UCLA Re­searchers Find Signs of Alzheimer’s Decades Be­fore Ill­ness Strikes

Wellness Update - - Health News -

LOS AN­GE­LES, Calif. – Sci­en­tists at UCLA have dis­cov­ered a new ge­netic risk fac­tor for Alzheimer’s disease by screen­ing peo­ple’s DNA, then us­ing an ad­vanced kind of brain scan to vi­su­al­ize the brain’s con­nec­tions.

Alzheimer’s disease – the com­mon­est cause of de­men­tia in the el­derly – erodes those con­nec­tions, which we rely on to sup­port think­ing, emo­tion, and me­mory. With no known cure, the 20 mil­lion Alzheimer’s suf­fer­ers world­wide lack an ef­fec­tive treat­ment, and we are all at risk - our risk of de­vel­op­ing Alzheimer's dou­bles ev­ery five years af­ter age 65.

The re­searchers dis­cov­ered a com­mon ab­nor­mal­ity in our ge­netic code that in­creases our risk for Alzheimer’s. To find the gene, they used a new method that screens the brain’s con­nec­tions, the wiring or cir­cuitry that com­mu­ni­cates in­for­ma­tion in the brain. Switch­ing off th­ese Alzheimer risk genes – first dis­cov­ered 20 years ago – could stop the dis­or­der in its tracks, or de­lay its on­set by many years.

The re­search ap­pears in the March 4th on­line edi­tion of the Pro­ceed­ings of the Na­tional Academy of Sciences.

“We found a change in our ge­netic code that boosts our risk for Alzheimer’s disease,” said Paul Thompson, se­nior au­thor of the study, a UCLA pro­fes­sor of neu­rol­ogy, and a mem­ber of the UCLA Lab­o­ra­tory of Neuro Imag­ing. “If you have this vari­ant in your DNA, your brain con­nec­tions are weaker. As you get older, faulty brain con­nec­tions in­crease your risk of de­men­tia.”

The re­searchers screened over a thou­sand peo­ple’s DNA, to find, said Thompson, the com­mon “spell­ing er­rors” in the ge­netic code that might heighten risk for disease later in life. In an­other first, each per­son re­ceived a “con­nec­tome scan” as well–a spe­cial type of brain scan that mea­sures water dif­fu­sion in the brain, which al­lows it to map the strength of the brain’s con­nec­tions.

Hun­dreds of com­put­ers, cal­cu­lat­ing for months, sifted through more than 4,000 brain con­nec­tions and the en­tire ge­netic code, com­par­ing con­nec­tion pat­terns in peo­ple with dif­fer­ent ge­netic vari­a­tions. In peo­ple whose ge­netic code dif­fered in one spe­cific gene called SPON1, weaker brain con­nec­tions were found be­tween brain cen­ters con­trol­ling rea­son­ing and emo­tion. The rogue gene also af­fects how se­nile plaques build up in the brain – one of the

main causes of Alzheimer’s.

The new study is the first of its kind to use “con­nec­tome” scans, which re­veal the brain’s cir­cuitry and how in­for­ma­tion is routed around the brain, to dis­cover risk fac­tors for disease. It com­bines th­ese con­nec­tiv­ity scans with ex­ten­sive ge­nomic screen­ing, to pin­point what causes faulty wiring in the brain.

“Much of your risk for disease is writ­ten in your DNA, so the genome is a good place to look for new drug tar­gets,” said Thompson, who founded a re­search net­work in 2009 – known as Project ENIGMA – to pool brain scans and DNA from 26,000 peo­ple world­wide. “If we scan your brain and DNA to­day, we can dis­cover dan­ger­ous genes that will un­der­mine your abil­ity to think and plan, and make you ill in the fu­ture. If we find th­ese genes now, there is a bet­ter chance of new drugs that can switch them off be­fore you or your fam­ily get ill.” De­vel­op­ing new ther­a­peu­tics for Alzheimer’s is a hot area for phar­ma­ceu­ti­cal re­search, he said.

The re­searchers also found that the SPON1 gene can also be ma­nip­u­lated to de­velop new treat­ments for the dev­as­tat­ing disease. When the rogue gene was al­tered in mice, it led to cog­ni­tive im­prove­ments and fewer plaques built up in the brain. Alzheimer’s pa­tients show an ac­cu­mu­la­tion of th­ese se­nile plaques – made of a sticky sub­stance called amy­loid – which kills brain cells, caus­ing ir­re­versible me­mory loss and per­son­al­ity changes.

Screen­ing genomes has led to many new drug tar­gets in the treat­ment of can­cer, heart disease, arthri­tis, and brain dis­or­ders such as epilepsy. But the UCLA team’s ap­proach – screen­ing genomes and brain scans from the same peo­ple – prom­ises a faster and more ef­fi­cient search. “With a brain scan that takes half an hour and a DNA scan from a saliva sam­ple, we can search your genes for fac­tors that help or harm your brain’s con­nec­tions,” said Thompson. “This opens up a new land­scape of dis­cov­ery in med­i­cal sci­ence.” For more in­for­ma­tion, see http:// www.neu­rol­ogy.ucla.edu/

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.