Test Details: Immunohistochemical testing is carried out on biopsy/resected tissue specimen. This testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody .ATRX is also known as ATP-dependent helicase ATRX, X-linked helicase II, or X-linked nuclear protein (XNP) is a protein that in humans is encoded by the ATRX gene. Mutations of the ATRX gene are associated with an X-linked mental retardation (XLMR) syndrome most often accompanied by alpha-thalassemia (ATRX) syndrome. Studies showed , loss of ATRX expression is seen in 45% of anaplastic astrocytomas, 27% of anaplastic oligoastrocytomas, 10% of anaplastic oligodendrogliomas. In grades II/III gliomas, most ATRX‐ loss cases had IDH1/2 mutations. ATRX mutations accompanied by an alternative lengthening of telomeres (ALT), impacted favourable survival of patients with astrocytic tumours