Table 1.

Results from fluorescent in situ hybridisation (FISH) in fetal testis using two chromosome 21-specific probes (red and green)

		No of signals green/red
Case No/Id	Gest. Age (wks)	2gr/2r	3gr/3r	1gr/1r	2gr/1r	1gr/2r	2gr/3r	3gr/2r	Total no of scored cells
8787	18	3927	-	35*	1	6	2	-	3971
8795	17	2510	-	5	-	2	-	-	2517
5A	14	3294	1#	11**	3	6	-	1	3316
6A	19	2010	-	3	1	22	-	2	2038
Total		11741	1	54	5	36	2	3	11842

*One of these nuclei contained only one chromosome 18 signal and was interpreted as having either monosomy 21 together with monosomy 18 or being haploid; the remaining showing two chromosome 18 signals were recorded as either false negative monosomy 21 (due to somatic pairing) or true monosomy 21 [91,92].

**These nuclei contained two chromosome 18 signals and were also recorded as false negative monosomy 21 (due to somatic pairing) or true monosomy 21[91,92].

#This nucleus had 3 × 18 signals and was recorded as being triploid.