Table 4. Total number of paediatric (⩽16 years) MGCTs analysed by conventional cytogenetic techniques reported in the literature to date, with relative frequencies of iso(12p) by age range.

	Age < 5 years		Age ⩾5 <16 years
	Case mix	iso(12p)	Case mix	iso(12p)
Oosterhuis et al (1988)	1 (1 YST)	0	0	0
Speleman et al (1990)	0	0	1 (1 Mixed)	1
Shen et al (1990)	0	0	1 (1 Mixed)	0 (but 4 copies of chromosome 12)
Albrecht et al (1993)	0	0	1 (1 Germinoma)	0 (but extra 12p material)
de Bruin et al (1994)	0	0	1 (1 Mixed)	1
Perlman et al (1994)	6 (6 YST)	0	0	0
Stock et al (1994)	6 (2 EC, 2 YST, 2 Mixed)	1	5 (2 DG, 1 Mixed, 2 SE)	1
Jenderny et al (1995)	4 (4 YST)	4a	2 (2 YST)	1a
Stock et al (1995)	8 (6 YST, 2 EC)	1	5 (2 DG, 2 Mixed, 1 EC)	2
Sainati et al (1996)	1 (1 EC)	0	0	0
Lemos et al (1998)	1 (1 Geminoma)	0	0	0
Losi et al. (1994)	0	0	1 (1 Mixed)	1
Bussey et al (1999)	21 (11 YST, 7 Mixed, 3 UK)	0	23 (16 Mixed, 3 YST, 2 UK, 1 Germinoma, 1 Malignant teratoma)	2+2 other 12p structural abnormalities
Okada et al (2002)	0	0	10 (6 Germinoma, 3 Mixed, 1 YST)	2
Van Ecten et al (2002)	3 (3 YST)	0	0	0
Poulos et al (2006)	1 (1 Mixed)	1	2 (2 Mixed)	2
Total	52	7 (13.5%)	52	13 (25%)+4 others

Case mix includes mixed malignant germ cell tumour (mixed), yolk sac tumour (YST), embryonal carcinoma (EC), dysgerminoma (DG), seminoma (SE) and unknown germ cell tumour (UK).

^aGain of chromosome 12 by in situ hybridisation – iso(12p) status unclear, but one case in each age range almost certainly iso(12p).