Certified Ophthalmic Medical Technologist (COMT) Practice Exam

The inability to perceive colors correctly is usually inherited in what manner?

1. Father to daughter (Y-linked inheritance pattern)

2. Mother to male child (X-linked inheritance pattern)

3. Autosomal dominant inheritance

4. Mitochondrial inheritance

The correct answer is: Mother to male child (X-linked inheritance pattern)

The correct answer reflects the common pattern of inheritance for color vision deficiencies, often seen in conditions like color blindness. These conditions are typically linked to genes located on the X chromosome. Males have one X and one Y chromosome, so any mutation that causes color vision deficiency will manifest in males, as they do not have a second X chromosome that could potentially mask the effect of the faulty gene. In contrast, females have two X chromosomes, so they would need two copies of the mutated gene to express the same color vision deficiency. Thus, a mother, who may be a carrier of the trait (having one affected X and one normal X), can pass on the mutated X chromosome to her sons, resulting in the sons being affected by color vision deficiencies. This means that the primary inheritance pattern seen is indeed from mother to male offspring, highlighting the X-linked inheritance characteristic of these conditions.