Linkage analysis of alcohol dependence symptoms in the community.
BACKGROUND
We have previously identified suggestive linkage for alcohol consumption in a community-based sample of Australian adults. In this companion paper, we explore the strength of genetic linkage signals for alcohol dependence symptoms.


METHODS
An alcohol dependence symptom score, based on DSM-IIIR and DSM-IV criteria, was examined. Twins and their nontwin siblings (1,654 males, 2,518 females), aged 21 to 81 years, were interviewed, with 803 individuals interviewed on 2 occasions, approximately 10 years apart. Linkage analyses were conducted on datasets compiled to maximize data collected at either the younger or the older age. In addition, linkage was compared between full samples and truncated samples that excluded the lightest drinkers (approximately 10% of the sample).


RESULTS
Suggestive peaks on chromosome 5p (LODs >2.2) were found in a region previously identified in alcohol linkage studies using clinical populations. Linkage signal strength was found to vary between full and truncated samples and when samples differed only on the collection age for a sample subset.


CONCLUSIONS
The results support the finding that large community samples can be informative in the study of alcohol-related traits.
Genetic Epidemiology, Queensland Institute of Medical Research, Brisbane, Australia. Narelle.Hansell@qimr.edu.au
Narelle K
NK
Hansell
Arpana
A
Agrawal
John B
JB
Whitfield
Katherine I
KI
Morley
Scott D
SD
Gordon
Penelope A
PA
Lind
Michele L
ML
Pergadia
Grant W
GW
Montgomery
Pamela A F
PA
Madden
Richard D
RD
Todd
Andrew C
AC
Heath
Nicholas G
NG
Martin
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000453:epidemiology / Q000235:genetics*; D000437:Alcoholism / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D008040:Genetic Linkage / Q000235:genetics*; D006801:Humans; D008126:Lod Score; D008297:Male; D008875:Middle Aged; D012111:Residence Characteristics; D055815:Young Adult