We conducted an association study assessing how PD risk in Italy was influenced by the serotonin transporter gene ( SLC6A4 ) polymorphic region 5-HTTLPR , consisting of an insertion/deletion ( long allele-L/short allele-S ) of 43 bp in the SLC6A4 promoter region .
O O O O O O O B-DiseaseOrPhenotypicFeature O O O O O O O B-GeneOrGeneProduct I-GeneOrGeneProduct O O B-GeneOrGeneProduct O O O B-GeneOrGeneProduct O O O O B-SequenceVariant I-SequenceVariant I-SequenceVariant I-SequenceVariant I-SequenceVariant I-SequenceVariant I-SequenceVariant I-SequenceVariant I-SequenceVariant O O B-GeneOrGeneProduct O O O