Final answer:
X-linked recessive disorders, such as Lesch-Nyhan syndrome, are genetic conditions passed down through the X chromosome and primarily affect males. Lesch-Nyhan syndrome is caused by a deficiency of the HGPRT enzyme, leading to severe symptoms like mental weakness and self-harm. Other X-linked disorders include color blindness, hemophilia, and muscular dystrophy, which are more commonly symptomatic in males.
Step-by-step explanation:
X-Linked Recessive Disorders
X-linked recessive disorders are conditions that are passed down through the X chromosome. Males, having one X and one Y chromosome, are often affected by these disorders because they have only one copy of the X chromosome. An example of such a disorder is Lesch-Nyhan syndrome, which is caused by a deficiency in the enzyme Hypoxanthine Guanine Phosphoribosyltransferase (HGPRT). This enzyme deficiency leads to the inability to salvage hypoxanthine and guanine, resulting in their breakdown into uric acid. Lesch-Nyhan syndrome is characterized by mental weakness and a tendency to self-injure, with the affected individuals typically being male.
X-linked recessive inheritance means that females can be carriers of the disorder without showing symptoms because they have a second, normal X chromosome to compensate for the faulty gene. Females with one copy of the recessive allele are carriers and typically do not exhibit severe symptoms. However, their male offspring have a 50% chance of inheriting the disorder.
Other examples of X-linked recessive disorders include red-green color blindness, hemophilia, and some forms of muscular dystrophy. These disorders are more prevalent in males due to their single X chromosome. G6PD deficiency, for example, can cause prolonged neonatal jaundice and is more commonly symptomatic in males, although females can be mildly affected or be carriers.