Roles Of UGT1A1 Gene Mutation To The Development Of Neonatal Pathological Jaundice In Guangxi

Objective To establish Amplification Refractory Mutation System(ARMS) method for detecting G71R mutation of the UGT1A1 geneMethods(1)To establish a method of Amplification Refractory Mutation System(ARMS)for detecting G71R mutation of the UGT1A1 gene,to detect synchronous application of ARMS-PCR and direct sequencing method in 48 samples of G71R mutation with their correlation.(2)UGT1A1 G71R genotypes were identified by the newly developed ARMS in 110 pathological jaundice cases,and 31 healthy neonates after the relationship between them confirmed.(3) All full-term neonates related to their age,whose serum bilirubin equal or exceed to the limit of phototherapy or considered for phototherapy were diagnosed as pathological jaundice.Severe hyperbilirubinemia was diagnosed when a newborn infant had a peak bilirubin level =20.0 mg/dL in serum within 10 d of birth.Results(1)The results of ARMS-PCR and direct sequencing for 48 DNA samples were identical.(2)Out of 48 neonates detected by direct sequencing,5 neonates were with G71R homozygos type(10.42%),16 neonates with heterozygous type(33.33%)and 27 with wide types(56.25%).Out of 110 pathological jaundice neonates and 31 healthy neonates,9 neonates were genotypes of G71R homozygous variation(6.38%),36 neonates were heterozygous variation(25.53%),96 neonates were wide type(68.09%).(3)No significant statistics difference was noted for the constituent ratio of G71R genotypes and G71R allele frequencies between groups.Conclusion(1)It's the first time ARMS-PCR method was using to detect G71R mutation of UGT1A1 gene.Using direct sequencing in 48 neonates as gold standard,the results obtained by ARMS-PCR and direct sequencing were identical.(2)No significant statistic difference was noted for the constituent ratio of G71R genotypes and G71R allele frequencies obtained by two methods.(3)ARMS-PCR was with the benefits of simple,fast,and economic. Objective To investigate the roles of uridine diphosphate-glucuronosyl transferase 1A1(UGT1A1)gene mutation to the development of neonatal pathological jaundice in Guangxi,Methods for Analysis(1)To compare the G71R allele frequencies between neonatal pathological jaundice case and healthy control groups.(2)To compare the incidence of blirubin encephalopathy(kernicterus)and TSB concentration after 72 hours of age between different G71R genotype groups.(3)To analyse the risk factors of serum total bilirubin(TSB)that exceed 20mg/dl.(4)To identify the F83L genotype in 48 neonates.Results(1)The frequencies of allele gene G71R were 0.1915 in this study, 0.2329 in pathological jaundice neonates whose G6PD gene had no G1388A/ G1376T/A95G mutations as well as G6PD enzyme activity were normal,hence 0.097 was in healthy groups.The allele gene frequency of G71R in former group was higher than the latter,χ2=5.190,p=0.023.(2)The incidence of blirubin encephalopathy and TSB concentration after 72 hours of age for neonates who were homozygous to G71R gene was higher than the wide-type group(p=0o015 P＜0.001).(3)There were 5 neonates with TSB＞20mg/dl in G71R homozygous type,the odd ratio and 95%CI were 7.955(10349,46.899).(4)Out of 48 neonates detected by direct sequencing,nobody had F83L mutation.Conclusion(1)The incidence of blirubin encephalopathy and TSB concentration after 72 hours of age for neonates who were homozygous to G71R gene were higher than in the wide-type.(2)The chances of TSB＞20mg/dl in G71R homozygous was higher than the wide-type.(3)G71R mutation of UGT1A1 gene was associated with neonatal pathologic jaundice in Guangxi region.(4)There may be no existence of direct relationship between F83L mutation and neonatal jaundice in local place.