Which of the following is not a characteristic of Fanconi anaemia –
**Core Concept**
Fanconi anaemia is a rare genetic disorder characterized by congenital abnormalities, bone marrow failure, and an increased risk of malignancies. It is caused by mutations in the Fanconi anaemia complementation group genes, leading to impaired DNA repair mechanisms and genomic instability.
**Why the Correct Answer is Right**
Hematologic abnormalities in infancy are not a characteristic of Fanconi anaemia. In fact, the onset of hematologic manifestations typically occurs later in childhood or adolescence. The disorder is often associated with congenital abnormalities, such as skeletal anomalies, and an increased risk of malignancies. The correct answer is incorrect because it implies that hematologic abnormalities are present from infancy, which is not a defining feature of Fanconi anaemia.
**Why Each Wrong Option is Incorrect**
**Option B:** Pancytopenia is a characteristic of Fanconi anaemia, which results from bone marrow failure and impaired DNA repair mechanisms. Patients often present with cytopenias, including anemia, neutropenia, and thrombocytopenia.
**Option C:** Skeletal anomalies are a common feature of Fanconi anaemia, occurring in approximately 30% of patients. These anomalies can include radial aplasia, thumb abnormalities, and short stature.
**Option D:** Chromosome fragility is a hallmark of Fanconi anaemia, resulting from impaired DNA repair mechanisms. Patients often exhibit increased chromosomal breakage, particularly during the G2 phase of the cell cycle.
**Clinical Pearl / High-Yield Fact**
Fanconi anaemia is a rare genetic disorder with a high risk of malignancies, particularly acute myeloid leukemia and squamous cell carcinomas. Patients should be counseled on the risks of cancer and encouraged to participate in surveillance programs.
**✓ Correct Answer: A. Hematologic abnormalities in infancy**