What manifestation is a finding that is specific to pernicious anemia?

A. Hernia causes mechanical bowel obstruction by physically trapping or compressing the intestine, preventing content passage. This aligns with the patient’s hernia, creating a structural blockage consistent with clinical findings.

B. Hypokalemia leads to functional bowel obstruction by disrupting intestinal motility through electrolyte imbalances, impairing muscle contractions without physical blockage. This matches the patient’s hypokalemia, exacerbating adynamic ileus.

C. Anesthesia from surgery causes functional bowel obstruction by slowing intestinal peristalsis, often resulting in postoperative ileus. This aligns with the patient’s recent anesthesia exposure, disrupting coordinated muscle contractions.

D. Intestinal tumor results in mechanical bowel obstruction by physically blocking or compressing the intestinal lumen, impeding content flow. The patient’s tumor aligns with this mechanism, a common cause of mechanical obstruction.

E. Pancreatitis contributes to functional bowel obstruction by causing inflammation or retroperitoneal irritation, leading to adynamic ileus without physical blockage. This matches the patient’s pancreatitis, disrupting intestinal motility.

F. Adhesions cause mechanical bowel obstruction by forming fibrous bands that kink or compress the intestine, blocking content passage. The patient’s adhesion history aligns with this, a leading cause of small bowel obstruction

Choice A reason: Autosomal dominant disorders affect both genders equally, as they are not sex-linked. Heterozygous individuals express the disorder, not just males, due to the dominant allele on an autosome. The idea of females being carriers only applies to X-linked recessive disorders, making this choice scientifically inaccurate.

Choice B reason: Autosomal dominant disorders are caused by mutations on autosomes, not the Y chromosome, which is sex-linked and primarily affects males. These disorders do not typically skip generations, as the dominant allele is expressed in every affected individual, making this choice incorrect.

Choice C reason: In autosomal dominant disorders, a single mutated allele is sufficient for expression. An affected parent (heterozygous) has one normal and one mutated allele, leading to a 50% chance of passing the mutated allele to each child, causing the disorder. This genetic inheritance pattern makes this the correct choice.

Choice D reason: In autosomal dominant disorders, there is no "carrier" state as in recessive disorders, because heterozygous individuals express the disorder. The 50% probability applies to inheriting the disorder itself, not a carrier genotype, which is a concept relevant to autosomal recessive disorders, making this choice incorrect.