Certified Pediatric Hematology Oncology Nurse (CPHON) Practice Exam 2025 - Free CPHON Practice Questions and Study Guide

The observation that females with Diamond-Blackfan Anemia (DBA) experience more severe symptoms is accurately attributed to the skewed X chromosome inactivation pattern. In females, since they have two X chromosomes, one of these chromosomes is randomly inactivated in each cell. However, in situations where there is a genetic disease linked to the X chromosome, skewing of this inactivation can lead to a variable expression of symptoms depending on which X chromosome is predominantly active in the cells.

In the case of DBA, if the X chromosome that carries the mutation associated with the disorder is the one that remains active more frequently due to skewing, it can result in more pronounced symptoms. This biological phenomenon helps to explain why females may experience more severe manifestations of DBA compared to males, who have only one X chromosome and therefore do not have this variability in expression.

Other statements do not accurately capture the relationship between gender and symptom severity in DBA. Specifically, stating that females have less severe symptoms contradicts the established understanding of the condition. The idea that females show no difference fails to acknowledge the documented severity discrepancy, and the assertion that DBA affects females exclusively is incorrect, as both genders can be affected by this anemia.