Epidemiology,Imaging And Gene Mutation Of Basal Ganglia Calcification

Background & Objective: With the extensive application of CT and MRI,Calcification of basal ganglia has become a common sign in clinical neuroimaging.It has beenreported that basal ganglia calcification(BGC)is common in the normal population,And had a positive correlation with age.The study found that a variety of factorscan cause basal ganglia calcification,including hypoparathyroidism,microbial infection,age,cancer and a variety of physical and chemical factors.Among them,normal aging caused by calcification and idiopathic basal ganglia calcification(IBGC)in clinical difficult to distinguish.At the same time,at present,the calcification of calcification of basal ganglia is more chaotic,there is no uniform assessment of calcication standards,affecting the basal ganglia calcification of academic exchanges,but also no standardized BGC epidemiological survey data.And idiopathic basal ganglia calcification(IBGC)as a special type of BGC,its genotype and clinical phenotype relationship is not clear.Therefore,our aim is: 1,trying to establish a unified calcificationscoring system to explore the BGC in the general population in the proportion of calcification and its gender,age,2,further study of IBGC patients with clinical phenotype and genotype and Its relationship with age,gender,3,in a large group of southernChina IBGC patients screening gene mutation,to understand its gene mutation in theChinese population spectrum.Methods: First,a new visual calcification scoring system was established with reference to the French rating scale of Nicolas G,and the evaluation was conducted from January 1,2015 to December 31,2015 in our hospital,emergency and Hospitalized basal ganglia calcification(BGC)of all unselected patients with head CT.According to the age of patients divided into five groups: 20 years of age group,21-40 years old group,41-60 years group,61-80 years group,81 years old group.According to the sex of the patients: male group,female group.The calcification ratio and visual calcification score of each age group and male and female were counted.According to the IBGC diagnostic criteria proposed by Manyam et al.in 2005,35 patients with IBGC were screened from the above patients,including 12 IBGC family probands and 23 sporadic cases.Clinical data were collected using visual calcification scoring system and CT gene was used to evaluate the calcification of CT in the head.All the exon and adjacent intron regions of SLC20A2,PDGFRB and PDGFB,XPR1 genes in IBGC cases were detected by PCR and Sanger sequencing.The IBGC control group was compared to the gene of the control group to identify the gene mutation sites of IBGC.Results: 1.retrospective collection of unselected head CT patients in a total of 15627 people,according to visual calcification scoring system,a total of 1234 cases of BGC cases were found,the total calcification ratio of 7.90%.Among them,8428 were unselected male cases,433 were found in BGC cases and 5.14% in calcification cases.Of the unselected female cases,7199 were found,800 cases of BGC were found,and the calcification ratio was 11.11%.The proportion of calcification in women was higher than that in men,which was statistically significant.The calcification ratio of male and female was positively correlated with age(P <0.05).BGC visual calcification score is generally low,mainly L1.1 and L2.2.2.Cases of 65 IBGC cases were collected,the proportion of men and women was 32:33,there was no significant difference.No clinical symptoms and symptomatic patients were 51:14(78.46%: 21.54%),no clinical symptoms accounted for a high proportion.Clinical symptoms include: dizziness 6(33.3%),headache 6(33.3%),memory loss of 4(22.2%),Parkinson's symptoms 1(7.1%).The calcification score and CT value of the same location in different cases were not necessarily positively correlated.Visual calcification score and BGC,IBGC patients were positively correlated with age.3.In the 35 cases of IBGC,eight mutations were found in the mutant families and sporadic cases,including SLC20A2 gene mutations(2 families,3 sporadic cases),PDGFRB gene mutations(1 pedigree,1 sporadic case),PDGFB gene Mutation(1 sporadic case).Four new mutations of SLC20A2 gene and one new PDGFRB gene were found.Patients with SLC20A2 mutations have higher calcification scores and higher CT values than patients with PDGFRB mutations,especially in the lentiform nucleus.Conclusion: 1.In our cross-sectional survey,we found that the proportion of BGC calcification in the normal population was higher than that in men,and the proportion of male and female calcification increased with age,but the proportion of male and female calcification in IBGC patients in southern China was Significant differences.In IBGC patients,no clinical symptoms accounted for a large proportion.2.At present,the classification criteria of calcification have not yet been unified,and the establishment of new calcification scoring system is very important for the study of the relationship between genotype and clinical phenotype,combined with CT value can be more three-dimensional reaction calcification.The visual calcification score of IBGC increased with age.3.In the IBGC gene mutation screening,there are a large number of cases of undetermined genetic patterns,suggesting that we have other IBGC pathogenic genes were not found.The visual calcification score between SLC20A2 gene and PDGFRB gene mutation is different,suggesting that the visual calcification scoring system is feasible for evaluating clinical phenotype-genotype relationships but still needs to be validated among other genotypes.