Possible evidence for a common risk locus for bipolar affective disorder and schizophrenia on chromosome 4p16 in patients from the Faroe Islands

• Published in: Molecular psychiatry Vol. 9; no. 1; pp. 93 - 98
• Main Authors: ALS, T. D, DAHL, H. A, FLINT, T. J, WANG, A. G, VANG, M, MORS, O, KRUSE, T. A, EWALD, H
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing Group 01.01.2004
• Subjects: Adult and adolescent clinical studies; Biological and medical sciences; Bipolar disorder; Bipolar Disorder - ethnology; Bipolar Disorder - genetics; Bipolar disorders; Chromosomes; Chromosomes, Human, Pair 4; Demography; Denmark - epidemiology; Disease; Dopamine; Genes; Genetic Predisposition to Disease; Haplotypes; Humans; Medical sciences; Mood disorders; Pedigree; Population; Psychiatric research; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychoses; Risk Factors; Schizophrenia; Schizophrenia - ethnology; Schizophrenia - genetics; Atlantic Ocean Islands; Faroe Islands; Denmark; Aarhus Denmark; Psychosis; Mood disorder; Human; Schizophrenia; Bipolar disorder; Chromosome 4; Haplotype; Polymorphism
• ISSN: 1359-4184; 1476-5578
• DOI: 10.1038/sj.mp.4001393

Patients with schizophrenia (n=11) and bipolar affective disorder (n=17) from the relatively isolated population of the Faroe Islands were genotyped for 34 polymorphic markers on chromosome 4 in a search for allelic association and haplotype sharing among distantly related patients. When considering bipolar patients only, there was no clearcut support for any region on chromosome 4. The two-marker segment D4S394-D4S2983 at 4p16.1 was, however, supported by a P-value of 0.0162. For patients with schizophrenia, there was reasonable support for 4p16.1 as marker D4S2281 (P=0.0019), a two-marker segment (D4S2281-D4S1605, P=0.0009) and a three-marker segment (D4S2923-D4S2928-D4S1582, P-0.0005) appeared to be associated with schizophrenia, with some alleles/haplotypes occurring with different frequencies in patients compared to controls. When combining both psychiatric disorders, chromosome 4p16.1 received further support from five partially overlapping two- and three-marker segments (D4S394-D4S2983, P=0.0039; D4S2281-D4S1605, P=0.0027 and D4S394-D4S2983-D4S2923, P=0.006; D4S2923-D4S2928-D4S1582, P=0.00007; D4S1582-D4S1599-D4S2281, P=0.005). Increased haplotype sharing in patients with schizophrenia and in the combined data set was partly supported by Fisher's exact test and tests based on the genealogy. Our study yields support for a common risk gene for schizophrenia and bipolar affective disorder on the short arm of chromosome 4, as suggested by previous findings in the neighbouring Scottish population.