FANCA Gene in Pakistani Fanconi Anemia Patients: Screening of Mutations in Exon 28 and Exon 29

Objective: This kind of study was conducted first time in Pakistan. Its objective was to ascertain the associated clinical features and analyze the FANCA exon 28 and exon 29 mutations in Pakistani Fanconi anemia (FA) patients. Methods: A total of 38 patients with Fanconi anemia were recruited presenting in the Armed forces institute of pathology (AFIP) Rawalpindi Pakistan. They were enrolled in this study on the basis of comprehensive clinical evaluation and positive Diepoxybutane (DEB)/Mitomycin C Chromosomal breakage test. Genomic DNA was extracted from peripheral blood of patients and age and gender-matched controls. Mutation analysis of FANCA gene was done by conventional Polymerase chain reaction (PCR) and DNA sequencing. Various online tools and software were used for analysis of the obtained data and identification of the sequence alterations in FANCA gene in exon 28 and exon 29 of FA patients. Results and Discussion: The current study on screening of FANCA mutational analysis in exon 28 and exon 29 revealed four novel mutations. These include three missense variants (p.F876L, p.L883H, and p.K921I) in exon 28 and a novel homozygous frameshift variant (p.S947FfsX950) in exon 29. In addition two new intronic variants were also found in this set of patients. Conclusion: The sequence variants identified in this study in 10 (26.31%) FA patients in two out of forty-three FANCA gene exons (i.e., exon 28 and exon 29) strongly emphasize the importance of large-scale molecular studies on FANCA gene in Pakistani population.

Investigation of FANCA gene in Fanconi anaemia patients in Iran.

Background & objectives: Fanconi anaemia (FA) is a syndrome with a predisposition to bone marrow failure, congenital anomalies and malignancies. It is characterized by cellular hypersensitivity to cross-linking agents such as mitomycin C (MMC). In the present study, a new approach was selected to investigate FANCA (Fanconi anaemia complementation group A) gene in patients clinically diagnosed with cellular hypersensitivity to DNA cross-linking agent MMC. Methods: Chromosomal breakage analysis was performed to prove the diagnosis of Fanconi anaemia in 318 families. Of these, 70 families had a positive result. Forty families agreed to molecular genetic testing. In total, there were 27 patients with unknown complementary types. Genomic DNA was extracted and total RNA was isolated from fresh whole blood of the patients. The first-strand cDNA was synthesized and the cDNA of each patient was then tested with 21 pairs of overlapping primers. High resolution melting curve analysis was used to screen FANCA, and LinReg software version 1.7 was utilized for analysis of expression. Results: In total, six sequence alterations were identified, which included two stop codons, two frames-shift mutations, one large deletion and one amino acid exchange. FANCA expression was downregulated in patients who had sequence alterations. Interpretation & conclusions: The results of the present study show that high resolution melting (HRM) curve analysis may be useful in the detection of sequence alteration. It is simpler and more cost-effective than the multiplex ligation-dependent probe amplification (MLPA) procedure.

A Case Report of Fanconi Anemia Diagnosed by Genetic Testing Followed by Prenatal Diagnosis

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.

Overexpression of the Fanconi Anemia A Gene in Hela and MCF10A Cells

BACKGROUND: Fanconi Anemia (FA) is an autosomal recessive inherited disease, which is characterized by developmental abnormalities, progressive bone marrow failure and a predisposition to cancer. The phenotypes of FA cells show extreme sensitivities towards oxygen and DNA cross linking agents, such as diepoxybutane and mitomycin C (MMC). METHODS: In the current study, retroviruses expressing the FANCA gene were prepared to create the stable cell lines, Hela (cervical carcinoma) and MCF10A (breast). The expression of FANCA protein in the Hela and MCF10A stable cells, following puromycin selection, was checked using Western blot. The difference in the cell growth between the parent and FANCA expressing cells following MMC treatment was checked using the MTT assay. RESULTS: The expression of exogenous FANCA protein in the Hela and MCF10A stable cells was observed using Western blot. The MCF10A cells expressing exogenous FANCA were resistant to MMC concentrations with the range 0.01~1 micrometer compared with the MCF10 parent cells. However, at an MMC concentration of 10 micrometer, there was no difference in the susceptibility between the parent and FANCA expressing MCF10 cells. The Hela cells expressing FANCA showed no resistance at any MMC concentration (0.01~10 micrometer). CONCLUSION: FANCA protein is an important factor for resistance to the cross linking agent, MMC, in MCF10A breast cells, but not in Hela cervical carcinoma cells.