Whole-exome sequencing identifies FANC heterozygous germline mutation as an adverse factor for immunosuppressive therapy in Chinese aplastic anemia patients aged 40 or younger: a single-center retrospective study.

Acquired aplastic anemia (AA) is a bone marrow failure disorder characterized by pancytopenia, and immunosuppressive therapy (IST) is the optional first-line management. Several studies identified the influencing factors on IST response; however, there are still a considerable number of patients suffering from poor prognoses. In this study, we enrolled 61 AA patients aged ≤ 40 years old, and whole-exome sequencing (WES) found unexpected high FANC heterozygous germline mutations (28/61, 45.9%). Patients with FANC mutations have a significantly lower absolute reticulocyte count and CD34+ % in the bone marrow and also lower 3-, 6-, and 9-month IST response than that without mutation, which were 0% vs. 25% (P = 0.017), 26.3% vs. 42.1% (P = 0.495), and 29.4% vs. 72.2% (P = 0.011), especially in anti-thymocyte globulin combined with the cyclosporin A (ATG + CsA) group, which were 0% vs.33.4% (P = 0.143), 25% vs.83.3% (P = 0.103), and 25% vs. 100% (P = 0.003), respectively. The event-free survival in the FANCwt group was also better than that in the FANCmut group (P = 0.016) and also showed in patients who received ATG + CsA treatment (P = 0.045). In addition, all the adverse effects of FANC germline mutation were not significant in stem cell-transplanted group. Our result indicated that the WES-based detection of FANC heterozygous germline mutations may have a great meaning in predicting IST response of acquired AA. This study was registered at chictr.org.cn (# ChiCTR2100054992).