<p><b>Introduction</b>: Several studies suggested a possible association between certain polymorphisms in the <i>N-acetyl-transferase 2</i> (<i>NAT2</i>) gene (which encodes a very important enzyme involved in xenobiotic metabolism) and the risk for Parkinson’s disease (PD). As the results of studies on this issue are controversial, we conducted a systematic review and a meta-analysis of eligible studies on this putative association.</p> <p><b>Areas covered</b>: The authors revised the relationship between <i>NAT2</i> polymorphisms and the risk of developing PD using several databases, and performed a meta-analysis using the software <i>Meta-Disc1.1.1</i>. In addition heterogeneity between studies was analyzed. A description of studies regarding gene-gene interactions and gene-environmental interactions involving <i>NAT2</i> polymorphisms is also made.</p> <p><b>Expert opinion</b>: Despite several recent meta-analyses showing an association between several polymorphisms in genes related with detoxification mechanisms such <i>as cytochrome</i> P4502D6 (<i>CYP2D6</i>), and <i>glutathione transferases M1</i> and <i>T1</i> (<i>GSTM1</i>, and <i>GSTT1</i>), data on <i>NAT2</i> gene polymorphisms obtained from the current meta-analysis do not support a major association with PD risk, except in Asian populations. However, data from many studies are incomplete and therefore insufficient data exists to draw definitive conclusions. Several studies suggesting gene-gene and gene-environmental factors involving <i>NAT2</i> gene in PD risk await confirmation.</p
