Analysis Of Clinical Features And Gene Mutation Sites In 116 Patients With Wilson’s Disease

Background and Objectives:Wilson’s disease(WD)is an autosomal recessive genetic disorder with a global incidence of approximately 1:30,000 ‐ 1:100,000 due to gene mutation in the ATP7 B gene that causes copper deposition in the liver and other organs and organ damage.The purpose of this study is through the collection between December 2012 and August 2020 Jilin University First Hospital outpatient or hospitalization diagnosis for WD in patients with clinical data,including age,gender,first symptom,coagulation routine,liver function,copper biochemical,K-F ring and gene testing and other related results,the clinical characteristics and gene mutations were analyzed to explore the clinical characteristics of each clinical phenotype and the relationship between the clinical characteristics and gene mutations.Method:By obtaining the consent of the patients or their guardians and signing the informed consent,we collected the basic information,first symptom,blood routine,blood coagulation routine,liver function,serum copper,ceruloplasmin,24-hour urine copper,gene mutation sites and other data of 116 patients with WD.Serum samples from 31 patients were sent to the gene testing center for high-throughput gene sequencing to identify the mutation sites,and the ATP7 B gene database was searched to compare with the gene mutation sites that have been found so far in order to find new mutation sites.In this study,R 4.0.2 was applied to conduct statistical analysis on all the data,and the chi-square test was used to compare the differences among various indicators in typing.When P < 0.05 on both sides,the difference was considered to be statistically significant in this study,so as to clarify the clinical characteristics of each clinical phenotype.Results:1.We summarized and analyzed the basic information of 116 patients,and divided them into liver type(80,69.0%),brain type(18,15.5%)and mixed type(18,15.5%)according to the initial symptoms and clinical manifestations.The onset age of liver type patients was relatively early,34.6% of liver type patients were at7-14 years old,and the onset age of brain type and mixed type patients was mostly between 15 and 35 years old(accounting for 83.3% and 55.6% of each phenotype,respectively),the difference was statistically significant(P<0.001).2.The liver function indexes of the 116 patients were analyzed,and the aspartate aminotransferase(AST)and alanine transaminase(ALT)of the liver type patients were significantly increased,showing a two-way increasing trend,with the median and quartile intervals of 81.6(50.9,127.1)and 81(32.2,160.4),respectively,and the difference among all groups was statistically significant(P < 0.05).The level of alkaline phosphatase(ALP)in liver type patients was the highest among the three groups,which was 190.6 U/L(97.5 U/L,287.4 U/L).The ALP levels of brain type and mixed type patients were 89.3(71.2,160.2)and 79(63.6,104.3),respectively,and the difference among all groups was statistically significant(P < 0.01).3.Fibrinogen(FBG)levels were 1.89(1.35,2.29)in patients with liver type,2.15(1.67,2.43)in patients with brain type,and 1.63(1.08,1.98)in patients with mixed type.The differences between different clinical phenotypes and FBG levels were statistically significant(P < 0.05).4.The ceruloplasmin(CP)level in brain type patients was 0.02(0.02,0.02).The levels of CP in liver type and mixed type patients were 0.04(0.02,0.07)and 0.05(0.03,0.06)respectively.Moreover,there were statistical differences in CP levels between liver type and brain type,brain type and mixed type(P < 0.01).5.In this study,a total of 85 patients with WD underwent K-F ring detection,and the results showed that the positive rate of K-F ring was 45.2% in patients with liver type,100% in patients with brain type,and 66.7% in patients with mixed type.The difference of the positive rate of K-F ring among different clinical phenotypes was statistically significant(P < 0.01).6.Among the 12 patients with fulminant Wilson’s disease(FWD),8 patients were female(66.7%).Serum transaminase(AST)was mainly increased while ALP level was significantly decreased.ALP/ TBil < 2 in all patients,and AST/ ALT>4 in 4patients.The levels of 24 h urinary copper,serum copper and serum free copper increased significantly,and the higher the level of serum free copper,the worse the prognosis of patients.A total of 7 patients with FWD had a prognostic score of ≥11,and three patients with a score greater than 11 had an ALP lower than 40U/L,and liver transplantation was the best treatment option.7.A total of 21 gene mutation sites were detected in 31 patients with ATP7 B gene,which were c.3818C>T,c.2621C>T,c.1708-5T>G,c.2294A>G,c.3517G>A,c.2930C>T,c.2333G>T,c.2975C>T,c.3305T>C,c.2447+5G>T,c.2906G>A,c.3443T>C,c.1543+1G>T,c.3877G>A,c.3889G>A,c.3809A>G,c.3859G>A,c.4066-6C>T,c.3104G>T,c.2755C>G,c.3056A>C,respectively.All of them were heterozygous mutations,among which the compound heterozygous mutations accounted for 54.8%.Two hot spot mutations were found which were Arg778Leu(c.2333G>T)on Exon 8(29.1%)and A874V(c.2621C>T)on Exon 11(19.4%).c.2294A>T gene mutation site on Exon 8 tends to occur in patients with liver type.A new mutation site was found,namely c.1708-5T>G,which was located on Intron 4.8.Among the 21 gene mutation sites,mainly including missense mutation 17(81%),one splicing mutation(4.8%),three kinds of clinical significance is unknown mutations(14.3%),all mutations are heterozygous mutations,17 patients were detected 2 and above gene mutation sites,namely compound mutation,accounted for54.8% of the total,the rest of 14 patients with only one gene mutation sites,which was 45.2% of the total population.The gene mutation sites in 8 patients with FWD aged ≤14 years were heterozygous,and the compound heterozygous mutation was dominant(60%).Two patients,both aged 14 years,developed c.3517G>A on Exon16.Conclusions:1.There were differences in age,AST,ALT,K-F ring,CP and FBG among WD patients with different clinical phenotypes.2.Two hot spot mutation sites were found in Jilin region,which were Arg778Leu(c.2333G>T)on Exon 8 and A874V(c.2621C>T)on Exon 11.A new gene mutation sites was found,which was c.1708-5T>G.c.2294A>G on Exon 8 gene mutation tends to occur in patients with liver type.Patients with c.3517G>A mutation site on Exon 16 are more likely to develop FWD.3.Most of the patients with FWD were female.Patients mainly had elevated AST,ALP was significantly reduced in 4 patients,and three patients with a score greater than 11 had an ALP lower than 40U/L.The levels of serum copper,serum free copper and 24 h urine copper were significantly higher than those of non-FWD.The higher the serum free copper,the worse the prognosis.Among them,liver transplantation is the best treatment for patients with FWD with a prognostic score of ≥11.