when females who carry one good copy and one bad copy of the gene, they are actually affected, whereas males, even when they carry only a bad copy of

the gene, they are not affected.






researchers discover epilespy mutant geneThe World Today - Monday, 12 May , 2008 13:48:00
Reporter: Nance Haxton
ELEANOR HALL: Researchers in Adelaide have discovered the mutant gene responsible for epilepsy in women.

It’s a groundbreaking discovery and the team from the University of Adelaide and the Adelaide Women's and Children's Hospital has had its findings published today in the journal, Nature Genetics.

One of the lead researchers, Dr Leanne Dibbens, has been speaking to Nance Haxton.

LEANNE DIBBENS: We came across a number of families in which only the females in the family suffered from epilepsy and intellectual disability, and it showed a very unusual inheritance pattern in these families, and that led us to look at what the genetic defect in these families was.

NANCE HAXTON: And what did you find?

LEANNE DIBBENS: We found that these families carry different mutations in the one gene, protocadherin 19, and that when females who carry one good copy and one bad copy of the gene, they are actually affected, whereas males, even when they carry only a bad copy of the gene, they are not affected.

NANCE HAXTON: Is the research now looking at why men don't seem to be affected by this condition, even though they carry the gene that's responsible?

LEANNE DIBBENS: Exactly. We're looking at why males aren't affected with this condition, and we have a lead in that we know that there's a related gene on the Y chromosome, and only males carry a Y chromosome, and so we think that this gene is perhaps protecting or rescuing the males in these families from this condition.

NANCE HAXTON: What sort of ramifications would that have once you actually confirm those reasons? Could it be a possible treatment or a prevention for this disorder, and also for epilepsy in a wider range of people?

LEANNE DIBBENS: The most immediate ramification is that we can now offer genetic counselling to these families that suffer ESMR and people can choose to have pre-natal testing if that's what they desire and make decisions on whether they have daughters with this condition.

And the wider implications are that we now know that this gene family is involved in epilepsy and intellectual disability, and so we'll be looking to see whether this gene or other related genes also play a role in these more common disorders.

NANCE HAXTON: So it's really opened up a whole new realm of research into other related disorders, even such as autism or obsessive disorders as well?

LEANNE DIBBENS: That's right. We'll now be looking at larger groups of patients with epilepsy, intellectual disability, and a number of the females affected in these families have autistic features and obsessive features, and so we'll also be looking at patient cohorts with those features.

NANCE HAXTON: The cause of many of these disorders has ultimately been a mystery for a while hasn't it?

LEANNE DIBBENS: That's right. Very little is known about the genetic causes of epilepsy, even the common epilepsies, intellectual disability. We have come a way in understanding causes of that, but in particular, autism and obsessive traits really, very little is known about the genetic causes of those disorders.

NANCE HAXTON: And particularly given that there's a rise in the occurrence of these conditions, that this has certainly come at a very pivotal or interesting time?

LEANNE DIBBENS: That's right. It gives us a chance now to dive in and look at the roles of the types of genes and what roles are playing in the brain and what happens when these processes go wrong, and why it leads to autism and obsessive traits.

NANCE HAXTON: So it could lead to a treatment and a prevention, or would it be really concentrating on one of those two options?

LEANNE DIBBENS: It's always difficult to predict where the research will go and what it would lead to, but we hope that it will enable more genetic counselling and possibly treatments and ultimately prevention. But that's a few years off yet.

ELEANOR HALL: Dr Leanne Dibbens speaking to Nance Haxton in Adelaide.