New genetic deafness syndrome identified

Mar 09, 2011

Ten years ago, scientists seeking to understand how a certain type of feature on a cell called an L-type calcium channel worked created a knockout mouse missing both copies of the CACNA1D gene.

The CACNA1D gene makes a that lets calcium flow into a cell, transmitting important instructions from other cells. The lived a normal life span, but their hearts beat slowly and arrhythmically. They were also completely deaf.

Today at the 55th Annual Biophysical Society Meeting in Baltimore, an international team lead by Hanno Bolz of the University of Cologne in Germany has identified a mutation on the CACNA1D gene affecting two families in Pakistan. The altered gene adds one extra amino acid to the middle of the protein, which is more than 2,000 in length.

The result: family members with two copies of the mutated gene are not only deaf but also have an irregular heart beat. "Their heart beats slowly, dropping below 30 beats a minute during sleep," says Joerg Striessnig, professor at the University of Innsbruck in Austria and one of the senior study authors.

The researchers analyzed the family's mutation and determined that it does not destroy the protein, says Striessnig. "Normally, part of the protein acts like a hinge to open the once the cell gets stimulated. The mutated protein still sits in the cell's surface membrane where it should be, but the hinge does not open the channel," he says. "It's not only interesting for medicine but also for understanding how these channels work as molecular machines ."

Explore further: First genetic link discovered to difficult-to-diagnose breast cancer sub-type

More information: The presentation, "Biophysical Properties of a Human Disease-Causing Mutation in Cav1.3 L-type Calcium Channels" by Andreas Lieb et al is at 10:30 a.m. on Wednesday, March 9, 2011 in the Baltimore Convention Center, Hall C. Abstract: tinyurl.com/4h4y5lk

Provided by American Institute of Physics

not rated yet
add to favorites email to friend print save as pdf

Related Stories

Gene called flower missing link in vesicle uptake in neurons

Sep 03, 2009

As part of the intricate ballet of synaptic transmission from one neuron to the next, tiny vesicles - bubbles containing the chemical neurotransmitters that make information exchange possible -- travel to the tip of neurons ...

Gene identified for sudden unexpected death in epilepsy

Apr 13, 2010

A mutation in a brain protein gene may trigger irregular heart beat and sudden death in people with epilepsy, according to new research in the April 14 issue of The Journal of Neuroscience. People with epilep ...

Rare disease provides clues about enzyme role in arrhythmias

Dec 11, 2008

A University of Iowa study provides insight into a calcium-sensing enzyme already known to play a role in irregular heartbeats and other critical functions. The researchers showed that the enzyme, calmodulin kinase II (CaM ...

Understanding night blindness and calcium

Apr 01, 2010

Congenital stationary night blindness, an inherited condition that affects one's ability to see in the dark, is caused by a mutation in a calcium channel protein that shuttles calcium into and out of cells. Now, researchers ...

Protein identified that helps heart muscle contract

Feb 16, 2010

UCSF researchers have discovered that a protein called B1N1 is necessary for the heart to contract. The findings, published in the Feb. 16 issue of the open access journal PLoS Biology, shed light not only on what makes ...

Recommended for you

Refining the language for chromosomes

Apr 17, 2014

When talking about genetic abnormalities at the DNA level that occur when chromosomes swap, delete or add parts, there is an evolving communication gap both in the science and medical worlds, leading to inconsistencies in ...

Down's chromosome cause genome-wide disruption

Apr 16, 2014

The extra copy of Chromosome 21 that causes Down's syndrome throws a spanner into the workings of all the other chromosomes as well, said a study published Wednesday that surprised its authors.

User comments : 0

More news stories

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Study says we're over the hill at 24

(Medical Xpress)—It's a hard pill to swallow, but if you're over 24 years of age you've already reached your peak in terms of your cognitive motor performance, according to a new Simon Fraser University study.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.