Parkin Deletion And Meis1 P. R272H Mutation Analysis Of A Restless Legs Syndrome/Parkinson's Disease Pedigree

Objective:Restless Legs Syndrome (RLS) also known as Ekbom syndrome, is a clinical common sensorimotor nervous system disorder that is characterizedby an irresistible urge to move the legs, accompanied by abnormal sensations. These symptoms occur primarily at night during and relieved by movement. More than 50% of RLS patients have a positive family history. At present, Six positive linkage regions for RLS have been reported and formally classified as loci RLS1-6. Genome-wide association (GWA) studies have found four gene polymorphism associated with RLS, respectively BTBD9, Meisl, MAP2K5, LBXCOR1. The world first RLS related mutation Meisl p. R272H was reported by French C. Vilario-Guell by direct sequencing in 2009. The relation between RLS and Parkinson's disease (Parkinson Disease, PD) in the pathophysiology has been known for a long time, but whether there is intrinsic link between the two diseases in genetics? A RLS pedigree with 17 patients, spanning three-generation was reported by Susanna Adel in 2005, including two patients who were diagnosed as suspected Parkinson' s disease, and two others showed an isolated postural tremor. Exon7 or exon9 deletion of parkin gene was found in 8 of 17 RLS patients, which suggests that parkin deletion is not a disease-causative gene for RLS. But, the possibility that Parkin deletion is a risk factor for familial restless leg syndrome. In April 2009 we collected a RLS pedigree with 5 patients, spanning two-generation. In the second-generation, two patients also showed Parkinson's disease symptoms after their onset of restless leg syndrome and their father showed postural tremor. Because the pedigree we collected is similar with Susanna Adel's in a few clinical features, that is, they are both a primary RLS pedigree with several patients simultaneously suffering from Parkinson's disease. Therefore, we analized whether our RLS/PD family also has parkin deletion. We also detected the existence of Meis1 p. R272H mutation in this RLS pedigree.Materials and methods:The pedigree was collected from the neurological outpatient unit of the Qilu Hospital of Shandong University. Diagnosis of RLS was established according to the diagnostic criteria of the International Restless Legs Syndrome Study Group (IRLSSG).ALL the blood samples of the 12 members of the pedigree were collected by follow-up. The Parkin primers used see Hao Dengs research. Meis1 gene primer provided by C. Vilario-Guell. Genomic DNA was extracted with Phenol/chloroform procedure and polymerase chain reaction (PCR) amplification was performed to amplify 6 exon of Parkin gene and 1 exon of Meis1. DNA fragments were analyzed by the agrode gel electrophoresis. All the aimed fragments were purified and anayzed by direct gene sequencing.Results:1. Of all the 12 Exons of Parkin gene of proband and 119 of the pedgree were sequenced, we did not find any mutations except for a SNP in Exon42. There were not any Meis1 exon9 mutations found by sequencing.Conclusion:1. It is clear that Parkin exon mutations are not a disease-causative gene fragment for this RLS/PD pedigree, but the possibility that Parkin exon mutations is a risk factor for RLS/PD pedigree still exist. Therefore, we need detect Parkin mutationsl of all the RLS/PD patients in our family in the future. 2. The sense of the sNP (rs1801474) we discovered is still uncertain, it needs more evidence.