Featured Research

from universities, journals, and other organizations

Devastating 'founder effect' genetic disorder raced to defective mitochondria in cerebellar neurons

Date:
December 9, 2011
Source:
American Society for Cell Biology
Summary:
Defective mitochondria, the energy-producing powerhouses of the cell, trigger an inherited neurodegenerative disorder that first shows itself in toddlers just as they are beginning to walk, Canadian scientists report.

Defective mitochondria, the energy-producing powerhouses of the cell, trigger an inherited neurodegenerative disorder that first shows itself in toddlers just as they are beginning to walk, Canadian scientists reported at the American Society for Cell Biology Annual Meeting, Dec. 6, in Denver.

The disorder, Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS), was first identified in the late 1970s among the descendants of a small population of 17th century French immigrants who settled in the Charlevoix and the Saguenay River regions northeast of Quebec City.

At the ASCB meeting, a team of researchers at the Montreal Neurological Institute at McGill University and the Centre Hospitalier de l'Universitι Montrιal (CHUM), reported that they had traced the cellular basis of ARSACS to disruptions in neuronal mitochondria, particularly in Purkinje cells in the cerebellum.

The identification of defective mitochondria as the cellular mechanism underlying ARSACS follows a series of discoveries that were made possible by the relatively high incidence (one in 1,500 to 2,000 in this Canadian population) of ARSACS and detailed genealogical records on this population.

In 2000, scientists pinpointed the genetic mutation responsible for the disease, and subsequently identified the massive 4,579 amino acid protein, named sacsin, coded by the ARSACS gene.

Over 100 separate mutations have been found in people diagnosed with ARSACS in Japan, Turkey, and across Western Europe.

The researchers, led by Peter McPherson, Ph.D., Paul Chapple, Ph.D., and Bernard Brais, M.D., Ph.D., developed a genetically modified mouse model that could not produce the normal sacsin protein.

The sacsin-knockout mice developed neurons with abnormally shaped and poorly functioning mitochondria, the organelles that act as energy-producing powerhouses in cells.

This disruption led to the eventual death of individual neurons within the Purkinje layer of the cerebellum. The same result occurred when the scientists repeated the experiment in a laboratory culture of neurons in which sacsin was knocked down by a lentiviral system driving inhibitory RNA.

McPherson said that at the cellular level, ARSACS is similar to such neurodegenerative diseases as Huntington's, Parkinson's, and Alzheimer's.

ARSACS has minimal effects on cognitive functions but instead concentrates its damage within the cerebellum, the center of muscle coordination at the base of the brain. The unsteadiness of gait, or ataxia, in children with ARSACS worsens, progressing through a growing list of difficulties with coordination, muscle wasting, uncontrolled eye movement, retinal streaks, peripheral neuropathy, and impaired speech. By the age of 40, most ARSACs patients must use wheelchairs.


Story Source:

The above story is based on materials provided by American Society for Cell Biology. Note: Materials may be edited for content and length.


Cite This Page:

American Society for Cell Biology. "Devastating 'founder effect' genetic disorder raced to defective mitochondria in cerebellar neurons." ScienceDaily. ScienceDaily, 9 December 2011. <www.sciencedaily.com/releases/2011/12/111206131444.htm>.
American Society for Cell Biology. (2011, December 9). Devastating 'founder effect' genetic disorder raced to defective mitochondria in cerebellar neurons. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2011/12/111206131444.htm
American Society for Cell Biology. "Devastating 'founder effect' genetic disorder raced to defective mitochondria in cerebellar neurons." ScienceDaily. www.sciencedaily.com/releases/2011/12/111206131444.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Stone Fruit Listeria Scare Causes Sweeping Recall

Stone Fruit Listeria Scare Causes Sweeping Recall

Newsy (July 22, 2014) — The Wawona Packing Company has issued a voluntary recall on the stone fruit it distributes due to a possible Listeria outbreak. Video provided by Newsy
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) — The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com
CDC Head Concerned About a Post-Antibiotic Era

CDC Head Concerned About a Post-Antibiotic Era

AP (July 22, 2014) — Sounding alarms about the growing threat of antibiotic resistance, CDC Director Tom Frieden warned Tuesday if the global community does not confront the problem soon, the world will be living in a devastating post-antibiotic era. (July 22) Video provided by AP
Powered by NewsLook.com
Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) — Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins