Phenotype and genotype analysis of progressive familial intrahepatic cholestasis type 4 / 中华实用儿科临床杂志

Objective:To improve the understanding of progressive familial intrahepatic cholestasis type 4 (PFIC4).Methods:Clinical characteristics in a 10-year-old boy with PFIC4 at the Second Hospital of Hebei Medical University in February 2020 were retrospectively analyzed, and the TJP2 gene mutations were analyzed. Results:The proband was a 10-year-old boy with a slow onset of intrahepatic cholestasis[normal γ-glutamyl transpeptidase(GGT)], hepatosplenomegaly and hepatic fibrosis.Laboratory tests showed elevated levels of total bilirubin, especially the direct bilirubin increased.Alanine aminotransferase, aspartate transaminase acid and total bile acid were elevated, while GGT remained in a normal range.Oral medication of ursodeoxycholic acid initially improved liver biochemical parameters, but later fluctuated.Adenosine dehydrogenase, coagulation indicators and hepatic fibrosis indexes were persistently abnormal.The average shear wave velocity of liver was 1.9 times of the upper limit of normal value.Compound heterozygous mutations c. 334G>A(p.A112T)/c.580_639delGACCGGAGCCGTGGCCGGAGCCTGGAGCGGGG-CCTGGACCAAGACCATGCGCGCACCCGA (p.194_213delDRSRGRSLERGLDQDHARTR) were found in the TJP2 gene.The deletion mutation of the TJP2 gene was reported for the first time throughout the world.Both of his parents carried a heterozygous mutation. Conclusions:PFIC should be considered in intrahepatic cholestasis patients with a normal range of GGT.The detection of TJP2 gene mutation is of great value in the clinical diagnosis of PFIC4.The presence of TJP2 gene mutation may be a risk factor for patient developing cirrhosis of liver and primary liver cancer in early childhood.It is necessary for children with PFIC4 to be closely followed up.

Clinical and DGUOK genetic analysis of a family with hepatocerebral mitochondrial DNA depletion syndrome / 中华实用儿科临床杂志

Objective:A retrospective analysis was performed on clinical characteristics and deoxyguanosine kinase DGUOK gene mutations in a family with hepatocerebral mitochondrial DNA depletion syndrome (MTDPS). Methods:The clinical data, treatment process and gene detection results of a child with MTDPS in the second hospital of Hebei Medical University in April 2019 were analyzed and summarized.Results:Proband was a girl.From the first week of infantile, she suffered from recurrent hypoglycemia, hyperlactic acid, progressive cholestatic liver dysfunction, coagulopathy, difficult feeding, slow growth of body mass, microcephaly, hypotonia, and gradul intermittent binocular tremors, and eventually failed to thrive.Gene testing identified two compound heterozygous mutations c. 42-c.43insTTCA(p.F15fs129X)/c.808-1(IVS6)G>A in DGUOK gene.The former was a frame-shift mutation resulted in truncated protein and the later was a splicing mutation resulted in abnormal splicing.Each parent was a heterozygous carrier, and there were no mutations in the two sites with her elder sister. Conclusions:Both mutations were first reported worldwide. DGUOK gene mutations with MTDPS are important causes of infant liver failure.When hypoglycemia, hyperlactic acidemia and liver dysfunction occur in newborn and infant, MTDPS related gene DGUOK gene sequencing screening should be considered for early definitive diagnosis, or, when acute liver failure happen in infant and childhood, neuromuscular involvement is insufficient.

Analysis of clinical characteristics and gene mutations in children with progressive familial intrahepatic cholestasis type 2 / 中华实用儿科临床杂志

Objective:To investigate clinical characteristics and ABCB11 gene mutations in probands suffering from progressive familial intrahepatic cholestasis type 2(PFIC2). Methods:The clinical data involving manifestations and laboratory examinations of 2 probands with PFIC2 admitted to Pediatric Digestive and liver Clinic in Second Hospital of Hebei Medical University during January 2017 to December 2018 were retrospectively analyzed.Target capture high-throughput sequencing, genome-wide gene copy number variation(CNV) detection and validation were performed on probands and their parental DNA.Results:The age of onset for the 2 probands ranged from 2 to 5 months, and they had hepatosplenomegaly, severe cholestasis, pruritus, and binding bilirubin/ total bilirubin (proband 1: 51.8%-77.5%, proband 2: 47.1%-66.5%). Bile acid and aminotransferase[mainly aspartate transaminase (AST)] increased, but γ-glutamyltransferase(GGT) remained normal.Compound heterozygous mutations of ABCBll gene were discovered in proband 1: single strand deletion/c.3213+ 5G>A splicing mutation, and deletion mutation were spontaneous mutation.A total of 2.256 Mb(chr2 2q24.3q31.1)was missing, whereas splicing mutation was originated from her father.Polymorphisms with Val444Ala(T1331C)and Ala1028Ala(A3084G)were proved in proband 1.Compound heterozygous mutations of ABCB11 gene were revealed in proband 2: c.1483A>G(p.R495G)/c.2594C>T(p.A865V), and both parents were heterozygous carriers.Single-strand 2.256 Mb deletion in proband 1 and 2 mutations in proband 2 were unreported new mutations worldwide. Conclusions:In clinical work, children with cholestasis, elevated bile acid and transaminase(mainly AST), but normal GGT, should be detected for PFIC genes as soon as possible.

Comparison of cstⅡ gene in Guillain-Barré syndrome-associated Campylobacter jejuni strains / 中华微生物学和免疫学杂志

Objective To investigate the pathogenic mechanism of Campylobacter jejuni(C.jejuni) associated with Guillain-Barré syndrome(GBS) and provide strategy for gene modification, the cstⅡ gene from 8 GBS-associated C.jejuni strains were compared with that from 3 GBS-unrelated C.jejuni strains, getting the base and amino acid mutations, the changes of secondary structures and finding the region which may be responsible for the pathogenicity of C.jejuni inducing GBS. Methods Three GBS-associated C.jejuni strains isolated from stools of GBS patients in north China were selected and cultured, which has been confirmed as GBS-associated by animal model. After sequencing the genome of them, the nucleotide sequences of cstⅡ gene were got through sequence alignment. The nucleotide sequences and deduced amini acid sequences of 3 GBS-associated cstⅡ genes were compared with that from 3 GBS-unrelated C.jejuni strains through bioinformatics software, getting the base and amino acid mutations, the changes of secondary structures. Other 5 GBS-associated cstⅡ genes were also aligned to know whether the differences we got above makes sense. In this way the genetic differences between two kinds of C.jejuni strains may be found and speculating the gene region related to the pathogenicity of GBS became possible. Results The cstⅡgene of 3 GBS-associated C.jejuni strains were all composed of 876 base pairs. Compared with GBS-unrelated C.jejuni strains, there were 9 consistent mutation sites in cstⅡ gene of LL and QYT stains, leading to 3 consistent amino acid mutation. The amino acid mutation of 114 and 182 sites in LL and QYT stains existed in other 5 GBS-associated C.jejuni strains. The sole amino acid mutation of ZHX strain -169 site, located near the 182 site. The seventh α-helix(165-180 region)of the secondary structure of the amino acid sequence from GBS-associated strains were shorter than that from GBS-unrelated strains, and the shorter regions were opened to form β-sheet or coli, which also existed in other GBS-related strains in this study.75% of the GBS-associated cstⅡ genes were Asn-51, while 25% of the GBS-associated and all of the GBS-unrelated cstⅡ genes were Thr-51.LL strain showed highly identity to other GBS-unrelated strains in this study. Conclusion The 165-180 segment of secondary structures in cstⅡ gene from local 3 GBS-associated C.jejuni strains are probably the responsible region involved in inducing GBS. The senior structure changes in this region may affect the activity of sialyltransferase and the structures of ganglioside epitope, so that the C.jejuni can acquire the pathogenicity of GBS. This finding may give a clue to genetic modified site. The bi-functional cstⅡ of C.jejuni may be related to the pathogenicity of GBS. The cstⅡ of LL strain to some extent represents the characteristics of Asian strains, which may directs strains monitoring.

Comparison of galE gene of Campylobacter jejuni strains associated Guillain-Barré syndrome / 中华微生物学和免疫学杂志

Objective To investigate the Camtrylobacterjejuni's risk factors which were associated with the development of Guillain-Barre syndrome( GBS), the galE gene of C. jejuni strains were sequenced and the sequencing results were compared with other C. jejuni strains. Methods Selecting three GBS-asso-ciated C.jejuni strains isolated from stools of GBS patients who had been diagnosed as AMAN pattern by clin-ical and electrophysiological test from Hebei province, China. After sequencing galE gene, the results were spliced and assembled into a complete sequence by the terminals overlapped each other. The sequences of galE gene were compared with the corresponding sequences in GenBank to find the mutation and constructed the phylogenetic tree. Results The variation frequency of galE sequences of GBS-associated C. jejuni were higher than that of non-GBS-associated C. jejuni. The phylogenetic analysis demonstrated that each of the three C. jejuni strains was separately genetically closed to three strains which sequences have published in GenBank. The alignment with the related sequence of NCTC11168 shows that there are 4 same mutations in the galE gene of the three C. jejuni strains. The phylogenic tree reflected the regional feature of C. jejuni. Conclusion The probability of sequence variation of galE of GBS-associated C.jejuni is significantly higher than non-GBS-associated C. jejuni strains, the relation between the variation and GBS-pathogenesis remains to be further confirmed. The mutations found in the three C. jejuni strains established the foundation for ex-ploring the biologically characteristic of GBS-associated C. jejuni strains.