Table 4.

MGUS among first-degree relatives of MGUS patients by sex of relative, type of relative, and age of probands at diagnosis

	First-degree relatives of MGUS patients (n = 14621)	First-degree relatives of controls (n = 58387)	RR (95% CI)*
Sex of relative
Male	13	15	3.5 (1.5-8.5)†
Female	9	16	2.2 (0.8-5.9)
Type of first-degree relative
Parent	9	13	2.7 (1.2-6.3)†
Sibling	6	5	4.9 (1.2-20)†
Offspring	7	13	2.2 (0.9-5.6)
Age at MGUS diagnosis for proband, y
Less than 65	15	18	3.2 (1.5-6.9)†
65 or older	7	13	2.2 (0.9-5.5)

^*All estimates were adjusted for sex of first-degree relative.

^†Statistically significant (2-sided P value < .05).