OBJECTIVETo study FANCA protein expression in Fanconi anemia patient's (FA) cells and explore its function.

METHODSFANCA protein expression was analyzed in 3 lymphoblast cell lines derived from 3 cases of type A FA (FA-A) patients using Western blot. Nucleus and cytoplasm localization of FANCA protein was analyzed in one case of FA-A which contained a truncated FANCA (exon 5 deletion). The FANCA mutant was constructed from the same patient and its interaction with FANCG was evaluated by mammalian two-hybrid (M2H) assay.

RESULTSFANCA protein was not detected in the 3 FA-A patients by rabbit anti-human MoAb, but a truncated FANCA protein was detected in 1 of them by mouse anti-human MoAb. The truncated FANCA could not transport from cytoplasm into nucleus. The disease-associated FANCA mutant was defective in binding to FANCG in M2H system.

CONCLUSIONSFANCA proteins are defective in the 3 FA-A patients. Disfunction of disease-associated FANCA mutant proved to be the pathogenic mutations in FANCA gene. Exon 5 of FANCA gene was involved in the interaction between FANCA and FANCG.

Cell Line ; Child ; Exons ; Fanconi Anemia ; genetics ; metabolism ; Fanconi Anemia Complementation Group A Protein ; genetics ; metabolism ; Humans ; Lymphocytes ; metabolism ; Male ; Mutation

OBJECTIVETo screen the FANCA gene mutation and explore the FANCA protein function in Fanconi anemia (FA) patients.

METHODSFANCA protein expression and its interaction with FANCF were analyzed using Western blot and immunoprecipitation in 3 cases of FA-A. Genomic DNA was used for MLPA analysis followed by sequencing.

RESULTSFANCA protein was undetectable and FANCA and FANCF protein interaction was impaired in these 3 cases of FA-A. Each case of FA-A contained biallelic pathogenic mutations in FANCA gene.

CONCLUSIONSNo functional FANCA protein was found in these 3 cases of FA-A, and intragenic deletion, frame shift and splice site mutation were the major pathogenic mutations found in FANCA gene.

Cell Line ; DNA Mutational Analysis ; Fanconi Anemia ; genetics ; metabolism ; Fanconi Anemia Complementation Group A Protein ; genetics ; metabolism ; Humans ; Mutation

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

Fanconi anemia (FA) is an autosomal or X-linked recessive disorder characterized by chromosomal instability, bone marrow failure, cancer susceptibility, and a profound sensitivity to agents that produce DNA interstrand cross-link (ICL). To date, 15 genes have been identified that, when mutated, result in FA or an FA-like syndrome. It is believed that cellular resistance to DNA interstrand cross-linking agents requires all 15 FA or FA-like proteins. Here, we review our current understanding of how these FA proteins participate in ICL repair and discuss the molecular mechanisms that regulate the FA pathway to maintain genome stability.
DNA Damage ; DNA Repair ; Exodeoxyribonucleases ; genetics ; metabolism ; Fanconi Anemia ; genetics ; metabolism ; pathology ; Fanconi Anemia Complementation Group N Protein ; Fanconi Anemia Complementation Group Proteins ; genetics ; metabolism ; Humans ; Nuclear Proteins ; genetics ; metabolism ; Recombinases ; genetics ; metabolism ; Tumor Suppressor Proteins ; genetics ; metabolism ; Ubiquitination

Fanconi anemia (FA) is a rare genetic disorder affecting multiple body systems. Genetic testing, including prenatal testing, is a prerequisite for the diagnosis of many clinical conditions. However, genetic testing is complicated for FA because there are often many genes that are associated with its development, and large deletions, duplications, or sequence variations are frequently found in some of these genes. This study describes successful genetic testing for molecular diagnosis, and subsequent prenatal diagnosis, of FA in a patient and his family in Korea. We analyzed all exons and flanking regions of the FANCA, FANCC, and FANCG genes for mutation identification and subsequent prenatal diagnosis. Multiplex ligation-dependent probe amplification analysis was performed to detect large deletions or duplications in the FANCA gene. Molecular analysis revealed two mutations in the FANCA gene: a frameshift mutation c.2546delC and a novel splice-site mutation c.3627-1G>A. The FANCA mutations were separately inherited from each parent, c.2546delC was derived from the father, whereas c.3627-1G>A originated from the mother. The amniotic fluid cells were c.3627-1G>A heterozygotes, suggesting that the fetus was unaffected. This is the first report of genetic testing that was successfully applied to molecular diagnosis of a patient and subsequent prenatal diagnosis of FA in a family in Korea.
Base Sequence ; Child, Preschool ; Exons ; Fanconi Anemia/*diagnosis/genetics ; Fanconi Anemia Complementation Group A Protein/genetics ; Fanconi Anemia Complementation Group C Protein/genetics ; Fanconi Anemia Complementation Group G Protein/genetics ; Female ; Frameshift Mutation ; Genetic Testing ; Heterozygote ; Humans ; Karyotyping ; Male ; Pregnancy ; Prenatal Diagnosis ; RNA Splice Sites ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA

Fanconi anaemia (FA) is an autosomal recessive inherited disorder caused by defects in hematopoietic stem cells. The clinical manifestations of FA are diverse and complicated. FA cells display high hypersensitivity to agents which produce interstrand DNA cross-links such as mitomycin C (MMC) or diepoxybutane (DEB). At least eight complementation groups with defects in eight genes (FANCA, FANCB, FANCC, FANCD(1), FANCD(2), FANCE, FANCF and FANCG) have been identified by gene analysis. Six genes (corresponding to subtypes A, C, D(2), E, F and G) have been coloned, and the encoded FA proteins interact in a common cellular pathway - "FA Pathway", through which modulate DNA repair. The progress of research on FA molecular mechanism provides gene therapy of FA with theory basis. FA cells transduced with the use of retrovirus carring the normal FA gene cDNA manifestate phenotypic correction of hypersensitivity to DNA cross-linking agents, such as MMC. In this review the clinical manifestations and gene composition of FA, and the functions of encoded FA proteins were summarized. The hematopoietic stem cell transplantation and gene therapy for FA patients were discussed.
Cell Cycle Proteins ; DNA-Binding Proteins ; Fanconi Anemia ; genetics ; metabolism ; therapy ; Fanconi Anemia Complementation Group C Protein ; Fanconi Anemia Complementation Group D2 Protein ; Fanconi Anemia Complementation Group Proteins ; Genetic Therapy ; Hematopoietic Stem Cell Transplantation ; Humans ; Mutation ; Nuclear Proteins ; genetics ; Proteins ; analysis ; genetics

BACKGROUNDFanconi anemia is a severe congenital disorder associated with mutations in a cluster of genes responsible for DNA repair. Arriving at an accurate and timely diagnosis can be difficult in cases of Fanconi anemia with atypical clinical features. It is very important to increase the rate of accurate diagnosis for such cases in a clinical setting. The purpose of this study is to explore the clinical diagnosis of Fanconi anemia in children with atypical clinical features.

METHODSSix cases of Fanconi anemia with atypical clinical features were enrolled in the study, and their clinical features were recorded, their FANCA gene transcription was assessed by RT-PCR, and FANCA mutations and the ubiquitination of FANCD2 protein were analyzed using DNA sequencing and western blotting respectively.

RESULTSAll six cases showed atypical clinical features including no apparent deformities, lack of response to immune therapy, and progressively increasing bone marrow failure. They also have significantly increased fetal hemoglobin, negative mitomycin-induced fracture test results, and carry a FANCA gene missense mutation. Single protein ubiquitination of FANCD2 was not observed in those patients.

CONCLUSIONThe combination of clinical features, FANCA pathogenic gene mutation genotype and the absence of FANCD2 protein ubiquitination are helpful in the accurate and timely diagnosis of Fanconi anemia in children.

Child ; Child, Preschool ; Fanconi Anemia ; diagnosis ; genetics ; metabolism ; Fanconi Anemia Complementation Group D2 Protein ; genetics ; metabolism ; Female ; Humans ; Male ; Mutation ; Ubiquitination

This study was purposed to investigate the relationship between expression of the FANCG gene and adult sporadic acute myeloid leukemia (AML), real-time PCR with SYBR Green I technique was used for detecting FANCG gene expression level in bone marrow mononuclear cells of 54 newly diagnosed AML patients, 46 AML patients in complete remission (CR) and 36 control samples. β-actin gene was used as internal reference. Relative changes of FANCG gene expression level were detected by 2(-ΔΔCT) method in newly diagnosed AML patients and control samples, in newly diagnosed AML and patient in CR, as well as in AML patients in CR and control samples. The results showed that the relative expression level of FANCG mRNA was 0.56 ± 0.27 in newly diagnosed group, 0.75 ± 0.54 in AML CR group, and 0.85 ± 0.45 in control group. The expression level of FANCG mRNA in newly diagnosed group was significantly lower than that in control and AML CR groups (P < 0.05). There was no statistically significant deference in comparison of AML CR group with the control group (P > 0.05). It is concluded that the expression of FANCG gene decrease in the newly diagnosed AML patients. There is no significant difference between AML CR group and control group, which indicated that FANCG gene may be related with the onset and the prognosis of AML, and may provide a clinical value for evaluating effect of chemotherapy.
Adult ; Fanconi Anemia Complementation Group G Protein ; genetics ; Female ; Humans ; Leukemia, Myeloid, Acute ; genetics ; pathology ; Male ; Middle Aged ; Prognosis ; RNA, Messenger ; genetics ; Real-Time Polymerase Chain Reaction

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 investigate the possible relationship between defects in the FA/BRCA pathway of genomic stability and potential pathogenesis of T and B cell lymphoma.

METHODSNineteen cell lines derived from diverse subtypes of lymphoma for possible FA pathway defects were screened.

RESULTSNo defect in FANCD2 ubiquitination was observed. However, the FANCN protein was absent in cell lines HT and Sudhl4. This absence was correlated with enhanced MMC-induced G2 arrest, growth inhibition and high chromosomal breakage rate in both cell lines. In addition, in exon-5a of FANCN gene, a mutation of c.1769 C>T, p. A590V was found in cell line HT, but not in cell line Sudhl4.

CONCLUSIONThis mutation may be the reason causing the absence of the FANCN protein expression or making the protein unstable and losing its function.

Animals ; Antibiotics, Antineoplastic ; pharmacology ; BRCA2 Protein ; metabolism ; Base Sequence ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Chromosome Breakage ; drug effects ; Fanconi Anemia ; metabolism ; Fanconi Anemia Complementation Group D2 Protein ; metabolism ; Fanconi Anemia Complementation Group N Protein ; Gene Expression Regulation, Neoplastic ; Genomic Instability ; Humans ; Lymphoma ; genetics ; pathology ; Mitomycin ; pharmacology ; Molecular Sequence Data ; Mutation ; Nuclear Proteins ; chemistry ; deficiency ; genetics ; metabolism ; Protein Stability ; Sequence Analysis, DNA ; Signal Transduction ; Tumor Suppressor Proteins ; chemistry ; deficiency ; genetics ; metabolism