BACKGROUND: Medically unexplained chronic fatigue in childhood may cause considerable disability and (by definition) its cause remains unclear. A study of fatigue in healthy twins has been undertaken to examine whether or not genetic factors play a part. METHOD: A questionnaire survey of the main carers of an epidemiological population-based sample of 670 twin pairs who were asked about periods of unexplained and disabling fatigue in their twins. Out of 1340 individuals a period of disabling fatigue was reported for 92 (6.9%). Thirty-three (2.5%) reported disabling fatigue for more than 1 month. Zygosity could be confidently assigned in 98% of the sample providing 278 monozygotic (MZ) and 378 dizygotic (DZ) pairs. These data were analysed using a structural equation modelling approach. RESULTS: The results showed that disabling fatigue in childhood is highly familial with an MZ tetrachoric correlation (rMZ) of 0.81 and a DZ tetrachoric correlation (rDZ) of 0.59, for fatigue lasting at least a week. The most acceptable model using Akaike's information criteria, was one containing additive genetic effects (A) and shared environment (C) plus residual (or non-shared) environment (E). For fatigue lasting at least a month rMZ was 0.75 and rDZ 0.47. The most acceptable model included just A and E. However, the role of shared environment could not be conclusively rejected. CONCLUSIONS: Unexplained disabling fatigue in childhood is substantially familial. Both genetic and shared environmental factors are worth further exploration in a search for the causes.
BACKGROUND: Medically unexplained chronic fatigue in childhood may cause considerable disability and (by definition) its cause remains unclear. A study of fatigue in healthy twins has been undertaken to examine whether or not genetic factors play a part. METHOD: A questionnaire survey of the main carers of an epidemiological population-based sample of 670 twin pairs who were asked about periods of unexplained and disabling fatigue in their twins. Out of 1340 individuals a period of disabling fatigue was reported for 92 (6.9%). Thirty-three (2.5%) reported disabling fatigue for more than 1 month. Zygosity could be confidently assigned in 98% of the sample providing 278 monozygotic (MZ) and 378 dizygotic (DZ) pairs. These data were analysed using a structural equation modelling approach. RESULTS: The results showed that disabling fatigue in childhood is highly familial with an MZ tetrachoric correlation (rMZ) of 0.81 and a DZ tetrachoric correlation (rDZ) of 0.59, for fatigue lasting at least a week. The most acceptable model using Akaike's information criteria, was one containing additive genetic effects (A) and shared environment (C) plus residual (or non-shared) environment (E). For fatigue lasting at least a month rMZ was 0.75 and rDZ 0.47. The most acceptable model included just A and E. However, the role of shared environment could not be conclusively rejected. CONCLUSIONS: Unexplained disabling fatigue in childhood is substantially familial. Both genetic and shared environmental factors are worth further exploration in a search for the causes.
Authors: Richard J Williamson; Shaun Purcell; Abram Sterne; Simon Wessely; Matthew Hotopf; Anne Farmer; Pak C Sham Journal: Soc Psychiatry Psychiatr Epidemiol Date: 2005-02 Impact factor: 4.328
Authors: Karin Tritt; Marius Nickel; Ferdinand Mitterlehner; Cerstin Nickel; Petra Forthuber; Peter Leiberich; Wolfhardt Rother; Thomas Loew Journal: Wien Klin Wochenschr Date: 2004-03-31 Impact factor: 1.704
Authors: Harriet A Ball; Sisira H Siribaddana; Athula Sumathipala; Yulia Kovas; Nick Glozier; Peter McGuffin; Matthew Hotopf Journal: BMC Psychiatry Date: 2010-02-02 Impact factor: 3.630