Chromosomal abnormalities and mental illness

• Published in: Molecular psychiatry Vol. 8; no. 3; pp. 275 - 287
• Main Authors: MACINTYRE, D. J, BLACKWOOD, D. H. R, PORTEOUS, D. J, PICKARD, B. S, MUIR, W. J
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing Group 01-03-2003
• Subjects: Adult and adolescent clinical studies; Biological and medical sciences; Bipolar disorder; Bipolar Disorder - genetics; Breakpoints; Chromosome Aberrations; Chromosomes; Cloning; Coexistence; Genes; Genetic analysis; Genetic Linkage; Genomes; Humans; Hypotheses; Intellectual disabilities; Intellectual Disability - genetics; Learning disabilities; Medical genetics; Medical sciences; Mental disorders; Miscellaneous; Mutation; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Schizophrenia; Schizophrenia - genetics; Sequence analysis; Susceptibility; United Kingdom > UK; Scotland; Mood disorder; Chromosomal aberration; Human; Linkage; Mental health; Schizophrenia; Chromosome; Exploration; Bipolar disorder; Developmental disorder; Mental retardation; Psychosis; Learning disability; Intellectual deficiency; Anomaly; Diagnosis
• ISSN: 1359-4184; 1476-5578
• DOI: 10.1038/sj.mp.4001232

Linkage studies of mental illness have provided suggestive evidence of susceptibility loci over many broad chromosomal regions. Pinpointing causative gene mutations by conventional linkage strategies alone is problematic. The breakpoints of chromosomal abnormalities occurring in patients with mental illness may be more direct pointers to the relevant gene locus. Publications that describe patients where chromosomal abnormalities co-exist with mental illness are reviewed along with supporting evidence that this may amount to an association. Chromosomal abnormalities are considered to be of possible significance if (a) the abnormality is rare and there are independent reports of its coexistence with psychiatric illness, or (b) there is colocalisation of the abnormality with a region of suggestive linkage findings, or (c) there is an apparent cosegregation of the abnormality with psychiatric illness within the individual's family. Breakpoints have been described within many of the loci suggested by linkage studies and these findings support the hypothesis that shared susceptibility factors for schizophrenia and bipolar disorder may exist. If these abnormalities directly disrupt coding regions, then combining molecular genetic breakpoint cloning with bioinformatic sequence analysis may be a method of rapidly identifying candidate genes. Full karyotyping of individuals with psychotic illness especially where this coexists with mild learning disability, dysmorphism or a strong family history of mental disorder is encouraged.