Fanconi’s anemia is a –
**Core Concept**
Fanconi's anemia is a rare genetic disorder characterized by congenital abnormalities, bone marrow failure, and a predisposition to malignancies. It is caused by mutations in the Fanconi anemia complementation group (FANC) genes, which play a crucial role in the repair of interstrand DNA crosslinks.
**Why the Correct Answer is Right**
Fanconi's anemia is a result of defects in the Fanconi anemia pathway, a DNA repair mechanism that maintains genomic stability. The FANC genes, including FANCA, FANCC, and FANCG, are involved in the recognition and repair of DNA interstrand crosslinks, which are induced by certain chemicals and radiation. The inability to repair these crosslinks leads to chromosomal instability, bone marrow failure, and an increased risk of cancer.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Fanconi's anemia is not primarily associated with mutations in the p53 gene, which is involved in a different DNA repair pathway.
**Option B:** This option is incorrect because Fanconi's anemia is not characterized by a deficiency in DNA replication, but rather by defects in DNA repair.
**Option C:** This option is incorrect because Fanconi's anemia is not a result of a viral infection, but rather a genetic disorder caused by mutations in the FANC genes.
**Clinical Pearl / High-Yield Fact**
Fanconi's anemia is often associated with physical anomalies, such as short stature, microcephaly, and abnormalities of the skin, hair, and skeletal system. Patients with Fanconi's anemia also have an increased risk of developing cancers, particularly acute myeloid leukemia and squamous cell carcinoma.
**Correct Answer: D.**