A couple seeks counseling about the risk of their child developing a recessive disorder. The woman is affected and upon further testing it is determined that the man is a carrier. Which of the following is true?

Choice A reason: Severe hypotension is associated with prerenal acute kidney injury, not postrenal. Prerenal acute kidney injury results from decreased blood flow to the kidneys due to conditions like severe hypotension, leading to reduced kidney perfusion.

Choice B reason: Acute tubular necrosis (ATN) is a form of intrinsic or intrarenal acute kidney injury, not postrenal. ATN is typically caused by prolonged ischemia or exposure to nephrotoxic agents, which directly damage the kidney tubules.

Choice C reason: Postrenal acute kidney injury is caused by an obstruction in the urinary tract that prevents urine from leaving the kidneys, leading to increased pressure and kidney damage. Bilateral kidney stones partially blocking the flow of urine can cause such an obstruction, leading to postrenal acute kidney injury.

Choice D reason: Glomerulonephritis is a type of intrinsic or intrarenal acute kidney injury, not postrenal. It involves inflammation and damage to the glomeruli, the filtering units within the kidneys, and is not typically caused by an obstruction in the urinary tract.

Choice A reason: Autosomal-recessive disorders affect both males and females equally because the gene in question is located on one of the autosomes (non-sex chromosomes). Each individual has two copies of each autosomal gene, one from each parent. An autosomal-recessive disorder manifests when an individual inherits two copies of a mutant gene, one from each parent. Therefore, gender does not influence the likelihood of being affected.

Choice B reason: Autosomal-dominant disorders also affect both males and females equally. These disorders occur when a single copy of a mutant gene on an autosome is sufficient to cause the disorder. Since autosomes are present in both males and females equally, the likelihood of inheriting an autosomal-dominant disorder is not influenced by gender.

Choice C reason: Chromosomal nondisjunction refers to errors in cell division that result in an abnormal number of chromosomes. While some conditions resulting from chromosomal nondisjunction can show gender bias (such as Turner syndrome affecting females and Klinefelter syndrome affecting males), it is not accurate to say that males are generally more likely than females to be affected by chromosomal nondisjunction.

Choice D reason: X-linked (sex-linked) disorders are more likely to affect males than females because the gene causing the disorder is located on the X chromosome. Males have one X and one Y chromosome (XY), while females have two X chromosomes (XX). If a male inherits a mutant gene on the X chromosome, he will express the disorder because he does not have a second X chromosome to mask the effect. In contrast, females would need two copies of the mutant gene (one on each X chromosome) to express the disorder, making it less likely for them to be affected.