Table 2. Estimates of familial correlations ± standard error for serum haptoglobin concentration (656 familles/2680 individuals).

	Model 1	Model 2	Model 3	Model 4
Adjustment for	None	Age & BMI	Age & BMI	Age, BMI & rs2000999 allelic frequency
Father - Mother (FM)	0.126±0.038	0.111±0.038**	0.111±0.038**	0.156±0.038***
Father - Son (FS)	0.277±0.037	0.264±0.037***	0.230±0.021***	0.206±0.022***
Father - Daughter (FD)	0.277±0.036	0.265±0.037***	[0.230]	[0.206]
Mother - Son (MS)	0.227±0.036	0.204±0.037***	[0.230]	[0.206]
Mother - Daughter (MD)	0.184±0.039	0.188±0.040***	[0.230]	[0.206]
Son - Son (SS)	0.213±0.060	0.186±0.064**	0.274±0.036***	0.239±0.036***
Son - Daughter (SD)	0.273±0.047	0.271±0.047***	[0.274]	[0.239]
Daughter - Daughter (DD)	0.355±0.067	0.386±0.064***	[0.274]	[0.239]
Loge L2 (Logarithm of likelihood function)	1458.83	1338.20	1342.20	1215.13
Alternate model		Model 1	Model 2	Model 3
χ2 (df)		241.26(8)	8.00(5)	254.14(4)
P		***	NS	***

* P≤0.05, ** P≤0.01, *** P≤0.001: compared to zero.

Model 1 estimated all eight correlations without adjustment.

Model 2 estimated all eight correlations with adjustment for age and BMI,

Model 3 estimated three correlations with adjustment for age and BMI with no gender effect on parent or offspring correlations: FS = MS = MD = FD and SS = SD = DD.

Model 4 estimated three correlations with adjustment for age, BMI and rs2000999 allelic frequency with no gender effect on parent or offspring correlations: FS = MS = MD = FD and SS = SD = DD.

Values in brackets were constrained to be equal to a preceding value according to the hypotheses of the model.

BMI: body mass index.