Human Genetics

, Volume 122, Issue 3–4, pp 409–411 | Cite as

Comments on the paper by D. Li and L. He: Meta-analysis shows association between the tryptophan hydroxylase (TPH) gene and schizophrenia

  • P. G. SandEmail author
Letter to the Editors
In their recent paper, Li and He ( 2006) have provided what may be described as a “bulk meta-analysis” of genetic association data in schizophrenia, i.e. a set of three parallel meta-analyses involving multiple markers. Ideally, meta-analyses should improve the signal-to-noise ratio so that weak, yet robust effects may be appreciated more readily compared to consulting data from individual studies. This does not, however, eliminate confounders such as ethnic and diagnostic heterogeneity (Jablensky 2006). Intriguingly, Li and He have claimed an association between a TPH gene variant and schizophrenia using (a) pooled ethnicities, (b) pooled polymorphisms, and (c) pooled clinical entities. Their finding suggests the precautions proposed (Burchard et al. 2003) to ensure the homogeneity of samples prior to conducting meta-analyses are either unnecessary in general, or need not be applied to studies of schizophrenia. In other words, can we accelerate discovery by relaxing classification...


Schizophrenia Personality Disorder Major Depressive Disorder Schizoaffective Disorder Invalid Data 
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Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Department of PsychiatryUniversity of RegensburgRegensburgGermany

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