HBV reactivation is commonly seen during immunosuppressive therapy and is associated with high incidence and mortality rates due to hepatitis outbreak and liver decompensation, and therefore, it should be taken seriously. However, the prevention and management of this potential complication is still a difficulty in clinical practice. This article reviews the diagnostic criteria and clinical outcomes of HBV reactivation, discusses the association of immunosuppressive therapy with the risk of HBV reactivation, and outlines the strategies for the prevention of HBV reactivation and recent advances. It is pointed out that early identification of patients with HBV infection before immunosuppressive therapy is of vital importance, and the initiation of antiviral therapy at the right moment based on risk stratification can effectively reduce the risk of HBV reactivation. We hope that this review can increase the awareness of HBV reactivation among clinicians and provide an effective reference for optimizing the management and prevention of HBV infection.

OBJECTIVETo explore the genetic cause of a Chinese boy with unexplained mental retardation, and analyze the pattern of inheritance for his family.

METHODSRoutine karyotyping, chromosomal microarray analysis (CMA), and fluorescence in situ hybridization (FISH) were used to detect chromosome abnormalities in the patient and his families.

RESULTSChromosome analysis suggested that the proband and 7 affected individuals had an identical karyotype 46,XN,der(22)t(3;22)(q28;q13)pat, while his father and 5 other relatives carried a same karyotype of 46,XN,t(3;22)(q28;q13). His mother and other family members were normal. CMA analysis confirmed that the patient had a 9.0 Mb duplication at 3q28q29, in addition with a 1.7 Mb deletion at 22q13.3. Above results were confirmed by FISH.

CONCLUSIONThe abnormal phenotypes of the proband and his family members from five generations have conformed to those of 3q duplication and 22q13.3 deletion caused by unbalanced translocation involving chromosomes 3q and 22q. The presence of multiple patients in this family may be attributed to abnormal gametes produced by parental balanced translocations involving 3q and 22q.

Chromosome Deletion ; Chromosome Duplication ; Chromosomes, Human, Pair 22 ; genetics ; Chromosomes, Human, Pair 3 ; genetics ; Cytogenetic Analysis ; methods ; Family Health ; Female ; Humans ; In Situ Hybridization, Fluorescence ; Infant ; Intellectual Disability ; genetics ; Karyotyping ; Male ; Pedigree ; Translocation, Genetic

OBJECTIVETo investigate the genetic cause for a child with developmental delay and congenital heart disease through molecular cytogenetic analysis.

METHODSG-banded karyotyping and chromosomal microarray analysis (CMA) were performed for the patient and his parents.

RESULTSThe proband's karyotype was detected as ring chromosome 3, and a 3q26.3-25.3 deletion encompassing 45 genes has been found with CMA. Testing of both parents was normal.

CONCLUSIONClinical phenotype of the patient with ring chromosome 3 mainly depends on the involved genes. It is necessary to combine CMA and karyotyping for the diagnosis of ring chromosome, as CMA can provide more accurate information for variations of the genome.

Chromosomes, Human, Pair 3 ; genetics ; Cytogenetic Analysis ; methods ; Cytogenetics ; methods ; Developmental Disabilities ; genetics ; Female ; Heart Defects, Congenital ; genetics ; Humans ; Infant ; Karyotyping ; methods ; Ring Chromosomes ; Syndrome

OBJECTIVETo explore the genetic cause for a boy featuring mainly with mental retardation.

METHODSG-banding karyotyping and fluorescence in situ hybridization (FISH) were carried out for the child and his parents. The child was also analyzed with chromosome microarray (CMA). Suspected microdeletion was validated with quantitative PCR.

RESULTSThe proband was found to have a 47,XYY karyotype by both chromosome and FISH analyses, while both of his parents had a normal karyotype. CMA suggested that the proband had one copy of X chromosome and two copies of Y chromosome. In addition, CMA has also detected deletion of the KYNU gene (mapped at 2q22.2), which could be pathogenic. The result was confirmed by qPCR.

CONCLUSIONFor its high resolution, CMA can be used to identify potential microdeletion/duplications among children with chromosome aneuploidy and unusual phenotypes.

Adult ; Child, Preschool ; Chromosome Banding ; Female ; Humans ; In Situ Hybridization, Fluorescence ; Intellectual Disability ; genetics ; Karyotyping ; Male ; Oligonucleotide Array Sequence Analysis ; methods ; Polymorphism, Single Nucleotide ; Sex Chromosome Disorders ; diagnosis ; genetics ; XYY Karyotype ; diagnosis ; genetics

OBJECTIVE: To explore the genetic basis for a child featuring short stature. METHODS: G-banded karyotyping, chromosomal microarray analysis (CMA) and high-throughput sequencing were carried out on peripheral blood sample from the child. RESULTS: The karyotype of the child was ascertained as 45,XY,-4[3]/46,XY,r(4)(p16q35)[84]/47,XY,-4,r(4)(p16q25)*2[7]/48,XY,-4,r(4)(p16q35)*3[1]/46,XY,dic r(4;4)(p16q35;p16q35)[2]/46,XY,add(4)(p16)[3]. A 647 kb deletion at 4p16.3 was identified by CMA, which encompassed 6 OMIM genes including ZNF141, PIGG, PDE6B, ATP5I, PCGF3 and MYL5. High-throughput sequencing has identified no pathogenic/likely pathogenic variants consistent with the clinical symptoms. CONCLUSION A rare ring chromosome 4 syndrome was identified by combined chromosomal karyotyping, CMA and high-throughput sequencing. Conventional cytogenetic analysis and genetic testing in combine have enabled the diagnosis in this case.

OBJECTIVE: To investigate the clinical and genetic features of a Chinese girl featuring mental retardation, intellectual disability, language development delay and epilepsy. METHODS: G-banded chromosomal karyotyping was carried out for the child. Genomic DNA of the patient and her parents was extracted and subjected to high-throughput sequencing. The results were analyzed with bioinformatic tools and validated by Sanger sequencing. RESULTS: The karyotype of the child was ascertained as 46,XX. Sequencing result showed that she has carried a de novo heterozygous c.1861C>T (p.R621X) variant of the SYNGAP1 gene. CONCLUSION The nonsense variant c.1861C>T (p.R621X) of the SYNGAP1 gene probably underlies the disease in this child. Above result has enabled genetic diagnosis and counseling for her family.

OBJECTIVE: To explore the genetic basis of a proband with distinctive facial features, global developmental delay, seizures and hypoplasia of corpus callosum through next generation sequencing (NGS). METHODS: Genomic DNA was extracted from peripheral blood samples of the proband and his family members. Whole exome and flanking sequences were screened by NGS. Suspected variants were verified by Sanger sequencing. RESULTS: The proband was found to carry a heterozygous c.2824G>T (p.G942X) variant of the ZEB2 gene, which was verified by Sanger sequencing to be a de novo variant. CONCLUSION The heterozygous c.2824G>T (p.G942X) variant of the ZEB2 gene probably underlies the Mowat-Wilson syndrome in the proband.
Facies ; Genetic Variation ; Heterozygote ; Hirschsprung Disease ; genetics ; Humans ; Intellectual Disability ; genetics ; Microcephaly ; genetics ; Whole Exome Sequencing ; Zinc Finger E-box Binding Homeobox 2 ; genetics

OBJECTIVE: To explore the clinical and genetic features of a patient with mental retardation. METHODS: G-Banding chromosomal karyotyping and high-throughput sequencing was carried out for the child. Suspected variant was validated in his family by Sanger sequencing and bioinformatic analysis. RESULTS: The patient was found to carry a de novo heterozygous c.4090G>T (p.Gly1364X) variant of the ASXL3 gene, which was known to predispose to Bainbridge-Ropers syndrome. CONCLUSION The nonsense c.4090G>T (p.Gly1364X) variant probably accounts for the disease in this patient.
Child ; Codon, Nonsense ; Developmental Disabilities ; genetics ; High-Throughput Nucleotide Sequencing ; Humans ; Intellectual Disability ; genetics ; Phenotype ; Syndrome ; Transcription Factors ; genetics

OBJECTIVE: To explore the genetic basis for a Chinese boy featuring developmental delay and epilepsy. METHODS: Clinical data of the patient was collected. Genomic DNA of the patient and his parents was extracted and subjected to high-throughput sequencing. Pathogenicity of the variant was predicted and validated. RESULTS: Sequencing results showed that the patient has carried a de novo c.1470delA (p.V491Ffs*6) variant of the UBE3A gene, which was predicted to be pathogenic. CONCLUSION The frameshift variant c.1470delA (p.V491Ffs*6) probably underlay the disorders in this child.

OBJECTIVE: To validate the diagnosis of an infant with elevated urine 3-methylglutaconic acid (3-MGA) through sequencing of the CLPB gene. METHODS: Genomic DNA of the infant was sequenced by next generation sequencing (NGS), and candidate pathogenic variants were verified by Sanger sequencing and bioinformatics analysis. RESULTS: NGS has revealed that the infant has carried a c.1085G>A (p.Arg362Gln) and a c.1700A>C (p.Tyr567Ser) of the CLPB gene, which were respectively inherited from her parents. Among these, c.1085G>A (p.Arg362Gln) is a novel variant which was unreported previously, and based on the ACMG guidelines, it was predicted to be a possible pathogenic variant. CONCLUSION Compound heterozygous variants c.1085G>A (p.Arg362Gln) and c.1700A>C (p.Tyr567Ser) of the CLPB gene probably underlay the disease in this infant. Genetic testing has confirmed the diagnosis.