Category Archives: genomics

On The Genetic Basis of Schizophrenia

“… what a narrow ridge of normality we all inhabit, with the abysses of mania and depression yawning to either side.”1

from reference 2

Schizophrenia is a debilitating condition, chronic in nature, that affects approximately 1 in a hundred people worldwide. Although able to strongly suggest a genetic basis, past research has not been truly successful in determining the hereditary underpinnings of this combined neurological and psychiatric disorder.

from reference 3

Two papers, published in the journal Nature, have pushed this field of research farther than ever before, establishing schizophrenia-relevant chromosomal loci and using larger numbers of patients than in the past, for stronger statistical power2,3. These studies focused on two types of chromosomal abnormalities, single nucleotide polymorphisms (SNPs; changes to single bases) and copy-number variations (CNVs; changes in the number of copies of one or more whole genes). Both studies confirmed previous findings of a CNV locus associated with schizophrenia, and validated each other’s implication of two new CNV loci. Although it is still unclear how such information might be used, this is a cause for enthusiasm regarding the treatment of schizophrenia, and the possibility of determining genetic basis for other psychiatric disorders.

1. Sacks, O. A Summer of Madness. The New York Review of Books, LV(14): 57-61, 2008.

2. Stefansson H, Rujescu D, Cichon S, Pietiläinen OP, Ingason A, Steinberg S, Fossdal R, Sigurdsson E, Sigmundsson T, Buizer-Voskamp JE, Hansen T, Jakobsen KD, Muglia P, Francks C, Matthews PM, Gylfason A, Halldorsson BV, Gudbjartsson D, Thorgeirsson TE, Sigurdsson A, Jonasdottir A, Jonasdottir A, Bjornsson A, Mattiasdottir S, Blondal T, Haraldsson M, Magnusdottir BB, Giegling I, Möller HJ, Hartmann A, Shianna KV, Ge D, Need AC, Crombie C, Fraser G, Walker N, Lonnqvist J, Suvisaari J, Tuulio-Henriksson A, Paunio T, Toulopoulou T, Bramon E, Di Forti M, Murray R, Ruggeri M, Vassos E, Tosato S, Walshe M, Li T, Vasilescu C, Mühleisen TW, Wang AG, Ullum H, Djurovic S, Melle I, Olesen J, Kiemeney LA, Franke B, Sabatti C, Freimer NB, Gulcher JR, Thorsteinsdottir U, Kong A, Andreassen OA, Ophoff RA, Georgi A, Rietschel M, Werge T, Petursson H, Goldstein DB, Nöthen MM, Peltonen L, Collier DA, St Clair D, Stefansson K, Kahn RS, Linszen DH, van Os J, Wiersma D, Bruggeman R, Cahn W, de Haan L, Krabbendam L, Myin-Germeys I; Genetic Risk and Outcome in Psychosis (GROUP). Large recurrent microdeletions associated with schizophrenia. Nature, 455(7210):232-236, 2008.

3. Stone JL, O’Donovan MC, Gurling H, Kirov GK, Blackwood DH, Corvin A, Craddock NJ, Gill M, Hultman CM, Lichtenstein P, McQuillin A, Pato CN, Ruderfer DM, Owen MJ, St Clair D, Sullivan PF, Sklar P, Purcell SM, Stone JL, Ruderfer DM, Korn J, Kirov GK, Macgregor S, McQuillin A, Morris DW, O’Dushlaine CT, Daly MJ, Visscher PM, Holmans PA, O’Donovan MC, Sullivan PF, Sklar P, Purcell SM, Gurling H, Corvin A, Blackwood DH, Craddock NJ, Gill M, Hultman CM, Kirov GK, Lichtenstein P, McQuillin A, O’Donovan MC, Owen MJ, Pato CN, Purcell SM, Scolnick EM, St Clair D, Stone JL, Sullivan PF, Sklar P, O’Donovan MC, Kirov GK, Craddock NJ, Holmans PA, Williams NM, Georgieva L, Nikolov I, Norton N, Williams H, Toncheva D, Milanova V, Owen MJ, Hultman CM, Lichtenstein P, Thelander EF, Sullivan P, Morris DW, O’Dushlaine CT, Kenny E, Waddington JL, Gill M, Corvin A, McQuillin A, Choudhury K, Datta S, Pimm J, Thirumalai S, Puri V, Krasucki R, Lawrence J, Quested D, Bass N, Curtis D, Gurling H, Crombie C, Fraser G, Kwan SL, Walker N, St Clair D, Blackwood DH, Muir WJ, McGhee KA, Pickard B, Malloy P, Maclean AW, Van Beck M, Visscher PM, Macgregor S, Pato MT, Medeiros H, Middleton F, Carvalho C, Morley C, Fanous A, Conti D, Knowles JA, Ferreira CP, Macedo A, Azevedo MH, Pato CN, Stone JL, Ruderfer DM, Korn J, McCarroll SA, Daly M, Purcell SM, Sklar P, Purcell SM, Stone JL, Chambert K, Ruderfer DM, Korn J, McCarroll SA, Gates C, Daly MJ, Scolnick EM, Sklar P. Rare chromosomal deletions and duplications increase risk of schizophrenia. Nature, 455(7210):237-241, 2008