We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
Eurofins Technologies

Download Mobile App




Rare Neurodegenerative Disorders Share DNA Repeat Mutation

By LabMedica International staff writers
Posted on 29 Jul 2019
Print article
Image: Silencing of the FMR1 gene in Fragile X syndrome. FMR1 co-localizes with a rare fragile site, visible here as a gap on the long arms of the X chromosome (Photo courtesy of Wikimedia Commons).
Image: Silencing of the FMR1 gene in Fragile X syndrome. FMR1 co-localizes with a rare fragile site, visible here as a gap on the long arms of the X chromosome (Photo courtesy of Wikimedia Commons).
Genomics researchers have found that at least four rare neurodegenerative diseases result from CGG (cytosine-guanine-guanine) repeat mutations the DNA located in distant, seemingly unrelated areas of the genome.

Noncoding repeat expansions cause various neuromuscular diseases, including myotonic dystrophies, fragile X tremor/ataxia syndrome, some spinocerebellar ataxias, amyotrophic lateral sclerosis, and benign adult familial myoclonic epilepsies.

Inspired by the striking similarities in the clinical and neuroimaging findings between neuronal intranuclear inclusion disease (NIID) and fragile X tremor/ataxia syndrome caused by noncoding CGG repeat expansions in the FMR1 (fragile X mental retardation 1) gene, investigators at the University of Tokyo (Japan) used advanced next-generation genome sequencing and data analysis techniques to search directly for repeat expansion mutations.

Results of the DNA sequencing study identified noncoding CGG repeat expansions in the NBPF19 (Neuroblastoma breakpoint family member 19) gene as the causative mutations for NIID. NIID is a slowly progressive, neurodegenerative disease that may affect any part of the nervous system (central, peripheral, and/or autonomic), as well as various organs. The features of NIID result from the presence of eosinophilic intranuclear inclusions inside neurons and glial cells. Both sporadic and familial cases have been reported. However, specific genes known to cause NIID had not previously been found.

Further prompted by the similarities in the clinical and neuroimaging findings with NIID, the investigators identified similar noncoding CGG repeat expansions in two other diseases: oculopharyngeal myopathy with leukoencephalopathy and oculopharyngodistal myopathy.

"Because the mutations causing the diseases are so similar, in the future, all these patients might benefit from the same treatment," said first author Dr. Hiroyuki Ishiura, an assistant professor at the University of Tokyo Hospital.

The study was published in the July 22, 2019, online edition of the journal Nature Genetics.

Related Links:
University of Tokyo


Print article

Channels

Molecular Diagnostics

view channel
Image: Pre-eclampsia: high magnification micrograph of hypertrophic decidual vasculopathy, as seen in pregnancy-induced hypertension. (Photo courtesy of Wikimedia Commons)

Serum MicroRNAs Predict Likelihood of Pregnant Women Developing Pre-Eclampsia

MicroRNA biomarkers have been identified in the blood of asymptomatic pregnant women that can be used to predict the potential onset of pre-eclampsia. Pre-eclampsia (PE) is a disorder of pregnancy characterized... Read more

Microbiology

view channel
Image: Stenotrophomonas maltophilia colonies on sheep blood agar. Cultivation 48 hours in an aerobic atmosphere, 37 °C (Photo courtesy of microbiologyinpictures).

Global Spread of the Multi-Resistant Pathogen Stenotrophomonas Maltophilia Revealed

Stenotrophomonas maltophilia strains occur in several natural and human associated ecosystems. The bacterium was long regarded as relatively unproblematic, but is now considered to be one of the most feared... Read more
Copyright © 2000-2020 Globetech Media. All rights reserved.