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.
Male ; Female ; Humans ; Child ; Fanconi Anemia/genetics* ; Chromosome Breakage ; Retrospective Studies ; Exons ; China/epidemiology*

Whether Fanconi anemia (FA) heterozygotes are predisposed to bone marrow failure and hematologic neoplasm is a crucial but unsettled issue in cancer prevention and family consulting. We retrospectively analyzed rare possibly significant variations (PSVs) in the five most obligated FA genes, BRCA2, FANCA, FANCC, FANCD2, and FANCG, in 788 patients with aplastic anemia (AA) and hematologic malignancy. Sixty-eight variants were identified in 66 patients (8.38%). FANCA was the most frequently mutated gene (n = 29), followed by BRCA2 (n = 20). Compared with that of the ExAC East Asian dataset, the overall frequency of rare PSVs was higher in our cohort (P = 0.016). BRCA2 PSVs showed higher frequency in acute lymphocytic leukemia (P = 0.038), and FANCA PSVs were significantly enriched in AA and AML subgroups (P = 0.020; P = 0.008). FA-PSV-positive MDS/AML patients had a higher tumor mutation burden, higher rate of cytogenetic abnormalities, less epigenetic regulation, and fewer spliceosome gene mutations than those of FA-PSV-negative MDS/AML patients (P = 0.024, P = 0.029, P = 0.024, and P = 0.013). The overall PSV enrichment in our cohort suggests that heterozygous mutations of FA genes contribute to hematopoietic failure and leukemogenesis.
Anemia, Aplastic/genetics* ; Epigenesis, Genetic ; Fanconi Anemia/genetics* ; Germ Cells ; Hematologic Neoplasms/genetics* ; Humans ; Leukemia, Myeloid, Acute/genetics* ; Retrospective Studies

DNA ; DNA Damage ; DNA Repair ; Fanconi Anemia/genetics* ; Humans

BACKGROUND: Lung cancer is the main cause of cancer-related death globally. Single nucleotide polymorphism (SNP) is one of the important factors leading to the occurrence of lung cancer, but its mechanism has not been elucidated. This study intends to investigate the relationship between SNPs of CDH1, FANCB, APC genes and lung cancer genetic susceptibility. METHODS: The case-control study design was used. We collected blood samples from 270 lung cancer cases in the Department of Lung Cancer Surgery, Tianjin Medical University General Hospital, as well as blood samples from 445 healthy volunteers as controls, and extracted genomic DNA for genotyping using the Taqman® SNP genotyping kit. The distribution of three SNP loci of CDH1 gene rs201141645, FANCB gene rs754552650 and APC gene rs149353082 in Chinese population was analyzed. Chi-square test and Logistic regression were used to analyze the relationship between different genotypes and the risk of lung cancer. RESULTS: The distribution frequencies of AA, A/G and GG genotypes at rs754552650 of FANCB gene in the control group were 27.2%, 52.6% and 20.2%, respectively. The distribution frequencies of AA and A/G genotypes were 93.7% and 6.3% in the case group, respectively, and no GG genotype was detected. The A/G genotype of the rs754552650 locus of the FANCB gene was significantly different between the case group and the control group. Compared with the carriers of AA genotype, the individuals with FANCB rs754552650 A/G genotype had a lower risk of lung cancer (OR=0.035, 95%CI: 0.020-0.062, P<0.001). CDH1 gene rs201141645 A/C and CC genotypes only existed in the control group. In addition, only 1 sample was found to have APC rs149353082 genotype in the case group. CONCLUSIONS In the Chinese population, the lung cancer risk of the individuals with FANCB rs754552650 A/G genotype was significantly decreased.
Antigens, CD/genetics* ; Cadherins/genetics* ; Case-Control Studies ; China ; Fanconi Anemia Complementation Group Proteins/genetics* ; Gene Frequency ; Genes, APC ; Genetic Predisposition to Disease ; Genotype ; Humans ; Lung Neoplasms/genetics* ; Polymorphism, Single Nucleotide

OBJECTIVE: To explore the genetic basis of a child affected with refractory leukocytopenia and thrombocytopenia. METHODS: Clinical manifestation and auxiliary examination of the child were discussed. Whole exome next generation sequencing (NGS) and multiplex ligation-dependent probe amplification (MLPA) were used to detected potential mutations of the FANCA gene. RESULTS: Repeated blood tests indicated that the child had abnormal WBC count at (2.7-3.98)×10^9;/L, platelet at (33-81) ×10^9;/L and hemoglobin at (100-120) g/L. NGS showed that she and her mother both carried a heterozygous c.3181A>G mutation (non-pathogenic) and a c.3788_3790del mutation of the FANCA gene. MLPA showed that she and her father both had heterozygous deletion of exons 11 to 14 of the FANCA gene. CONCLUSION The compound heterozygous mutations of c.3788_3790del and deletion of exons 11 to 14 of the FANCA gene probably underlie the refractory leukocytopenia and thrombocytopenia in the child.
Child ; Exons ; Fanconi Anemia Complementation Group A Protein ; genetics ; Female ; Heterozygote ; Humans ; Leukopenia ; genetics ; Mutation ; Thrombocytopenia ; genetics

OBJECTIVETo investigate the association between clinical outcome and gene mutations in children with Fanconi anemia (FA).

METHODSA retrospective analysis was performed for the clinical data of six children with the same severity of FA and receiving the same treatment. At first, single cell gel electrophoresis and chromosome breakage induced by mitomycin C were performed for diagnosis. Then the gene detection kit for congenital bone marrow failure diseases or complementation test was used for genotyping of FA. Finally the association between the clinical outcome at 3, 6, 9, or 12 months after treatment and gene mutation was analyzed.

RESULTSOf all the six FA children, five had FANCA type disease, and one had FANCM type disease; four children carried two or more FA gene mutations. Among the children with the same severity of FA, those with more FA mutations had a younger age of onset and poorer response to medication, and tended to progress to a severe type.

CONCLUSIONSChildren carrying more than two FA mutations have a poor clinical outcome, and hematopoietic stem cell transplantation should be performed as soon as possible.

Child ; Child, Preschool ; Fanconi Anemia ; genetics ; Female ; Humans ; Male ; Mutation ; Retrospective Studies

OBJECTIVETo provide prenatal diagnosis for a pregnant woman who had given birth to a child with Fanconi anemia with combined next-generation sequencing (NGS) and Sanger sequencing.

METHODSFor the affected child, potential mutations of the FANCA gene were analyzed with NGS. Suspected mutation was verified with Sanger sequencing. For prenatal diagnosis, genomic DNA was extracted from cultured fetal amniotic fluid cells and subjected to analysis of the same mutations.

RESULTSA low-frequency frameshifting mutation c.989_995del7 (p.H330LfsX2, inherited from his father) and a truncating mutation c.3971C>T (p.P1324L, inherited from his mother) have been identified in the affected child and considered to be pathogenic. The two mutations were subsequently verified by Sanger sequencing. Upon prenatal diagnosis, the fetus was found to carry two mutations.

CONCLUSIONThe combined next-generation sequencing and Sanger sequencing can reduce the time for diagnosis and identify subtypes of Fanconi anemia and the mutational sites, which has enabled reliable prenatal diagnosis of this disease.

Adult ; Base Sequence ; Child, Preschool ; DNA Mutational Analysis ; Fanconi Anemia ; diagnosis ; genetics ; Fanconi Anemia Complementation Group A Protein ; genetics ; Female ; Fetal Diseases ; diagnosis ; genetics ; High-Throughput Nucleotide Sequencing ; Humans ; Male ; Molecular Sequence Data ; Mutation ; Polymorphism, Single Nucleotide ; Pregnancy ; Prenatal Diagnosis

OBJECTIVETo enrich our national database with data of rare diseases by analyzing molecular diagnosis and hematopoietic stem cell transplantation (HSCT) in children with inherited bone marrow failure syndromes (IBMFS).

METHODNext-generation sequencing (NGS)-based genetic diagnosis panel was applied for the clinical diagnosis and management of IBMFS. Retrospective analysis was performed on clinical and genetic data of 17 consecutive children who received HSCT over a long time interval (November. 2005-June 2015).

RESULTThree patients were diagnosed only by clinical manifestation before 2012. After that NGS-based genetic diagnosis panel was used to identify IBMFS-related genes in 12/14.IBMFS patients (except two Diamond-Blackfan anemia (DBA) patients). Two Fanconi anemia (FA) patients were confirmed to be new variations through family-genotype-analysis and 3 families accepted prenatal diagnosis to avoid birth of affected fetuses. Seventeen IBMFS patients (10 FA,5 DBA and 2 dyskeratosis congenital (DKC)) were treated with HSCT from matched sibling donors (n=2), matched unrelated donors (n=8) or mismatched unrelated donors (n=7). The source of stem cells for transplantation included peripheral blood (n=12) and cord blood (n=5). With regard to the conditioning regimens, FA and DKC patients received fludarabine-based reduced intensity conditioning, while DBA patients received classical busulfan-based myeloablative conditioning. Median age at the time of HSCT was 36 months (7-156 months). The number of infused mononuclear cells and CD34⁺ cells was (10.6 ± 6.7) × 10⁸ and (5.9 ± 7.0) × 10⁶ per kilogram of recipient body weight, respectively. The median number of days to neutrophil recovery was 13 days after HSCT (range: 10-19 days). Platelet recovery was faster in the PBSCT group than in the CBT group ((16.3 ± 6.0) days vs. (30.0 ± 17.1) days,t=-2.487,P=0.026). During a median follow-up of 17 months (range: 2-114 months), except one FA patient who was transplanted with HLA-matched unrelated cord blood (CB) died from pneumonia and heart failure because of engraftment failure, other 16 children are alive after the successful HSCT. The failure-free survival rate of the patients three years after HSCT was 94%.

CONCLUSIONNGS-based molecular diagnosis technology and effective HSCT have significantly facilitated the treatment of children with IBMFS in our country, and our national database about this rare disease is to be further exploited.

Anemia, Aplastic ; Anemia, Diamond-Blackfan ; therapy ; Bone Marrow Diseases ; Child ; Dyskeratosis Congenita ; therapy ; Fanconi Anemia ; therapy ; Fetal Blood ; Hematopoietic Stem Cell Transplantation ; Hemoglobinuria, Paroxysmal ; diagnosis ; genetics ; therapy ; Humans ; Retrospective Studies ; Siblings ; Survival Rate ; Transplantation Conditioning ; Unrelated Donors ; Vidarabine ; analogs & derivatives ; therapeutic use

OBJECTIVETo investigate the genetic instability in patients with Dyskeration congenita.

METHODSThe spontaneous chromosome instability of lymphocytes from 4 DC patients, 29 FA patients and 24 healthy volunteers was assessed with comet assay. The percent of DNA in comet head (HeadDNA%）, the percent of DNA in comet tail (TailDNA%）, tail moment (TM), olive tail moment (OTM), the comet cell percentage (CCP) were compared between groups. And the results of MMC test, PNH clones and karotype were analysed additionally. The correlation between TM, OTM, CCP and the severity degree of bone marrow failure in DC group were evaluated.

RESULTS①PNH clones and karotype abnormalities were not found in 4 DC patients. ②TM (6.77 ± 0.90), OTM（6.19 ± 0.80) and CCP [(46.00 ± 5.03) %] in DC were significantly higher than those in normal control group [0.61 ± 0.49, 0.66 ± 0.42, (5.91 ± 3.19)%, P<0.05], however, not distinguished from FA patients [7.81 ± 3.58, 6.65 ± 2.21, (56.03 ± 13.47) %, P ≥ 0.05]. The aberrant cell percent at the MMC concentration of 80 μg/L in DC group was significantly lower than that in FA group [(21.00 ± 3.16) % vs (31.97 ± 6.33)%, P=0.003]. ③The correlation between TM, OTM, CCP and the severity of bone marrow failure in DC group were not found (P>0.05).

CONCLUSIONDC patients were of significantly increased genetic instability and normal DNA repair, which was different from that in FA patients. And there was no correlation between the degree of genetic instability and the severity of bone marrow failure in DC patients presenting as aplastic anemia.

Case-Control Studies ; Chromosomal Instability ; Comet Assay ; Dyskeratosis Congenita ; genetics ; Fanconi Anemia ; genetics ; Humans ; Lymphocytes ; Pancytopenia

OBJECTIVETo investigate the effect of PARP1 inhibitor PJ34 on multi-drug resistance in a human multiple myeloma cell line and its connection with FA/BRCA pathway in DNA damage repair.

METHODSA CCK8 assay was used to measure the inhibition rate. Real-time quantitative PCR was used to detect expression changes of DNA repair genes involved in the FA/BRCA pathway. Western blotting assay was used to detect expression of key protein FANCD2 in the FA/BRCA pathway. Annexin VFITC/PI double staining flow cytometry was used to measure cell apoptosis induced by PJ34. A COMET assay was used to detect the effect of PJ34 on DNA damage repair.

RESULTSPJ34 could significantly enhance the sensitivity of RPMI8226/R cells to melphalan. The IC50 value of melphalan was dropped from 20.43 mol/L to 7.8 mol/L. PJ34 could inhibit the DNA damage repair, and the effect was related with the inhibition of FA/BRCA pathway. PJ34 and melphalan showed a synergistic effect in promoting the apoptosis of RPMI8226/R cells.

CONCLUSIONPJ34 can reverse the resistance of RPMI8226/R cells to melphalan by inhibiting the FA/BRCA pathway, which in turn can induce suppression of DNA damage repair. Therefore, PJ34 may have clinical value in overcoming the multi-drug resistance of multiple myeloma.

Antineoplastic Agents ; pharmacology ; BRCA2 Protein ; genetics ; metabolism ; Cell Line, Tumor ; Drug Resistance, Neoplasm ; Fanconi Anemia Complementation Group D2 Protein ; genetics ; metabolism ; Humans ; Multiple Myeloma ; drug therapy ; enzymology ; genetics ; metabolism ; Phenanthrenes ; pharmacology ; Poly (ADP-Ribose) Polymerase-1 ; Poly(ADP-ribose) Polymerase Inhibitors ; Poly(ADP-ribose) Polymerases ; genetics ; metabolism