per OMIM, Ma et al. (2005) [PMID 15879433] found two different DDC haplotypes associated with nicotine dependence in African Americans and European Americans (with measures of smoking quantity [SQ], heaviness of smoking index [HSI], and the Fagerstrom test for ND [FTND])
- in African Americans, rs921451(T), rs3735273(G), rs1451371(T), rs2060762(G), all three measures sig. associated after correction for multiple testing
- in European Americans, rs921451(T), rs3735273(G), rs1451371(T), rs3757472(G), which showed a sig. assoc. w/ the SQ and FTND score
[PMID 19221445] Tyrosine hydroxylase and DOPA decarboxylase gene variants in personality traits
[PMID 17184203] DOPA decarboxylase gene is associated with nicotine dependence.
[PMID 17948905] Dopa decarboxylase and tyrosine hydroxylase gene variants in suicidal behavior.