PB1862 WHOLE EXOME SEQUENCING REVEALS XRCC2 MUTATION CAUSING FANCONI ANEMIA

Background: The XRCC2 gene is a member of the RAD51 gene family, which encode proteins involved in homologous recombination repair of DNA damage. The XRCC2 gene acts late in the Fanconi anemia (FA)‐BRCA pathway of DNA repair. Fanconi anemia (FA) is a group of inherited disorder characterized by bone marrow failure, pancytopenia with multiple craniofacial and skeletal involvement. Aims: 1‐To delinate the XRCC2 gene mutation,how it will present,and it is association with Fanocni anemia. 2‐To show the importance of extensive genetic testing in a high consanguinous population, where autosomal recessive disorders are common. Methods: We are reporting here an extremely rare gene, detected by Whole exome sequence(WES) for a 3 years old Saudi girl born at Prince Sultan Medical Military City, with multiple congenital anomalies, bilateral hypoplastic thumb, cafe au lait spots, strabismus, abnormal limb morphology, dysmorphic facial features, short stature. Results: Patients had chromosomal breakage study of 100%. Her WES reveled a rare XRCC2 gene, c.643C>T p.(Arg215∗). which creates a premature stop codon. Summary/Conclusion: So far the detected variant is the second variant that was reported in the XRRC2 gene and has been associated with the Fanconi anemia of complementation group U (FANCU, OMIM: 617247). It was reported in a Saudi family on 2012. The importance of this communication is to emphasize on the open approach when dealing with a disease with wide possible genes like in FA. Moreover, to consider XRRC2 gene, especially in a Saudi population with high consanguinity and calls for further investigation of the potential contribution of XRCC2 mutations to the overall mutational load of FA.