of clinical phenotypes of the MYO7A mutations.
Researchers investigated the proportion of exon deletions and duplications in PCDH15 and USH2A in 20 USH1 and 30 USH2 patients from Denmark.
Steele-Stallard, Le Quesne Stabej P, Lenassi E, Luxon LM, Claustres M, Roux AF, Webster AR, Bitner-Glindzicz M..
Screening for duplications, deletions and a common intronic mutation detects 35% of second mutations in patients with USH2A monoallelic mutations on Sanger sequencing. An overview of a study to improve the molecular diagnosis in families with USH2A by screening USH2A for duplications.
A team of researchers from multiple institutions reported a novel type of gene (CIB2) associated with Usher syndrome in the November 2012 issue of Nature Genetics.
Researchers conducting a genetic study of Old Order Amish and Mennonite populations have identified five new genes in which defects cause congenital diseases, including a previously unidentified type of Usher syndrome, type 3B.
"Researchers from the National Institute on Deafness and Other Communication Disorders and the National Eye Institute have now found that an alteration of an Usher gene that causes only deafness can preserve sight and balance when in combination with another alteration of the same gene that causes Usher syndrome, or deaf-blindness. This research has important implications for genetic counselors and may open new prospects for future therapies for vision loss."
EU-funded scientists have succeeded in awakening dormant vision cones, an achievement that may lead to saving millions of people from going blind.
Dr Hanno Bolz says that his team's research challenges the traditional view that USH was inherited as a single gene disorder, and shows that it may result from at least two different genetic mutations.
A new clinical test called the OtoChipTM Test for Hearing Loss and Usher Syndrome was launched by the Laboratory for Molecular Medicine, Partners Healthcare Center for Personalized Genetic Medicine on June 22, 2009. This test sequences ~70,000 bases of DNA across 19 genes involved in hearing loss and Usher syndrome.
It has been discovered that a myosin protein connected to Usher syndrome works differently from many other myosins.