Table 2 Frequency of genotypes expressing low levels of mannan‐binding lectin (MBL) and C4AQ0 in five families after stratification for families with low MBL.

	Patients with SLE, n = 14 (%)	First‐degree relatives, n = 56 (%)	Second‐degree relatives, n = 16 (%)	p*	p*
Low MBL genotypes	64	38	0	<0.001	<0.001
C4AQ0	50	46	44	0.94	0.73
Low MBL with C4AQ0	36	18	0	0.036	0.011

MBL, mannan‐binding lectin; SLE, systemic lupus erythematosus.

*χ² test for independence between patients with SLE, first‐degree relatives and second‐degree relatives.

†χ² test for trend between patients with SLE , first‐degree relatives and second‐degree relatives.