Alpha thalassemia/mental retardation syndrome X-linked (ATRX)
Alpha-thalassemia/mental retardation syndrome X-linked (ATRX) gene is an important genomic marker of gliomas and is either intact (ATRX wild-type) or mutated (ATRX-mutant) and is correlated with other important genomic markers including IDH, 1p19q codeletion and p53 expression 1,2.
ATRX and IDH
Tumours with ATRX mutation (ATRX-mt) are usually associated with IDH positive (mutated) tumours, and when both are present a better prognosis can be expected over tumours with IDH1 positive but intact ATRX (ATRX-wt) 1-3.
ATRX and 1p19q co-deletion
Mutation of ATRX is almost never seen in patients with 1p/19q co-deletion (i.e. they are essentially mutually exclusive). Oligodendrogliomas will, therefore, have intact ATRX and 1p19q co-deletion whereas IDH-mt astrocytomas will usually, but not always, have ATRX-mt but no 1p19q co-deletion 1-3.
ATRX and p53 expression
ATRX-mt is usually associated with increased p53 expression 2.
- 1. Wiestler B, Capper D, Holland-Letz T et-al. ATRX loss refines the classification of anaplastic gliomas and identifies a subgroup of IDH mutant astrocytic tumors with better prognosis. Acta Neuropathol. 2013;126 (3): 443-51. doi:10.1007/s00401-013-1156-z - Pubmed citation
- 2. Leeper HE, Caron AA, Decker PA, Jenkins RB, Lachance DH, Giannini C. IDH mutation, 1p19q codeletion and ATRX loss in WHO grade II gliomas. (2015) Oncotarget. 6 (30): 30295-305. doi:10.18632/oncotarget.4497 - Pubmed
- 3. Azadeh Ebrahimi, Marco Skardelly, Irina Bonzheim, Ines Ott, Helmut Mühleisen, Franziska Eckert, Ghazaleh Tabatabai, Jens Schittenhelm. ATRX immunostaining predicts IDH and H3F3A status in gliomas. (2016) Acta Neuropathologica Communications. 4 (1): 60. doi:10.1186/s40478-016-0331-6 - Pubmed
- WHO classification of CNS tumours
- WHO grading of CNS tumours
- VASARI MRI feature set
- diffuse astrocytoma grading
- grade I:
- grade II:
- grade III
- grade IV:
- glioblastoma vs cerebral metastasis
- radiation-induced gliomas
- gliomatosis cerebri (growth pattern)
- specific locations
- treatment response
- Stupp protocol
- glioma treatment response assessment in clinical trials
- multicentric glioblastoma
- multifocal glioblastoma
- prognostic genetic markers