title: Dermatoglyphics in relation to brain volumes in twins concordant and discordant for bipolar disorder.
abstract: Palmar and finger dermatoglyphics are formed between the 10th and the 17th weeks of gestation and their morphology can be influenced by genetic or environmental factors, interfering with normal intrauterine development. As both the skin and the brain develop from the same embryonal ectoderm, dermatoglyphic alterations may be informative for early abnormal neurodevelopmental processes in the brain. We investigated whether dermatoglyphic alterations are related to structural brain abnormalities in bipolar disorder and to what extent they are of a genetic and of an environmental origin. Dermatoglyphics and volumetric data from structural MRI were obtained in 53 twin pairs concordant or discordant for bipolar disorder and 51 healthy matched control twin pairs. Structural equation modeling was used. Bipolar disorder was significantly positively associated with palmar a-b ridge count (ABRC), indicating higher ABRC in bipolar patients (rph=.17 (CI .04-.30)). Common genes appear to be involved because the genetic correlation with ABRC was significant (rph-A=.21 (CI .05-.36). Irrespective of disease, ABRC showed a genetically mediated association with brain volume, indicated by a significant genetic correlation rph-A of respectively -.36 (CI -.52 to -.22) for total brain, -.34 (CI -.51 to -.16) total cortical volume, -.27 (CI -.43 to -.08) cortical gray matter and -.23 (CI -.41 to -.04) cortical white matter. In conclusion, a genetically determined abnormal development of the foetal ectoderm between the 10th and 15th week of gestation appears related to smaller brain volumes in (subjects at risk for) bipolar disorder.
authors.affiliation: Reinier van Arkel Groep, PO Box 70058, 5201 DZ, ׳s-Hertogenbosch, The Netherlands. Electronic address: r.vonk@RvAgroep.nl.
authors.forename: R
authors.initials: R
authors.lastname: Vonk
authors.affiliation: Alzheimer Nederland, Amersfoort, The Netherlands.
authors.forename: A C
authors.initials: AC
authors.lastname: van der Schot
authors.affiliation: Julius Centrum voor Gezondheidswetenschappen en Eerstelijns Geneeskunde, Afdeling, Biostatistiek, Utrecht, The Netherlands.
authors.forename: G C M
authors.initials: GC
authors.lastname: van Baal
authors.affiliation: Department of Real Estate & Housing, Faculty of Architecture, Delft University of Technology, Delft, The Netherlands.
authors.forename: C J
authors.initials: CJ
authors.lastname: van Oel
authors.affiliation: University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: W A
authors.initials: WA
authors.lastname: Nolen
authors.affiliation: Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center, Utrecht, Utrecht, The Netherlands.
authors.forename: R S
authors.initials: RS
authors.lastname: Kahn
mesh_terms: D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000235:genetics* / Q000473:pathology* / Q000523:psychology; D001921:Brain / Q000473:pathology*; D016022:Case-Control Studies; D003878:Dermatoglyphics; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging; D009929:Organ Size; D014429:Twins, Dizygotic / Q000235:genetics* / Q000523:psychology; D014430:Twins, Monozygotic / Q000235:genetics* / Q000523:psychology; D055815:Young Adult
keywords: Bipolar disorder; Dermatoglyphics; Genetics; Neurodevelopment; Twins