Why is Apert's syndrome so common when mutation rate is so low?

Aug 28, 2007

Aperts syndrome is a condition caused by a mutation that produces fused fingers and toes, and alters cranial development in affected children. It arises spontaneously, but why the mutation that causes this syndrome appears so frequently has been a mystery.

In a new study published this week in the open-access journal PLoS Biology, Jian Qin, Norman Arnheim, and colleagues from University of Southern California provide compelling evidence that suggests the syndrome is perpetuated because the cells carrying the mutation in the testes, and that give rise to sperm, out-replicate normal cells.

The researchers have shown that the single base-pair mutation responsible for over 60% of Aperts cases occurs with such high frequency not because the relevant gene sits at a “mutation hotspot,” but because mutant cells reproduce more frequently then normal cells.

The Aperts mutation occurs in cells with a frequency between 100 and a 1000 times higher than would be predicted given a standard mutation rate. The researchers have developed a new experimental approach that measures the anatomical distribution of the mutant cells in order to investigate the mutation’s origin. They dissected healthy testes to map where the mutations had arisen, and found that mutant cells were clustered together. This distribution cannot be explained by the “hotspot” model, which would place the mutant cells randomly throughout the organ.

Instead, this paper shows that clustered mutations arise because cells carrying the genetic change out-compete normal testes cells and tend to accumulate, producing more sperm that carry the mutation and a higher frequency of transmission.

Source: Public Library of Science

Explore further: Investigators show how immune cells are 'educated' not to attack beneficial bacteria

Related Stories

Ears, grips and fists take on mobile phone user ID

5 hours ago

A research project has been under way to explore a biometric authentication system dubbed Bodyprint, with interesting test results. Bodyprint has been designed to detect users' biometric features using the ...

More than 2,200 confirmed dead in Nepal earthquake

5 hours ago

A powerful aftershock shook Nepal on Sunday, making buildings sway and sending panicked Kathmandu residents running into the streets a day after a massive earthquake left more than 2,200 people dead.

Magnitude 6.7 aftershock hits Nepal, causes panic

6 hours ago

A powerful aftershock shook Nepal on Sunday, making buildings sway and sending panicked Kathmandu residents running into the streets a day after a massive earthquake left at least 1,900 people dead.

Nepal quake: Nearly 1,400 dead, Everest shaken (Update)

16 hours ago

Tens of thousands of people were spending the night in the open under a chilly and thunderous sky after a powerful earthquake devastated Nepal on Saturday, killing nearly 1,400, collapsing modern houses and ...

Russian hackers read Obama emails, report says

16 hours ago

Emails to and from President Barack Obama were read by Russian hackers last year in a breach of the White House's unclassified computer system, The New York Times said Saturday.

Recommended for you

Fat signals control energy levels in the brain

Apr 23, 2015

An enzyme secreted by the body's fat tissue controls energy levels in the brain, according to new research at Washington University School of Medicine in St. Louis. The findings, in mice, underscore a role ...

Human tape worm drug shows promise against MRSA in lab

Apr 23, 2015

A new study provides evidence from lab experiments that a drug already used in people to fight tapeworms might also prove effective against strains of the superbug MRSA, which kills thousands of people a ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.