Table 1.

Chromosomal alterations of ependymoma tumors

		Losses	Comments	Gains	Comments
Mixed populations		6q21	ADM1 and CDK11 underexpression	1q21.1–32.1	Associated with recurrence
		6q23	Poor event-free survival	1q23.3	DUSP12 overexpression, associated with aggressive tumors
		6q24–26	SASH1 and TCP1 underexpression
		9p24.31	Associated with FOXD4 expression, usually expressed in embryonic stem cells	7q34	Found in 38%, codes for ARHGEF5 gene
		10q23.21	Found in 19%, codes for MINPP1	12q12.12	Found in 34%, associated with HOXC4 HOX associated with spinal tumors
		10q26.12	Found in 16%, codes for TACC2
		11q	Inverse relationship with 22q LOH found with mutations in the MEN1 gene at 11q13	1q, 7q, 9q, 12, 13q, 17p, 17q, 20q, 22q	Found in high percentage of ependymomas
		22q	Associated with NF2 mutation
		22q12.3–22q13.3	RAC2, G22P1, MCM5, SULT4A1, FBX7, C22orf2, CBX7, and SBF1 underexpression
		2q, 4q, 5q, 6q, 7q, 9q, 10q, 15q, 16, 17p, 19p, and 21	Less commonly detected
		3q, 6q, 10q, 15, 22	Associated with recent tumors
Ependymoma location	Intracranial	6q, 9, 13		1q
	Infratentorial	17p13.3		9q33–34
	Supratentorial	9p
	Spinal cord	6, 12, 22	Monosomy 22	7	Found in 95% of lesions
	Pediatric spinal	1, 2, 10	Whole chromosome imbalance	7, 9, 11, 18, 20	Whole chromosome imbalance
Pediatric ependymomas		6q	15% of patients, also identified upon tumour relapse	1q	15–50% in pediatric, 8% in adults
				1q21	Highest copy numbers present in SHC1 (41%), S100A11 (31%), and JTB (28%)
				1q21.3–23.1 1q24-q21	High amplification found in both primary and recurrent pediatric patients
				1q21–32	Anaplastic tumors
				1q25	Poor prognosis, abnormalities involving TPR in 38% of ependymomas
		16		1q31.1–31.3 7q, 9p24.3-qter	Found in 58% of patients < 16 years old
		17p	50% of sporadic pediatric ependymomas	9qter	Amplification increased upon subsequent relapse, more frequent in older children
				9q33–34	Found to correlate with recurrence, covering oncogenes Notch1 and TNC
		Monosomy 22	30% of pediatric patients	11q13	Flanks CCND1 oncogene
		22p13	55% of pediatric patients
	Posterior fossa	6, 17, 22	Silencing of HIC–1 on 17p
	Supratentorial Grade III (case study)	1p, 14q	Found in local recurrences and upon tumor metastasis
		1p36	Frequency of loss increased in relation to distance from the site of local recurrence
Ependymoma subtypes	Myxopapillary	1, 10, 22		7	Polysomy found in 13/13 patients
				3, 4, 7, 8, 9, 10, 11, 13, 17q, 18, 20	Simultaneous gains on 9 and 18
	Classic	22	NF2
	–Clear cell	9
	Anaplastic	1p, 9	Implicates cyclin D/CDK4 and p53

NF2 = neurofibromatosis type 2.