Limited information is available on the prevalence of gallstones in th
e first-degree relatives of gallstone patients. Three groups of subjec
ts were studied by realtime ultrasound examination: group A, 105 index
gallstone patients (male/female; 20:85); group B, 330 first-degree re
latives of index patients; group C, matched controls for group A (n =
105) and group B (n = 330) subjects. Dietary, anthropometric, and bioc
hemical investigations were carried out, In 39 of 105 (37%) index case
s, one or more additional family members had gallstones (positive-inde
x case). The positive-index cases were younger than the remaining inde
x cases (mean age, 33.1 +/- 14 vs. 44.5 +/- 13.1 years; P < .05). Fift
y-one of 330 (15.5%) first degree relatives had gallstones, nearly fou
r and a half times (95% confidence interval [CT], 2.4 to 8.5) more oft
en than in the matched control population (12 of 330 [3.6%]). Thirty-t
hree of 51 (65%) positive relatives were women; mother (37.3%), sister
(17.6%) or daughters (10%) to the index patients. There was no differ
ence in the diet, physical activity, and serum lipid pro file between
the positive index patients and the remaining gallstone patients and p
ositive relatives and their controls. Our results show that there is a
strong familial predisposition for gallstone formation. Female relati
ves of young gallstone patients should be routinely screened for galls
tones.