Abstract
Fanconi anemia (FA) is a rare inherited disease caused by mutations in genes that are primarily involved in DNA damage response or repair. The disease is often characterized by congenital malformations, progressive bone marrow failure, abnormal skin pigmentation patterns and susceptibility to cancer. The present study describes a pair of 4-year-old male twins, both of whom had been suffering from upper respiratory tract infections for >2 years. There was no indication of discomfort including fever, coughing, bleeding or fatigue from either child when the upper respiratory tract infection disappeared. Physical examination of the twins did not reveal anything significant, and no external anomalies were observed. In order to obtain additional diagnostic evidence, next-generation gene sequencing, chromosome breakage analysis and comet assays were performed. The results revealed double heterozygous mutations in the Fanconi Anemia Complementation Group D2 gene of the twins, therefore providing a conclusive diagnosis of FA. The case highlights how difficulties in clinical diagnosis may be overcome by including genetic screening tests into the range of diagnostic tests, which may also reveal unexpected results.