Mutant gene causes epilepsy, intellectual disability in women

May 12, 2008

A mutated gene has been discovered as the key behind epilepsy and mental retardation specific to women, thanks to new research at Adelaide’s Women’s & Children’s Hospital and the University of Adelaide, Australia.

The world-first discovery, published today in Nature Genetics, shows that although men carry the ‘bad’ gene, only women are affected.

The research has been led by Dr Leanne Dibbens and Associate Professor Jozef Gecz from the Department of Genetic Medicine, Women’s & Children’s Hospital, and the Discipline of Paediatrics at the University of Adelaide. The discovery is a result of a major international collaboration involving the Sanger Institute in Cambridge (UK), Wellcome Trust (UK) and many other collaborators in Australia, the United States, Ireland and Israel.

Their work has linked, for the first time, a large family of genes known as protocadherins with a condition known as “epilepsy and mental retardation limited to females” (EFMR).

Although a relatively uncommon disorder, the condition is hereditary, with successive generations of women affected. In just one of seven families studied across the world, 23 women were affected by the disorder across five generations. This discovery will now enable such families to benefit from genetic counselling, including screening for the genetic mutation at pregnancy.

“This is the first time this type of gene has been found to be involved in epilepsy,” Dr Dibbens says.

“One of the most important discoveries we’ve made is that women in families affected by EFMR carry both a 'good' gene and a 'bad' (mutated) gene, while the men carry only the bad gene. For some reason, the men remain unaffected by the condition,” Dr Dibbens says.

“We suspect this may have something to do with the male Y chromosome, but more research will be needed to find out exactly how or why.”

Dr Dibbens says the gene involved in this discovery is important for cell-to-cell communication in the brain, and could also hold the key to better understanding related issues, such as autism and obsessive disorders.

“With 100 related proteins involved in this gene family, this study could lead to many new areas of research, with the need to understand the role and function of each protein,” she says.

Clinically, the disorder EFMR was first described more than 10 years ago, but the cause of EFMR has been unknown until now. Why females rather males are affected – as is usual for X chromosome associated disorders – makes this a unique disorder among the epilepsies and mental retardations.

For this study, seven families were studied in Australia, the United States, Israel and Ireland. The genetic mutation was discovered in each family.

Crucial to this research was access to state-of-the-art technological support including the sequencing of 737 genes on the X chromosome, which was conducted by collaborators at the Wellcome Trust Sanger Institute in the UK.

Source: University of Adelaide

Explore further: Novel gene variants found in a difficult childhood immune disorder

add to favorites email to friend print save as pdf

Related Stories

Living in the genetic comfort zone

5 hours ago

The information encoded in the DNA of an organism is not sufficient to determine the expression pattern of genes. This fact has been known even before the discovery of epigenetics, which refers to external ...

'Bright spot' on Ceres has dimmer companion

6 hours ago

Dwarf planet Ceres continues to puzzle scientists as NASA's Dawn spacecraft gets closer to being captured into orbit around the object. The latest images from Dawn, taken nearly 29,000 miles (46,000 kilometers) ...

Key facts on US 'open Internet' regulation

6 hours ago

A landmark ruling by the US Federal Communications Commission seeks to enshrine the notion of an "open Internet," or "net neutrality." Here are key points:

Spotify deals with random shuffle and we mortals

6 hours ago

How do we mortals perceive random sequences? An entry in the question-and-answer site Quora focused on a question involving a music-streaming service Spotify. That question signifies how we perceive what ...

Recommended for you

Exploring the genetic origins of autism

Feb 25, 2015

The geneticist Sébastien Jacquemont is the new holder of the Canada Research Chair in Genetics of Neurodevelopmental Disorders and Associated Dysregulation in Energy Balance at the University of Montreal. He moved to the ...

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.