IDH-1 Test

The IDH1 is a gene which gives instructions for making an enzyme called isocitrate dehydrogenase 1. Low grade and secondary high grade gliomas (malignant tissue of the glial gland in the nervous system) have mutations in isocitrate dehydrogenase. The mutation analysis of IDH1 helps to diagnose grades II or III of astrocytoma, oligodendroglioma, oligoastrocytoma, or secondary glioblastoma (types of brain tumours). More than 70% of brain tumours have IDH1 mutation. Non brain tumours or other brain tumours seldom have IDH1 mutation. The process of mutation or change in structure of the gene IDH1 leads to the development of brain tumours. It is because of this mutation that the normal enzyme activity is hindered. A range of symptoms that lead to IDH1 mutation analysis test are – memory loss, pain and swelling in the growth or mass, retarded brain function, nausea and vomiting, vision problems and seizures.

Initially, at the onset of symptoms visit your doctor or oncologist without much delay. Discuss all details pertaining to your health, current medication, family medical history, past test reports and lifestyle. Certain medications are known to affect the test result. Therefore, the doctor may advise to discontinue the medication. At first, order for diagnostic tests is given and the IDH1 mutation analysis test is ordered much later. The doctor or oncologist will give you specific instructions leading to the IDH1 mutation analysis test which you must follow diligently. Prior to the sample collection follow the dos and don’ts of the laboratory concerned.

IDH1 mutation analysis test result greatly depends on the adequate sample collection and processing. Treatment should not be based on the test result of IDH1 alone. The treatment or therapy should be considered based on clinical information, additional diagnostic tests and histologic evaluation. A positive result indicates mutation in the IDH1 gene. Diagnosis for Glioma, Chondrosarcoma, Cholangiocarcinoma, Maffucci syndrome, Ollier disease or Primary myelofibrosis should be considered.

The IDH1 mutation analysis test is done in various ways and the sample collection method differs from lab to lab. Sample collection may be done under anaesthetic condition. The tissue sample can be collected from the fresh tumour tissue by biopsy. The tissue sample can be formalin-fixed and paraffin-embedded. The tissue sample can be unstained in slides. Peripheral blood approx. 5 ml is collected in a labelled EDTA tube. Sample from the bone marrow may be collected approx. 2ml in a labelled EDTA tube.