Heritability of age of onset of psychosis in schizophrenia.
Schizophrenia is a genetically complex illness with heterogeneous clinical presentation, including variable age of onset. In this study, the heritability, or proportion of variation in age of onset of psychotic symptoms due to genetic factors, was estimated using a maximum likelihood method. The subjects were 717 members of families with more than one member affected with schizophrenia from Mexican and Central American populations. Age of onset of psychosis was determined by best-estimate consensus diagnosis based on the Diagnostic Interview for Genetic Studies, Family Interview for Genetic Studies, and each subject's medical records. Mean age of onset was 21.44 years (SD 8.07); 20.55 years for males (SD 6.90), and 22.67 for females (SD 9.34). Variance components were estimated using a polygenic model in the SOLAR software package. The sex of the participant was a significant covariate (P = 0.010) accounting for 0.02 of the total variance in age of onset. The heritability of age of onset of psychosis was 0.33 (SE = 0.09; P = 0.00004). These findings suggest that genetic factors significantly contribute to the age of onset of psychotic symptoms in individuals with schizophrenia and that sex influences this trait as well.
Hare
Elizabeth
E
South Texas Psychiatric Genetics Research Center, UT Health Science Center, San Antonio, San Antonio, Texas, USA. hare@uthscsa.edu
Glahn
David C
DC
Dassori
Albana
A
Raventos
Henriette
H
Nicolini
Humberto
H
Ontiveros
Alfonso
A
Medina
Rolando
R
Mendoza
Rick
R
Jerez
Alvaro
A
Muñoz
Rodrigo
R
Almasy
Laura
L
Escamilla
Michael A
MA
D000328:Adult; D017668:Age of Onset; D005260:Female; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide; D011618:Psychotic Disorders / Q000209:etiology* / Q000235:genetics; D012565:Schizophrenic Psychology