Analysis of genetic variant in a child with Pitt-Hopkins syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child featuring facial dysmorphism, single palmar crease, motor and language delay, and hypoplasia of corpus callosum.@*METHODS@#A child who had visited the Affiliated Hospital of Binzhou Medical College on March 16, 2021 was selected as the study subject. Peripheral blood samples of the child and his parents were collected, and the genomic DNA was extracted for whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing and bioinformatic analysis.@*RESULTS@#WES revealed that the child has harbored a heterozygous c.607delT (p.S203Pfs*31) variant in exon 9 of the TCF4 gene, for which both of his parents were of the wild-type. Based on guidelines from the American College of Medical Genetics and Genomics, the variant was classified as pathogenic (PVS1+PM2_Supporting+PM6).@*CONCLUSION@#The heterozygous c.607delT (p.S203Pfs*31) variant of the TCF4 gene probably underlay the Pitt-Hopkins syndrome in this child. Genetic testing has enabled the definite diagnosis.

Analysis of a child with Very early onset inflammatory bowel disease due to compound heterozygous variants of IL10RA and DUOX2 genes / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis of a child with Very early onset inflammatory bowel disease (VEOIBD).@*METHODS@#A female child who had presented at the Children's Hospital of Fudan University on May 23, 2018 due to occurrence of diarrhea and fever 6 days after birth was selected as the study subject. Clinical data of the child was collected. Family-based whole-exome sequencing (WES) was carried out. Candidate variant was verified by Sanger sequencing and PCR of the patient and her parents.@*RESULTS@#The child had developed the symptoms 6 days after birth, with main manifestations including diarrhea, fever, failure to thrive, rectovestibular fistula and hypothyroidism. An enterostomy was performed at the age of 3.5 months due to severe intestinal adhesion and obstruction. Based on her clinical manifestations, colonoscopic finding, and results of biopsies, she was diagnosed with VEOIBD in conjunct with congenital hypothyroidism. Replacement treatment of levothyroxine was given since one month of age. Family-based WES revealed that the child has harbored compound heterozygous variants of the DUOX2 gene, namely c.2654G>T (p.R885L) and c.505C>T (p.R169W), in addition with a heterozygous c.301C>T (p.R101W) variant of the IL10RA gene. Re-analysis of the WES data revealed that the patient also had a 333 bp deletion spanning exon 1 of the IL10RA gene (Chr11: 117857034_117857366).@*CONCLUSION@#For patients with VEOIBD, genetic testing is recommended. Presence of additional DUOX2 gene variants might have exacerbated the clinical symptoms in this patient. Above finding has facilitated genetic counseling and prenatal diagnosis for this family, and raised clinicians' awareness of this rare disease.

Genetic analysis and in vitro validation of a case of Alport syndrome due to a splicing variant of COL4A5 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a patient with Alport syndrome (AS) and confirm the existence of a splicing variant.@*METHODS@#An AS patient diagnosed at the Affiliated Hospital of Inner Mongolia Medical University on January 8, 2021 for significant proteinuria and occult hematuria was selected as the study subject. Clinical data was collected. Peripheral blood samples were collected for the extraction of genomic DNA. Whole exome sequencing and Sanger sequencing were carried out to identify potential genetic variants. An in vitro experiment was also conducted to verify the abnormal mRNA splicing. Bioinformatic software was used to analyze the conservation of amino acids of the variant sites and simulate the 3D structure of the variant collagen IV protein. Immunofluorescence and immunohistochemistry were carried out on renal tissues from the patient to confirm the presence of AS kidney injury.@*RESULTS@#The patient, a 21-year-old male, had a 24-hour urine protein of 3.53 g/24 h, which fulfilled the diagnostic criteria for proteinuria. His blood uric acid has also increased to 491 μmol/L. DNA sequencing revealed that he has harbored a c.835-9T>A splice variant of the COL4A5 gene, which was not found in either of his parents. In vitro experiment confirmed that the variant has removed 57 bp from the exon 15 of the mRNA of the COL4A5 gene. The deletion may cause loss of amino acid residues from positions 279 to 297, which in turn may affect the stability of the secondary structure of the α5 chain encoded by the COL4A5 gene. The amino acids are conserved across various species. The result of homology modeling indicated that the trimerization of Col-IV with the mutated α5 chain could be achieved, however, the 3D structure was severely distorted. The AS kidney damage was confirmed through immunofluorescence assays. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.835-9T>A variant was classified as likely pathogenic (PVS1_Moderate+PS3_Moderate+PM2_Supporting+PS2+PP3+PP4).@*CONCLUSION@#The c.835-9T>A variant of the COL4A5 gene probably underlay the AS in this patient. In vitro experiment has confirmed the abnormal splicing caused by the variant. Histopathological examination of the kidney tissue has provided in vivo evidence for its pathogenicity. Above finding has expanded the mutational spectrum of the COL4A5 gene.

Analysis of a Chinese pedigree affected with Hereditary FⅫ deficiency due to compound heterozygous variants of F12 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the laboratory phenotype and molecular pathogenesis in a Chinese pedigree affected with Hereditary coagulation factor Ⅻ (FⅫ) deficiency.@*METHODS@#A male proband admitted to Ningbo No.2 Hospital on July 17, 2021 due to chronic gastritis and members of his pedigree (7 individuals from three generations) were selected as the study subjects. Prothrombin time (PT), activated partial thromboplastin time (APTT), FⅧ activity (FⅧ: C), FⅨ activity (FⅨ: C), FⅪ activity (FⅪ: C), FⅫ activity (FⅫ: C), and FⅫ antigen (FⅫ: Ag) were determined. All of the exons, exon-intronic boundaries, as well as the 5'- and 3'-untranslated regions of the F12 gene were subjected to Sanger sequencing. Candidate variants were verified by cloning sequencing. The effect of candidate variants on the protein function was analyzed by bioinformatics software.@*RESULTS@#The proband, a 47-year-old male, had significantly prolonged APTT (180.0 s) and decreased FⅫ:C and FⅫ:Ag levels (< 1%). His father, mother, brother and two sons also showed certain degrees of reduction. Genetic testing revealed that the proband has harbored compound heterozygous variants of the F12 gene, namely c.1092_1093insC (p.Lys365Glnfs*69) in exon 10 and c.1792_1796delGTCTA (p.Val579Hisfs*32) in exon 14. His mother and elder son were heterozygous for the c.1092_1093ins variant, whilst his father, brother, and younger son were heterozygous for the c.1792_1796delGTCTA variant. Analysis of the promoter region of exon 1 also showed that the proband and both sons had harbored a 46T/T polymorphism, whilst other family members were 46C/T. Bioinformatic analysis suggested that the p.Val579 is a highly conserved site. Protein model analysis showed that, with the p.Val579Hisfs*32 variant, a benzene ring was added and the hydrogen bond of surrounding amino acids was changed. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.1792_1796delGTCTA was classified as a pathogenic variant (PVS1+PM2_Supporting+PM4).@*CONCLUSION@#The c.1092_1093insC (p.Lys365Glnfs*69) and c.1792_1796delGTCTA (p.Val579Hisfs*32) compound heterozygous variants of the F12 gene probably underlay the decreased FXII levels in this pedigree. Above finding has also enriched the mutational spectrum for FⅫ deficiency.

Genetic analysis of an infant death due to a paternally derived FOXF1 somatic-gonadal mosaic variant / 中华医学遗传学杂志

OBJECTIVE@#To investigate the genetic characteristics and cause of death for an infant with alveolar capillary dysplasia and pulmonary vein misalignment (ACD/MPV).@*METHODS@#An infant with ACD/MPV diagnosed at the Affiliated Maternity and Child Health Care Hospital of Nantong University in September 2022 was selected as the study subject. Clinical data of the infant were collected. Whole exome sequencing (WES) was carried out to detect genetic variants in the skin tissue, and Sanger sequencing was performed for verifying the candidate variants in the parents. Droplet digital PCR (ddPCR) was used to determine the mosaicism ratio of the variant in different germ layer-derived samples from the father.@*RESULTS@#The infant had died within 2 days after birth due to hypoxemia and respiratory distress. WES revealed that she has harbored a c.433C>T nonsense variant in exon 1 of the FOXF1 gene, which was unreported previously. Sanger sequencing has verified the variant in the infant, with her mother's locus being the wild-type and a minor variant peak noted in her father. ddPCR indicated that the mosaic ratio of the c.433C>T variant in the father's sperm was 27.18%, with the mosaic ratios of the variant in tissues originating from the three germ layers ranging from 11% to 28%.@*CONCLUSION@#The c.433C>T variant derived from the paternal germline and somatic mosaicism of the FOXF1 gene had probably predisposed to the neonatal death of this infant. ddPCR is an effective method for detecting mosaic variants.

Analysis of ARX gene variant in a child with X-linked lissencephaly with abnormal genitalia / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical characteristics and genetic basis for a child with X-linked lissencephaly with abnormal genitalia (XLAG).@*METHODS@#A child with XLAG who had presented at the Third Affiliated Hospital of Zhengzhou University in May 2021 was selected as the study subject. Peripheral blood samples of the child and his parents were collected and subjected to high-throughput sequencing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the result was analyzed by using bioinformatic software.@*RESULTS@#The child was found to have harbored a hemizygous c.945_948del variant in exon 2 of the ARX gene, which as a frameshifting variant has resulted in a truncated protein. His mother was found to be heterozygous for the variant, whilst his father was of wild type. The variant was unreported previously.@*CONCLUSION@#The hemizygous c.945_948del variant of the ARX gene probably underlay the XLAG in this patient. Above finding has provided a basis for the diagnosis and genetic counseling for this family.

Genetic diagnosis of Branchio-Oto syndrome pedigree due to a de novo heterozygous deletion of EYA1 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree affected with Branchio-Oto syndrome (BOS).@*METHODS@#A pedigree with BOS which had presented at the Genetics and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University in May 2021 was selected as the study subject. Clinical data of the pedigree was collected. Peripheral blood samples of the proband and her parents were collected. Whole exome sequencing (WES) was carried out for the proband. Multiplex ligation-dependent probe amplification (MLPA) was used to verify the result of WES, short tandem repeat (STR) analysis was used to verify the relationship between the proband and her parents, and the pathogenicity of the candidate variant was analyzed.@*RESULTS@#The proband, a 6-year-old girl, had manifested severe congenital deafness, along with inner ear malformation and bilateral branchial fistulae. WES revealed that she has harbored a heterozygous deletion of 2 466 kb at chromosome 8q13.3, which encompassed the EYA1 gene. MLPA confirmed that all of the 18 exons of the EYA1 gene were lost, and neither of her parents has carried the same deletion variant. STR analysis supported that both of her parents are biological parents. Based on the guidelines from the American College of Medical Genetics and Genomics, the deletion was classified as pathogenic (PVS1+PS2+PM2_Supporting+PP4).@*CONCLUSION@#The heterozygous deletion of EYA1 gene probably underlay the pathogenicity of BOS in the proband, which has provided a basis for the clinical diagnosis.

Expert Consensus on Targeted Therapy of NSCLC with MET Exon 14 Skipping Mutation / 中国肺癌杂志

The mesenchymal-epithelial transition factor (MET) exon 14 skipping mutation is mainly caused by the loss of c-Cbl tyrosine binding site. This mutation could result in a decrease in the degradation rate of proteasome-mediated MET proteins, trigger continuous activation of downstream pathways, and ultimately lead to tumorigenesis. The incidence of MET exon 14 skipping mutation in patients with non-small cell lung cancer (NSCLC) is 0.9% to 4.0%. Patients with advanced NSCLC are recommended to test MET exon 14 skipping mutations who may benefit from MET inhibitors-targeted therapy. MET inhibitors have a high objective response rate and good safety profiles, which could prolong the survival of NSCLC patients with MET exon 14 skipping mutations. The Lung Cancer Specialty Committee of Chinese Elderly Health Care Association organized multidisciplinary experts to give suggestions on the important issues of clinical aspects for targeted therapy of MET exon 14 skipping mutation in NSCLC according to the clinical practice experiences and evidences based medicine. "Expert Consensus on Targeted Therapy of NSCLC with MET Exon 14 Skipping Mutation" is proposed, aiming to provide standardized guidances for the clinical practice of Chinese physicians.
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Chinese Expert Consensus on Non-small Cell Lung Cancer with EGFR Exon 20 Insertion Mutations (2023 Edition) / 中国肺癌杂志

With the development of precision diagnosis and treatment for non-small cell lung cancer (NSCLC), the epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations, as a rare subset of EGFR mutaions, have gradually attracted attention recently. The heterogeneity of EGFR ex20ins mutations is very high, different variants have different clinical benefits, and the prognosis is extremely poor. The available traditional treatment outcomes are poor in patients with EGFR ex20ins positive NSCLC and polymerase chain reaction (PCR) tests would miss aprocimately 50% of the variants. Therefore, high attention should be paid to EGFR ex20ins positive NSCLC during the clinical practice. The expert panel has formed a consensus on the standardized clinical diagnosis and treatment of EGFR ex20ins mutation NSCLC through reference to literature and clinical data, and combined with the experts' own clinical experience, the consensus recommendations including clinicopathologic characteristics, therapies, testing methods and recent relevant clinical trials for NSCLC patients with EGFR ex20ins mutation, in order to provide medication reference for clinical physicians at all levels.

RHD Gene Analysis of A Blood Donor with Del Phenotype / 中国实验血液学杂志

OBJECTIVE@#To analyze the RHD genotype of a blood donor with Del phenotype in Yunnan.@*METHODS@#Rh serological phenotype was identified. RHD gene was detected by PCR-SSP typing, and its 10 exons were sequenced. Exon 9 was amplified for sequencing and analysis. RHD zygosity was detected.@*RESULTS@#The Rh phenotype of this specimen was CcDelee. Genomic DNA exhibited a 1 003 bp deletion spanning from intron 8, across exon 9 into intron 9. The deletion breakpoints occurred between two 7-bp short tandem repeat sequences. There was no variation in the sequences of the remaining exons. The Rh hybridization box test showed that there was one RHD negative allele.@*CONCLUSION@#This specimen is Del type caused by deletion of RHD exon 9.

Analysis of a child with X-linked intellectual disability due to a maternal de novo splicing variant of the PAK3 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic etiology for a child with profound intellectual disabilities and obvious behavioral abnormalities.@*METHODS@#A male child who had presented at the Zhongnan Hospital of Wuhan University on December 2, 2020 was selected as the study subject. Peripheral blood samples of the child and his parents were collected and subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing. Short tandem repeat (STR) analysis was carried out to determine its parental origin. The splicing variant was also validated in vitro with a minigene assay.@*RESULTS@#WES results revealed that the child had harbored a novel splicing variant of c.176-2A>G in the PAK3 gene, which was inherited from his mother. The results of minigene assay have confirmed aberrant splicing of exon 2. According to the guidelines from the American College of Medical Genetics and Genomics, it was classified as a pathogenic variant (PVS1+PM2_Supporting+PP3).@*CONCLUSION@#The novel splicing variant c.176-2A>G of the PAK3 gene probably underlay the disorder in this child. Above finding has expanded the variation spectrum of the PAK3 gene and provided a basis for genetic counseling and prenatal diagnosis for this family.

Clinical manifestations and genetic analysis of 4 patients with variants of FBN1 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for four patients suspected for Marfan syndrome (MFS).@*METHODS@#Four male patients with suspected MFS and their family members who were treated at West China Second Hospital of Sichuan University from September 12, 2019 to March 27, 2021 were selected as the study subjects. Peripheral venous blood samples were collected from the patients and their parents or other pedigree members for the extraction of genomic DNA. Whole exome sequencing was carried out, and candidate variants were validated by Sanger sequencing. The pathogenicity of the variants was determined based on the guidelines from the American College of Medical Genetics and Genomics (ACMG).@*RESULTS@#Genetic testing revealed that all four patients have harbored variants of the FBN1 gene, including c.430_433del (p.His144fs) deletional variant in exon 5, c.493C>T (p.Arg165*) nonsense variant in exon 6, c.5304_5306del (p.Asp1768del) deletional variant in exon 44 and c.5165C>G (p.Ser1722Cys) missense variant in exon 42. According to the ACMG guidelines, the c.430_433del and c.493C>T were classified as pathogenic variants (PVS1+PM2_Supporting+PP4; PVS1+PS1+PS2+PM2_Supporting+PP4). c.5304_5306del and c.5165C>G were classified as likely pathogenic variants (PS2+PM2_Supporting+PM4+PP4; PS2_Moderate+PS1+PM1+PM2_Supporting).@*CONCLUSION@#The c.430_433del and c.5304_5306del variants of the FBN1 gene identified in this study were unreported previously. Above results have enriched the variation spectrum of the FBN1 gene and provided a basis for genetic counseling and prenatal diagnosis of patients with MFS and acromicric dysplasia.

Clinical and genetic analysis of three children with Menkes disease due to variants of ATP7A gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical characteristics and genetic etiology of three children with Menkes disease.@*METHODS@#Three children who had presented at the Children's Medical Center, the Affiliated Hospital of Guangdong Medical University from January 2020 to July 2022 were selected as the study subjects. Clinical data of the children were reviewed. Genomic DNA was extracted from peripheral blood samples of the children, their parents and sister of child 1. Whole exome sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing, copy number variation sequencing (CNV-seq), and bioinformatic analysis.@*RESULTS@#Child 1 was a 1-year-and-4-month male, and children 2 and 3 were monozygotic twin males aged 1-year-and-10-month. The clinical manifestations of the three children have included developmental delay and seizures. WES showed that child 1 has harbored a c.3294+1G>A variant of the ATP7A gene. Sanger sequencing confirmed that his parents and sister did not carry the same variant, suggesting that it was de novo. Children 2 and 3 had carried a c.77266650_77267178del copy number variation. CNV-seq results showed that their mother has carried the same variant. By searching the HGMD, OMIM and ClinVar databases, the c.3294+1G>A was known to be pathogenic. No carrier frequency has been recorded in the 1000 Genomes, ESP, ExAC and gnomAD databases. Based on the Standards and Guidelines for the Interpretation of Sequence Variants: A Joint Consensus Recommendation of the American College of Medical Genetics and Genomics (ACMG), the ATP7A gene c.3294+1G>A variant was predicted to be pathogenic. The c.77266650_77267178del variant has involved exons 8 to 9 of the ATP7A gene. ClinGen online system score for it was 1.8, which was also considered to be pathogenic.@*CONCLUSION@#The c.3294+1G>A and c.77266650_ 77267178del variants of the ATP7A gene probably underlay the Menkes disease in the three children. Above finding has enriched the mutational spectrum of Menkes disease and provided a basis for clinical diagnosis and genetic counseling.

Genetic analysis of a case with 11β hydroxylase deficiency caused by CYP11B2/CYP11B1 chimeric gene / 中华医学遗传学杂志

OBJECTIVE@#To analyze a child with 11β hydroxylase deficiency (11β-OHD) due to CYP11B2/CYP11B1 chimeric gene.@*METHODS@#Clinical data of the child who was admitted to Henan Children's Hospital on August 24, 2020 were retrospectively analyzed. Peripheral blood samples of the child and his parents were collected and subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing. RT-PCR and Long-PCR were carried out to verify the presence of chimeric gene.@*RESULTS@#The patient, a 5-year-old male, had featured premature development of secondary sex characteristics and accelerated growth, and was diagnosed with 21 hydroxylase deficiency (21-OHD). WES revealed that he has harbored a heterozygous c.1385T>C (p.L462P) variant of the CYP11B1 gene, in addition to a 37.02 kb deletion on 8q24.3. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.1385T>C (p.L462P) was rated as a likely pathogenic variant (PM2_Supporting+PP3_Moderate+PM3+PP4). The results of RT-PCR and Long-PCR suggested that CYP11B1 and CYP11B2 genes have recombined to form a CYP11B2 exon 1~7/CYP11B1 exon 7~9 chimeric gene. The patient was diagnosed as 11β-OHD and effectively treated with hydrocortisone and triptorelin. A healthy fetus was delivered following genetic counseling and prenatal diagnosis.@*CONCLUSION@#11β-OHD may be misdiagnosed as 21-OHD due to the potential CYP11B2/CYP11B1 chimeric gene, which will require multiple methods for the detection.

Genetic analysis and reproductive intervention of 7 families with gonadal mosaicism for Duchenne muscular dystrophy / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for 7 families with gonadal mosaicism for Duchenne muscular dystrophy (DMD).@*METHODS@#For the 7 families presented at the CITIC Xiangya Reproductive and Genetic Hospital from September 2014 to March 2022, clinical data were collected. Preimplantation genetic testing for monogenic disorders (PGT-M) was carried out for the mother of the proband from family 6. Peripheral venous blood samples of the probands, their mothers and other patients from the families, amniotic fluid samples from families 1 ~ 4 and biopsied cells of embryos cultured in vitro from family 6 were collected for the extraction of genomic DNA. Multiplex ligation-dependent probe amplification (MLPA) was carried out for the DMD gene, and short tandem repeat (STR)/single nucleotide polymorphism (SNP)-based haplotypes were constructed for the probands, other patients, fetuses and embryos.@*RESULTS@#The results of MLPA showed that the probands and the fetuses/probands' brothers in families 1 ~ 4, 5, 7 had carried the same DMD gene variants, whilst the probands' mothers were all normal. The proband in family 6 carried the same DMD gene variant with only 1 embryo (9 in total) cultured in vitro, and the DMD gene of the proband's mother and the fetus obtained through the PGT-M were normal. STR-based haplotype analysis showed that the probands and the fetuses/probands' brothers in families 1 ~ 3 and 5 have inherited the same maternal X chromosome. SNP-based haplotype analysis showed that the proband from family 6 has inherited the same maternal X chromosome with only 1 embryo (9 in total) cultured in vitro. The fetuses in families 1 and 6 (via PGT-M) were both confirmed to be healthy by follow up, whilst the mothers from families 2 and 3 had chosen induced labor.@*CONCLUSION@#Haplotype analysis based on STR/SNP is an effective method for judging gonad mosaicism. Gonad mosaicisms should be suspected for women who have given births to children with DMD gene variants but with a normal peripheral blood genotype. Prenatal diagnosis and reproductive intervention may be adapted to reduce the births of further affected children in such families.

Splicing abnormalities caused by a novel mutation in the PHKA2 gene in children with glycogen storage disease type IX / 中华肝脏病杂志

Objective: Glycogen storage disease type IX (GSD-IX) is a rare primary glucose metabolism abnormality caused by phosphorylase kinase deficiency and a series of pathogenic gene mutations. The clinical characteristics, gene analysis, and functional verification of a mutation in a child with hepatomegaly are summarized here to clarify the pathogenic cause of the disease. Methods: The clinical data of a child with GSD-IX was collected. Peripheral blood from the child and his parents was collected for genomic DNA extraction. The patient's gene diagnosis was performed by second-generation sequencing. The suspected mutations were verified by Sanger sequencing and bioinformatics analysis. The suspected splicing mutations were verified in vivo by RT-PCR and first-generation sequencing. Results: Hepatomegaly, transaminitis, and hypertriglyceridemia were present in children. Liver biopsy pathological examination results indicated glycogen storage disease. Gene sequencing revealed that the child had a c.285 + 2_285 + 5delTAGG hemizygous mutation in the PHKA2 gene. Sanger sequencing verification showed that the mother of the child was heterozygous and the father of the child was of the wild type. Software such as HSF3.1 and ESEfinder predicted that the gene mutation affected splicing. RT-PCR of peripheral blood from children and his mother confirmed that the mutation had caused the skipping of exon 3 during the constitutive splicing of the PHKA2 gene. Conclusion: The hemizygous mutation in the PHKA2 gene (c.285 + 2_285 + 5delTAGG) is the pathogenic cause of the patient's disease. The detection of the novel mutation site enriches the mutation spectrum of the PHKA2 gene and serves as a basis for the family's genetic counseling.

Diagnosis status and genetic characteristics analysis of Fanconi anemia in China / 中华儿科杂志

Objective: To analyze the clinical and molecular diagnostic status of Fanconi anemia (FA) in China. Methods: The General situation, clinical manifestations and chromosome breakage test and genetic test results of 107 pediatric FA cases registered in the Chinese Blood and Marrow Transplantation Registry Group (CBMTRG) and the Chinese Children Blood and Marrow Transplantation Registry Group (CCBMTRG) from August 2009 to January 2022 were analyzed retrospectively. Children with FANCA gene variants were divided into mild and severe groups based on the type of variant, and Wilcoxon-test was used to compare the phenotypic differences between groups. Results: Of the 176 registered FA patients, 69 (39.2%) cases were excluded due to lack of definitive genetic diagnosis results, and the remaining 107 children from 15 hospitals were included in the study, including 70 males and 37 females. The age at transplantation treatment were 6 (4, 9) years. The enrolled children were involved in 10 pathogenic genes, including 89 cases of FANCA gene, 7 cases of FANCG gene, 3 cases of FANCB gene, 2 cases of FANCE gene and 1 case each of FANCC, FANCD1, FANCD2, FANCF, FANCJ, and FANCN gene. Compound heterozygous or homozygous of loss-of-function variants account for 69.2% (72/104). Loss-of-function variants account for 79.2% (141/178) in FANCA gene variants, and 20.8% (37/178) were large exon deletions. Fifty-five children (51.4%) had chromosome breakage test records, with a positive rate of 81.8% (45/55). There were 172 congenital malformations in 80 children.Café-au-Lait spots (16.3%, 28/172), thumb deformities (16.3%,28/172), polydactyly (13.9%, 24/172), and short stature (12.2%, 21/172) were the most common congenital malformations in Chinese children with FA. No significant difference was found in the number of congenital malformations between children with severe (50 cases) and mild FANCA variants (26 cases) (Z=-1.33, P=0.185). Conclusions: FANCA gene is the main pathogenic gene in children with FA, where the detection of its exon deletion should be strengthened clinically. There were no phenotypic differences among children with different types of FANCA variants. Chromosome break test is helpful to determine the pathogenicity of variants, but its accuracy needs to be improved.

Advances in the Treatment of EGFR Exon 20ins Mutant NSCLC / 中国肺癌杂志

Lung cancer has become one of the most dangerous cancers to human health and the mortality rate is the highest among all the causes of cancer death. Non-small cell lung cancer (NSCLC) accounts for about 80%-85% of lung cancer. Chemotherapy is the main treatment for advanced NSCLC, but the 5-year survival rate is low. Epidermal growth factor receptor (EGFR) mutations are the most common driver mutations in lung cancer, but EGFR exon 20 insertions (EGFR ex20ins) mutation belongs to one of the rare mutations, accounting for about 4%-10% of overall EGFR mutations, thus around 1.8% of advanced NSCLC patients. In recent years, targeted therapies represented by EGFR tyrosine kinase inhibitors (TKIs) have become an important treatment option for patients with advanced NSCLC, however, NSCLC patients with EGFR ex20ins mutation are not sensitive to most of EGFR-TKIs treatments. Currently, some of the targeted drugs for EGFR ex20ins mutation have achieved significant efficacy, while some of them are still under clinical investigation. In this article, we will describe various treatment methods for EGFR ex20ins mutation and their efficacy.
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Progress in Detection of EGFR Exon 20 Insertion Mutation and Targeted Therapies in Non-small Cell Lung Cancer / 中国肺癌杂志

Epidermal growth factor receptor exon 20 insertion (EGFR ex20ins) is one of the earliest driver gene activation mutations in non-small cell lung cancer (NSCLC). However, due to the unique structure of protein variation caused by this mutation, most patients with EGFR ex20ins mutation (except A763_Y764insFQEA) have poor response to the launched first/second/third generation EGFR-tyrosine kinase inhibitors (EGFR-TKIs). With the successive approval of new specific targeted drugs for EGFR ex20ins in Food and Drug Administration (FDA) and other national regulatory agencies, the development and clinical research of targeted drugs for EGFR ex20ins in China have also developed rapidly and Mobocertinib has been approved recently in China. It is worth noting that EGFR ex20ins is a variant type with strong molecular heterogeneity. How to detect it comprehensively and accurately in clinical practice, so as to enable more patients to benefit from targeted therapy, is a very important and urgent problem to be solved. This review introduces the molecular typing of EGFR ex20ins, then discusses the importance of EGFR ex20ins detection and the differences of various detection methods, and summarizes the research and development of new drugs progress of EGFR ex20ins, in order to optimize the diagnosis and treatment path of EGFR ex20ins patients by selecting accurate, rapid and appropriate detection methods, so as to improve the clinical benefits of the patients.
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A case of Rubinstein-Taybi syndrome caused by a variant of EP300 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical characteristics and genetic etiology of a child with Rubinstein-Taybi syndrome (RSTS).@*METHODS@#A child who was admitted to the Children's Hospital of Soochow University on October 3, 2021 was selected as the study subject. Clinical data of the child was collected. Peripheral blood samples of the child and his parents were collected. The child was subjected to whole exome sequencing (WES), and candidate variant was verified by Sanger sequencing of his family members and bioinformatic analysis.@*RESULTS@#The patient, a 9-year-and-４-month-old boy, had manifested unique facies, microcephaly, broad toes, growth retardation, and intellectual impairment. WES revealed that he has harbored a heterozygous c.3604G>T (p.E1202*) variant in exon 20 of the EP300 gene. Sanger sequencing confirmed that neither of his parents has carried the same variant. The variant was not found in the Shenzhou Genome data Cloud, ExAC, 1000 Genomes and gnomAD databases．Analysis with SIFT, PolyPhen-2 and CADD online software has predicted the variant to be harmful. Based on the guidelines formulated by the American College of Medical Genetics and Genomics, the variant was rated as pathogenic (PVS1＋PS2＋PM2_Supporting) .@*CONCLUSION@#The heterozygous c.3604G>T variant of the EP300 gene probably underlay the RSTS type 2 in this child. Above finding has also expanded the variation spectrum of the EP300 gene.