RT Journal Article SR Electronic T1 Segmental uniparental isodisomy on 5q32-qter in a patient with childhood-onset schizophrenia JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 887 OP 892 DO 10.1136/jmg.2006.043380 VO 43 IS 11 A1 J L Seal A1 M C Gornick A1 N Gogtay A1 P Shaw A1 D K Greenstein A1 M Coffey A1 P A Gochman A1 T Stromberg A1 Z Chen A1 B Merriman A1 S F Nelson A1 J Brooks A1 S Arepalli A1 F Wavrant-De Vrièze A1 J Hardy A1 J L Rapoport A1 A M Addington YR 2006 UL http://jmg.bmj.com/content/43/11/887.abstract AB Schizophrenia is a severe mental disorder affecting approximately 1% of the world’s population. Although the aetiology of schizophrenia is complex and multifactorial, with estimated heritabilities as high as 80%, genetic factors are the most compelling. Childhood-onset schizophrenia (COS), defined as onset of schizophrenia before the age of 13 years, is a rare and malignant form of the illness that may have more salient genetic influence. The first known case of paternal segmental uniparental isodisomy (iUPD) on 5q32-qter in a patient with COS is described, which adds to the previously known high rates of chromosomal abnormalities reported in this sample. iUPD is a rare genetic condition in which the offspring receives two chromosomal homologues from one parent. Segmental UPD is defined as UPD on a portion of a chromosome with biparental inheritance seen in the rest of the homologous pair. Complications owing to this abnormality may arise from malfunctioning imprinted genes or homozygosity of recessive disease-causing mutations. This aberration became apparent during whole-genomic screening of a COS cohort and is of particular interest because 5q has been implicated in schizophrenia by several genomewide linkage studies and positive gene associations. This report, therefore, presents more evidence that schizophrenia susceptibility gene, or genes, may be found on distal 5q.