Bionomic's epilepsy diagnostic receives positive feedback

Thebarton (SA) epilepsy specialist Bionomics (ASX:BNO, BNOOA; US OTC:BMICY) is getting positive feedback on its newly commercialised DNA diagnostic for severe myoclonic epilepsy of infancy (SMEI).

Leading University of Melbourne epilepsy clinician Assoc Prof Ingrid Scheffer presented a paper to an epilepsy symposium in Melbourne today in which she concluded the test should be considered as an aid to differential diagnosis of SMEI in children who develop epilepsy in the first year of life, but whose brains appear normal in magnetic resonance imaging scans.

SMEI is one of the most severe and therapeutically intractable forms of epilepsy. It has a 15 per cent mortality rate, and is not responsive to standard anticonvulsants like GlaxoSmithKline's Lamictal (lamotrigine).

In about 81 per cent of cases of SMEI, the drug can actually increase the severity of seizures -- and SMEI has a mortality rate of up to 18 per cent.

Bionomic's DNA diagnostic scans for a range of different mutations in the sodium-channel gene, SCN1A, that are variously associated with SMEI, or benign childhood epilepsies. Until now there has been no test that allows neurologists to distinguish between SMEI and less severe forms of childhood epilepsy.

Scheffer was reviewing the results of a clinical study of 239 patients with childhood epilepsy. She said it highlighted the need for accurate diagnosis, given the need to diagnose childhood epilepsies as soon as possible, and the risks of inappropriate prescribing of standard anticonvulsants.

Last September Bionomics licensed the new diagnostic -- its first epilepsy test -- to US neurodiagnostics specialist Athena Diagnostics. They have also licensed the test to Melbourne gene-test biotech Genetic Technologies (ASX:GTG) but Bionomics CEO Dr Deborah Rathjen said it has no figures available yet on its use in Australia, but GTG is mounting an awareness campaign to alert Australasian doctors to the test's availability.

In the US alone, as many as 240,000 children are potential candidates for SMEI testing. Earlier diagnosis and treatment could reduce the severity of the disease later in their lives.

Rathjen said Bionomics has initiated talks with potential licensees for its second epilepsy gene test, for benign childood seizures.

Rathjen said benign childhood seizures can occur as early as the first few days of life, and children typically grow out of them -- suggesting the seizures are not caused by classical mutations.

"Our epilepsy team is generating some very good scientific data at the moment, and has an interesting hypothesis about the cause," Rathjen said.

Most benign seizures involve three potassium ion-channel genes, KCNQ3, and KCNQ2, and SCN2A. Rathjen said the panel test kit being developed by Bionomics will scan the genes in this order, given that KCN3-related seizures are most likely, followed by the other two in descending order.

Bionomics' own epilepsy drug-discovery program has been "moving ahead very nicely'", Rathjen said. "It's a big component of our interest in the field, and we have some very interesting compounds under evaluation.

She said the 'hits' came from the company's screening program of the Walter and Eliza Hall Medical Research Institute's chemical compound library.