Gene Related To Head Size Also Linked To Parkinson’s Disease And Dementia

DOHA–(ENEWSPF)–April 17, 2012 — A physician and geneticist at Weill Cornell Medical College in Qatar (WCMC-Q) has had his research into head size published in the prestigious journal Nature Genetics.

Dr. Dennis Mook-Kanamori’s research identified genes that influence head size and are related to Parkinson’s disease and dementia.

Dr. Mook-Kanamori, was one of the lead authors on the paper that found three new gene variants related to the circumference of a person’s head. One of those genes was also known to be associated with both Parkinson’s and dementia.

Dr. Dennis Mook-Kanamori

“We know that the measurement of the circumference of the head is linked to all kinds of cognitive and neurological variability. There are a lot of diseases that come with a large or small head so we were trying to find genes that influence head size, said Dr. Mook-Kanamori.

“In a large international collaborative effort, we measured the head circumference of 10,000 children aged 18 months old and scanned their genomes to see if there was a gene related to head size.”

The researchers involved in the study found three genes. The first two were related to adult height but the third one found was also known — from previous research — to be linked to Parkinson’s disease and dementia.

At the same time an MRI study was being conducted on intra-cranial volume (also in Nature Genetics this month). Researchers involved with that study, including Dr. Mook-Kanamori, measured the intra-cranial volume of 8,000 people and found one gene associated with it. It was the same gene linked to both head circumference and Parkinson’s. The research sheds new light on what may cause dementia and Parkinson’s disease although Dr. Mook-Kanamori cautioned about jumping to rash conclusions.

Dr. Dennis Mook-Kanamori

He said: “We have to be careful as all we are showing is that this gene is related to head circumference and intra-cranial volume and other researchers have said it’s related to Parkinson’s and dementia. But you could hypothesize that this gene could somehow be a link between early head growth and neuro-degenerative diseases.”

“This gene only explains less than one percent of the variation in growth, but yes it’s exciting, there’s new biology and if we find what’s going on we could find some new pharmaceutical methods to treat Parkinson’s.

“Although it’s only responsible for a small variation in head size it still may give you an idea of why people get dementia and Parkinson’s. It’s the beginning, it’s the first step to understanding biological pathways.”

The study is the third Dr. Mook-Kanamori has been involved in which has been published in Nature Genetics. He was part of a team led by Dr. Struan F.A. Grant, associate director of the Center for Applied Genomics at The Children’s Hospital of Philadelphia, which discovered two new gene variants that increase the risk of childhood obesity. That research was published online by Nature Genetics at the beginning of April.

Dr. Mook-Kanamori said: “This was the first study looking at the genetics of childhood obesity and we found that a lot of the genes involved in adult obesity were also involved with children. However, we also found two new genes that were specifically related to childhood obesity. “They seem to affect the gut although we don’t know for sure. The great thing is that it’s new biology.

“Now the challenge is to go into the lab and find out what these genes are really doing. That is the role for places like Weill Cornell Medical College in Qatar, using animal models to find out how these genes work.”

But Dr. Mook-Kanamori stressed that these genes were not the cause of childhood obesity.

“These two genes explain less than one percent of childhood obesity,” he said.

“It’s proven, it’s robust and each study showed the same but the effect is really minimal.”