Which human genetic element is correlated with a disease?

• A. Normal gene
• B. Mutant gene
• C. Environmental gene
• D. Control gene

Answer: (B)

The presence of a mutant gene is often directly correlated with various diseases in humans. These mutant genes, which can arise from mutations such as point mutations, insertions, deletions, or duplications, can lead to the production of malfunctioning proteins or the loss of functional proteins altogether. This dysfunctional protein activity can disrupt normal cellular processes, paving the way for the development of genetic disorders.

For instance, certain mutations in the BRCA1 and BRCA2 genes are well-documented as risk factors for breast and ovarian cancer. Similarly, mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene lead to cystic fibrosis. These examples illustrate how specific genetic mutations can be directly tied to the onset and progression of diseases, reinforcing the connection between mutant genes and hereditary conditions. In contrast, normal genes, environmental genes, or control genes do not exhibit this same direct correlation with disease states.