Efforts from four research teams in France (team led by Giovanni Stévanin, Inserm unit 975 “Centre of research into neuroscience at the Pitié-Salpêtrière”), theUS,Taiwanand theNetherlands, have identified the gene responsible for a hereditary neurological disorder affecting the cerebellum: type SCA22 spinocerebellar ataxia.
Almost ten years of work had previously not resulted in identifying the genes responsible for this illness.
The four research teams used a combination of genetic linkage analysis applied to the entire genome and new sequencing technology of the exome in four different patient groups. The four studies resulted in identifying three different mutations in the KCND3 gene that encodes a potassium channel. Electrophysiological studies demonstrated that the mutations led to disturbance in neuronal excitability.
For the researchers, “This study offers confirmation diagnosis for patients in these groups and can be used to target the research for treatments in these specific cases”.
This study also demonstrates the benefits of analyzing the exome, including in small groups, which have not been studied in any depth until now.
These results were published on line in the Annals of neurology review.
Mutations in KCND3 cause spinocerebellar ataxia type 22 Yi-chung Lee*, Alexandra Durr*, Karen Majczenko*, Yen-hua Huang, Yu-chao Liu BS, Cheng-chang Lien, Pei-chien Tsai PhD, Yaeko Ichikawa, Jun Goto, Marie-Lorraine Monin, Jun Z. Li, Ming-yi Chung, Emeline Mundwiller, Vikram Shakkottai, Tze-tze Liu, Christelle Tesson, Yi-chun Lu, Alexis Brice, Shoji Tsuji, Margit Burmeister#, Giovanni Stevanin# and Bing-wen Soong# (*co-first authors, #co-last authors). Annals of Neurology