Table 4

Frequency of different haplotypes within single linkage disequilibrium (LD) blocks, and analysis of association between each LD block haplotype and congenital heart defects in deletion patients

LD block	Haplotype	Controls n = 192 chromosomes*	P1, n = 78	P2, n = 96	HP, n = 123	NP, n = 51	χ² HP v NP
*Frequency of different haplotypes within single LD blocks in 96 healthy, dizygous controls; χ² analysis showed no significant association between single haplotypes or haplotype combinations (I-IV) and the presence of heart defects in 22q11.2 deletion patients. Values of χ² could not be determined for variations (4) and (5) in combined haplotypes I-IV, as the expected cell frequencies are less than five. However, there is obviously no significant difference in frequency. Differences of haplotype frequencies between controls, P1 and P2, respectively are also not significant. Numbering of haplotypes is as in fig 3 for LD block III and IV, and as in fig 1 for combined LD blocks.
HP, combined 22q11.2 deletion patients with congenital heart defects from Germany and Belgium; NP, combined 22q11.2 deletion patients without relevant heart defects from Germany and Belgium; P1, 22q11.2 deletion patients from Germany; P2, 22q11.2 deletion patients from Belgium.
III	1	0.48	0.59	0.52	70 = 0.57	26 = 0.51	0.51 (p = 0.475)
	2	0.27	0.19	0.27	25 = 0.20	16 = 0.31	2.44 (p = 0.118)
	3	0.21	0.21	0.21	27 = 0.22	9 = 0.18	0.41 (p = 0.522)
IV	1	0.53	0.63	0.57	74 = 0.60	30 = 0.59	0.18 (p = 0.671)
	2	0.30	0.27	0.31	33 = 0.27	18 = 0.35	1.25 (p = 0.264)
	3	0.16	0.10	0.11	16 = 0.13	3 = 0.06	1.88 (p = 0.170)
I-IV	(1)	0.34	0.35	0.27	41 = 0.34	11 = 0.22	2. 38 (p = 0.123)
	(2)	0.14	0.26	0.21	25 = 0.20	15 = 0.29	1.68 (p = 0.195)
	(3)	0.21	0.17	0.20	20 = 0.16	12 = 0.24	1.27 (p = 0.260)
	(4)	0.14	0.09	0.08	12 = 0.10	3 = 0.07
	(5)	0.07	0.06	0.06	7 = 0.06	3 = 0.07