Frequencies of polymorphisms in cytokines, neurotransmitters and adrenergic receptors in patients with complex regional pain syndrome type I after distal radial fracture.

OBJECTIVES: The complex regional pain syndrome type I (CRPS I) is one of the main complications after a fracture of the distal radius. The underlying pathology is not fully understood. Different theories have been put forward to explain the pathogenesis of this disease, some including genetic models. The aim of this study was to find a possible genetic involvement in the occurrence of CRPS I.

METHODS: We tested for known single nucleotide polymorphisms in cytokines, adrenergic receptors, and inflammatory neuropeptides in a cohort of patients at risk to develop CRPS I after a distal radius fracture. Subjective pain and functional parameters were recorded during the course of 1 year after trauma.

RESULTS: Fifteen of 163 patients with fractures of the distal radius were diagnosed with CRPS I according to the International Association for the Study of Pain research criteria. A significant association was detected for the rs1048101 polymorphism of the alpha1a-adrenoceptor. All other tested variants were not associated with CRPS I. Patients with CRPS I fared worse in all functional tests compared with the control group.

DISCUSSION: This study suggests the rs1048101 single nucleotide polymorphism within the alpha1a-adrenoceptor as one risk factor for the development of CRPS I after the distal radius fracture.