What are the hypothesized modes of transmission for Diamond-Blackfan Anemia?

Diamond-Blackfan Anemia (DBA) is primarily a genetic disorder characterized by macrocytic anemia and is often diagnosed in infancy or early childhood. It has several hypothesized modes of transmission, which is why the correct answer identifies autosomal dominant inheritance, X-linked patterns, and sporadic mutations as contributing factors.

The autosomal dominant inheritance pattern suggests that, in some cases, a single copy of the mutated gene is sufficient to cause the disorder. Some individuals may inherit DBA directly from a parent who has the condition. The presence of an X-linked pattern means that there may be instances where the condition is passed through the maternal line, affecting males more significantly due to the presence of a single X chromosome.

Sporadic mutations refer to cases where DBA occurs without a clear genetic inheritance pattern, which can be attributed to new, non-hereditary mutations that arise in an individual. This can also explain instances where no family history is noted, and still, a child presents with DBA due to a random mutation.

Together, these patterns underscore the complexity of DBA's genetic basis, which involves not only inheritance but also spontaneous genetic changes. This multifaceted approach to understanding transmission is crucial for assessment, management, and genetic counseling in affected families.