Evaluating the parent-of-origin effect in bipolar affective disorder. Is a more penetrant subtype transmitted paternally?
BACKGROUND
Numerous genetic mechanisms and modes of transmission underlying bipolar affective disorder (BPAD) have been postulated. Recently, the discovery of genomic imprinting and mitochondrial transmission of illness in humans has stimulated study of parent-of-origin effects in the transmission of BPAD.


METHODS
We examined a large sample of families from an associated linkage study to search for a possible parent-of-origin effect. Selecting for unilineal families with at least one offspring and/or parent diagnosed with BPAD after structured interview, we conducted three analyses: (1) the rates of illness among mothers and fathers of offspring affected with BPAD; (2) the observed frequency of transmission and rates of illness among maternal and paternal lineages; and (3) the rates of affective illness among offspring of parents affected with BPAD.


RESULTS
Our results indicate no significant differences in the rates of illness among mothers and fathers of offspring affected with BPAD. Also, the frequency of transmission and rates of illness among maternal and paternal lineages did not differ significantly. However, the rate of BPAD among the offspring of fathers affected with BPAD was significantly higher than for mothers with the illness.


CONCLUSIONS
Substantially more women than men, and maternal than paternal relatives were studied - introducing possible gender biases.


CONCLUSIONS
These results suggest a possible paternal parent-of-origin effect.
Kornberg
J R
JR
Departments of Psychiatry, Department of Veterans Affairs Medical Center and University of California, San Diego, CA 92093, USA.
Brown
J L
JL
Sadovnick
A D
AD
Remick
R A
RA
Keck
P E
PE
McElroy
S L
SL
Rapaport
M H
MH
Thompson
P M
PM
Kaul
J B
JB
Vrabel
C M
CM
Schommer
S C
SC
Wilson
T
T
Pizzuco
D
D
Jameson
S
S
Schibuk
L
L
Kelsoe
J R
JR
D001714:Bipolar Disorder / Q000175:diagnosis / Q000235:genetics*; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000235:genetics; D005220:Fathers; D005260:Female; D008040:Genetic Linkage / Q000235:genetics; D005820:Genetic Testing; D006801:Humans; D008297:Male; D009035:Mothers; D019683:Penetrance