Amniochip detects 150 genetic syndromes from amniotic fluid

14 April 2011

Genetadi Biotech has developed a prenatal diagnostic device that has a diagnostic resolution 100 times greater than common cytogenetic techniques.

The new device, known as Amniochip, is able to detect 150 genetic syndromes using microarray technology to analyse amniotic fluid. The device can produce a result in 48 hours compared to the three weeks it currently takes through conventional kariotype technique.

“This involves currently validated genetic syndromes, including malformations and idiopathic mental deficiency not detected with a conventional kariotype”, explained Dr Silvia Ávila, co-director of Genetadi.

From a clinical perspective, the procedure for the diagnosis does not vary, starting with a standard amniocentesis undertaken by the specialist gynaecologist. “The sample of amniotic liquid does not differ at all from the current amniocentesis procedure”, explained Dr Ávila. “With the Amniochip only 8 or 10 ml of amniotic liquid are necessary in a tube, and which is sent to a laboratory via messenger, exactly as with the usual genetic trials”.

The application of this new technology, through a prescription from the specialist in gynaecology and obstetrics, is especially suitable for pregnant women who require a conventional genetic study (kariotype or FISH). That is, those suspected from ecographs of having malformations, or with positive triple marker, or the over 35s. It is also suitable for couples with a history of miscarriage, or with a family history of genetic syndromes.

In those cases in which the research using this new technology found a result with doubtful clinical significance, “the DNA of the two progenitors were also analysed; in order to discard any family polymorphic alterations”, explained Dr Ávila.

Scientific basis

The new device for enhanced prenatal diagnosis is based on comparative genomic hybridisation (aCGH) microarray technology. Using this technique, the sample to study and a reference are marked with different fluorochromes. The DNA hybridises on a crystal that contains thousands of different segments of human DNA.

The regions selected on the Amniochip belong to regions of the human genome involved in more than 150 already known syndromes. Subsequently, computer software is used to identify the areas of differential hybridisation between the patient and the DNA control, thus indicating the existence of an alteration in its dosage.