Fróðskaparrit - 31.12.2000, Side 53

LEITAN EFTIR ILEGUMØGULEIKUM A UTVALDUM KROMOSOMUM
HJA FØROYSKUM SJUKLINGUM Vlð SINNISLIGUM SJUKUM
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were interviewed by experienced psychia-
trists using a brief version of the Present
State Examination (Wing et al., 1990). On
the basis of the interview, a clinical narra-
tive was made for each patient. Final diag-
nosis was made by consensus as a best esti-
mate by a psychiatrist who independently
had reviewed the clinical narrative and if
necessary other relevant material.
The diagnoses were made in accordance
with the ICD-10 Diagnostic Criteria for Re-
search (WHO, 1996). Groups of ten to
twenty patients with each disorder, accord-
ing to ICD-10, were included in the study.
Twenty-five control families, unscreened
for psychiatric disorders, were collected
from the same sub-region of the Faroe Is-
lands.
Genealogical Assessment
Cases related six to ten generations ago
were sought in order to obtain a reasonable
size of shared chromosomal segment
around putative disease genes. A ge-
nealogical search of church and civic
records of births, marriages, and deaths was
made for each patient. Lineage was traced
back as far as possible in order to determine
if the patients were related. The shortest
possible distance between any pair of the
patients’ parents was established. Excel-
lent church records exist from around 1700,
while civic records exist from even earlier.
In our studies, all patients from each group
were related back to the middle of the 17th
century, five to eleven generations ago.
Statistical Analyses
For each microsatellite marker, allele and
segment frequencies were computed and
compared between the cases and controls.
Comparisons of haplotypes or alleles be-
tween cases and controls were tested by
chi-square analyses or Fisher’s exact test.
Statistical calculations were performed by
CLUMP (Sham, 1998). Generally, a sig-
nificant difference is obtained by a p-value
of 0.05 or less, indicating a probability of
0.05 or less for an arbitrary difference.
However, in genetics some authors argue
for more strict criteria, such as a p-value of
0.01 or less.
Results
In the ongoing genome screening, we do
see interesting regions, i.e. regions with in-
creased haplotype sharing among cases
when compared to controls.
Bipolar Ajfective Disorder
For bipolar affective disorder, we have re-
sults that support a previous reported fmd-
ing in two Costa Rican pedigrees (Freimer
etal., 1996). Several markers seemtopoint
to the area distally on 18q, possibly related
to bipolar disorder (Table 1). These results
have been published previously (Ewald et
al., 1997; Wang et al., 1998; Ewald et al.,
1999b; Nyegaard et ai, 1999). Recently, a
new, interesting area has been found on
chromosome 10q26 (Ewald et al., 1999a;
2000), Table 1.
Schizophrenia
Studies related to schizophrenia have been
described in posters at the World Congress
on Psychiatric Genetics in 1999 and 2000.
Studies on chromosome 22 could not con-