Elsevier

Schizophrenia Research

Volume 21, Issue 3, 18 September 1996, Pages 151-160
Schizophrenia Research

Reproductive fitness in familial schizophrenia

https://doi.org/10.1016/0920-9964(96)00018-7Get rights and content

Abstract

Background: Reproductive fitness is an important factor in understanding inheritance in genetic disorders. The purpose of this study was to determine whether fitness is reduced in familial schizophrenia (FS) and if fitness in siblings differs from the norm. Method: The number of offspring in 36 subjects with RDC schizophrenia or schizoaffective disorder (SZ) and their 101 siblings from large FS families was compared with age-adjusted census figures. Results: Fitness in the SZ group was significantly reduced: 23% of expected in males and 51% of expected in females. Fitness of unaffected siblings was within census expectations. However, female siblings with schizophrenia spectrum features had increased fitness over census norms. Reduced fitness was correlated with low marital rates, poor functioning and positive symptoms. Conclusions: These results indicate that reduced fitness is an important genetic force in FS and is likely inherent to the illness. Sex differences are important and would need to be considered when examining maternal and paternal transmission of schizophrenia. The results support a proposed high mutation rate for schizophrenia, consistent with a dynamic mutation mechanism.

References (53)

  • C. Buck et al.

    Fertility of the sibs of schizophrenic patients

    Br. J. Psychiatry

    (1975)
  • N. Carey et al.

    Meiotic drive at the myotonic dystrophy locus?

    Nature Genet.

    (1994)
  • T.J. Crow

    Sexual selection, Machiavellian intelligence and the origins of psychosis

    Lancet

    (1993)
  • T.J. Crow

    A Darwinian approach to the origins of psychosis

    Br. J. Psychiatry

    (1995)
  • C.E.M. de Die-Smulders et al.

    Anticipation resulting in elimination of the myotonic dystrophy gene: a follow up study of one extended family

    J. Med. Genet.

    (1994)
  • L. Erlenmeyer-Kimling

    Fertility of psychotics

  • L. Erlenmeyer-Kimling et al.

    Selection and schizophrenia

    Am. Naturalist

    (1966)
  • L. Erlenmeyer-Kimling et al.

    Family formation by schizophrenics

  • E. Essen-Moller

    Mating and fertility patterns in families with schizophrenia

    Eugenics Q.

    (1959)
  • L. Fananas et al.

    Reproductive rates in families of schizophrenic patients in a case-control study

    Acta Psychiatr. Scand.

    (1995)
  • J. Flint

    Implications of genomic imprinting for psychiatric genetics (editorial)

    Psychol. Med.

    (1992)
  • J.-P. Fryns

    The female and the fragile X

    Am. J. Med. Genet.

    (1986)
  • I.I. Gottesman et al.

    Schizophrenia: The Epigenetic Puzzle

    (1982)
  • J.B.S. Haldane

    The rate of spontaneous mutation of a human gene

    J. Genet.

    (1935)
  • F. Haverkamp et al.

    Is there an increase of reproductive rates in schizophrenics? I. Critical review of the literature

    Arch. Psychiatry Neurol. Sci.

    (1982)
  • W.L. Hays

    Statistics

    (1988)
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