Hurler's Syndrome is classified as which type of inheritance?

• A. X-linked dominant
• B. Autosomal dominant
• C. Autosomal recessive
• D. Mitochondrial

Answer: (C)

Hurler's Syndrome, also known as Mucopolysaccharidosis type I (MPS I), is indeed classified as an autosomal recessive disorder. This means that for an individual to express the syndrome, they must inherit two copies of the mutated gene, one from each parent. In the case of Hurler's Syndrome, this mutation affects the enzyme alpha-L-iduronidase, which is necessary for the breakdown of specific sugars in the body. When both copies of the gene are defective, it leads to a buildup of glycosaminoglycans (previously known as mucopolysaccharides), causing a variety of health issues, including developmental delays, skeletal problems, and heart disease.

This classification as autosomal recessive is significant because it means that the parents, who are carriers of the gene mutation, typically do not show symptoms of the disorder themselves. Therefore, understanding the inheritance pattern is essential for genetic counseling and assessing the risks for potential offspring.