Familial occurrence of microscopic colitis: a report on five families.
BACKGROUND
The etiology and pathogenesis of microscopic colitis is unknown. Whether genetic predisposition is of importance, as in many other gastrointestinal diseases, is unknown. Familial occurrence of collagenous colitis has earlier been reported only in two families.


METHODS
Familial occurrence of microscopic colitis was searched for in a Swedish national microscopic colitis register.


RESULTS
Familial occurrence of microscopic colitis was identified in five families. In all families a sister-sister relationship was found. Two sisters with collagenous colitis had been living apart in different Nordic countries for many years before developing the disease. In one pair, the smoking sister had collagenous colitis and the never smoking sister had lymphocytic colitis.


CONCLUSIONS
Considering the relative rarity of microscopic colitis, these findings indicate that a genetic predisposition may be of importance.
Järnerot
G
G
Dept. of Medicine, Orebro Medical Centre Hospital, Sweden.
Hertervig
E
E
Grännö
C
C
Thorhallsson
E
E
Eriksson
S
S
Tysk
C
C
Hansson
I
I
Björknäs
H
H
Bohr
J
J
Olesen
M
M
Willén
R
R
Kagevi
I
I
Danielsson
A
A
D000328:Adult; D000368:Aged; D003092:Colitis / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D012042:Registries / Q000706:statistics & numerical data; D012907:Smoking / Q000453:epidemiology; D013548:Sweden