X inactivation as a source of behavioural differences in monozygotic female twins - PubMed (original) (raw)

Comparative Study

X inactivation as a source of behavioural differences in monozygotic female twins

Caroline S Loat et al. Twin Res. 2004 Feb.

Free article

Abstract

Although members of monozygotic twin pairs are identical in genome sequence, they may differ in patterns of gene expression. One early and irreversible process affecting gene expression, which can create differences within pairs of female monozygotic twins, is X inactivation - one twin can express mainly paternally-received genes on the X chromosome while the other twin expresses mainly maternally-received genes. It follows that non-identical X chromosome expression may cause female monozygotic twins to correlate less strongly than male monozygotic twins on complex behavioural traits affected by X-linked loci. We tested this hypothesis using data from around 4000 same-sex twin pairs on 9 social, behavioural and cognitive measures at ages 2, 3 and 4. Consistent with our hypothesis, monozygotic males were generally more similar than monozygotic females. Three of four significant differences were in traits showing higher correlations in males than females, and these traits - prosocial behaviour, peer problems, and verbal ability - have all been proposed previously in the literature as being influenced by genes on the X chromosome. Interestingly, dizygotic twins showed the reverse pattern of correlations for similar variables, which is also consistent with the X inactivation hypothesis; taken together, then, our monozygotic and dizygotic results suggest the presence of quantitative trait loci on the X chromosome.

PubMed Disclaimer

Similar articles

• X-inactivation patterns in monozygotic and dizygotic female twins.
  Goodship J, Carter J, Burn J. Goodship J, et al. Am J Med Genet. 1996 Jan 22;61(3):205-8. doi: 10.1002/(SICI)1096-8628(19960122)61:3<205::AID-AJMG3>3.0.CO;2-T. Am J Med Genet. 1996. PMID: 8741864
• X chromosome inactivation patterns correlate with fetal-placental anatomy in monozygotic twin pairs: implications for immune relatedness and concordance for autoimmunity.
  Trejo V, Derom C, Vlietinck R, Ollier W, Silman A, Ebers G, Derom R, Gregersen PK. Trejo V, et al. Mol Med. 1994 Nov;1(1):62-70. Mol Med. 1994. PMID: 8790602 Free PMC article.
• X-chromosome inactivation is mostly random in placental tissues of female monozygotic twins and triplets.
  Bamforth F, Machin G, Innes M. Bamforth F, et al. Am J Med Genet. 1996 Jan 22;61(3):209-15. doi: 10.1002/(SICI)1096-8628(19960122)61:3<209::AID-AJMG4>3.0.CO;2-P. Am J Med Genet. 1996. PMID: 8741865
• The mechanism of emergenesis.
  Lykken DT. Lykken DT. Genes Brain Behav. 2006 Jun;5(4):306-10. doi: 10.1111/j.1601-183X.2006.00233.x. Genes Brain Behav. 2006. PMID: 16716200 Review.
• Non-identical monozygotic twins, intermediate twin types, zygosity testing, and the non-random nature of monozygotic twinning: a review.
  Machin G. Machin G. Am J Med Genet C Semin Med Genet. 2009 May 15;151C(2):110-27. doi: 10.1002/ajmg.c.30212. Am J Med Genet C Semin Med Genet. 2009. PMID: 19363805 Review.

Cited by

• The insectan apes.
  Crespi B. Crespi B. Hum Nat. 2014 Mar;25(1):6-27. doi: 10.1007/s12110-013-9185-9. Hum Nat. 2014. PMID: 24307448
• ASD in females: are we overstating the gender difference in diagnosis?
  Kreiser NL, White SW. Kreiser NL, et al. Clin Child Fam Psychol Rev. 2014 Mar;17(1):67-84. doi: 10.1007/s10567-013-0148-9. Clin Child Fam Psychol Rev. 2014. PMID: 23836119
• Genes that escape from X inactivation.
  Berletch JB, Yang F, Xu J, Carrel L, Disteche CM. Berletch JB, et al. Hum Genet. 2011 Aug;130(2):237-45. doi: 10.1007/s00439-011-1011-z. Epub 2011 May 26. Hum Genet. 2011. PMID: 21614513 Free PMC article. Review.
• Methyl-CpG-binding protein 2 polymorphisms and vulnerability to autism.
  Loat CS, Curran S, Lewis CM, Duvall J, Geschwind D, Bolton P, Craig IW. Loat CS, et al. Genes Brain Behav. 2008 Oct;7(7):754-60. doi: 10.1111/j.1601-183X.2008.00414.x. Genes Brain Behav. 2008. PMID: 19125863 Free PMC article.
• X-chromosome inactivation patterns in monozygotic twins and sib pairs discordant for nonsyndromic cleft lip and/or palate.
  Kimani JW, Shi M, Daack-Hirsch S, Christensen K, Moretti-Ferreira D, Marazita ML, Field LL, Canady JW, Murray JC. Kimani JW, et al. Am J Med Genet A. 2007 Dec 15;143A(24):3267-72. doi: 10.1002/ajmg.a.32098. Am J Med Genet A. 2007. PMID: 18000982 Free PMC article.

Publication types

MeSH terms

LinkOut - more resources

• Full Text Sources

  • CORE