Following the recent identification of multiple novel mutations and alleles
of the cytochrome P450 CYP2D6 gene which cause decreased, increased, or ab
sent enzyme activity. we re-examined the controversial hypothesis of a role
of the CYP2D6 polymorphism in Parkinson's disease (PD) susceptibility. For
this purpose, a strategy based on PCR-SSCP and RFLP analyses allowing the
detection of all known CYP2D6 alleles was performed in DNA from 109 patient
s with sporadic PD. This strategy was also applied to DNA from 68 members o
f PD families including 18 affected and 50 unaffected members. Seventeen mu
tations occurring alone or in various combination on 14 alleles of CYP2D6 h
ave been identified in patients with sporadic PD. Moreover, 12 mutations an
d nine alleles of the gene have been characterized in members of PD familie
s. No significant difference was observed when the distribution of mutation
s and alleles of CYP2D6 was compared between the PD patients and 514 contro
l subjects previously analyzed using the same strategy. There was also no d
ifference in the distribution of phenotypes predicted from genotypes betwee
n both groups. In addition, when the distribution of CYP2D6 genotypes was c
ompared, no difference between affected and unaffected members of PD famili
es was observed. These data indicate that CYP2D6 polymorphism is not a susc
eptibility factor to PD.