What type of inheritance pattern does Hurler syndrome follow?

What type of inheritance pattern does Hurler syndrome follow?

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

Answer: (B)

Hurler syndrome, also known as mucopolysaccharidosis type I (MPS I), follows an autosomal recessive inheritance pattern. This means that the disorder occurs when an individual inherits two copies of the mutated gene responsible for the condition, one from each parent. In the case of Hurler syndrome, the gene involved is the IDUA gene, which is necessary for producing an enzyme (alpha-L-iduronidase) that helps break down glycosaminoglycans. When both parents are carriers of the mutated gene, there is a 25% chance with each pregnancy for their child to inherit both mutations and thus manifest the symptoms of Hurler syndrome. This pattern is characteristic of many lysosomal storage diseases, which tend to follow autosomal recessive inheritance due to the nature of enzymatic deficiencies required for metabolism. Understanding the inheritance pattern is crucial for genetic counseling, as it helps in assessing risks for future offspring and provides insights into family planning for couples who may be carriers of the disorder.

Hurler syndrome, also known as mucopolysaccharidosis type I (MPS I), follows an autosomal recessive inheritance pattern. This means that the disorder occurs when an individual inherits two copies of the mutated gene responsible for the condition, one from each parent. In the case of Hurler syndrome, the gene involved is the IDUA gene, which is necessary for producing an enzyme (alpha-L-iduronidase) that helps break down glycosaminoglycans.

When both parents are carriers of the mutated gene, there is a 25% chance with each pregnancy for their child to inherit both mutations and thus manifest the symptoms of Hurler syndrome. This pattern is characteristic of many lysosomal storage diseases, which tend to follow autosomal recessive inheritance due to the nature of enzymatic deficiencies required for metabolism.

Understanding the inheritance pattern is crucial for genetic counseling, as it helps in assessing risks for future offspring and provides insights into family planning for couples who may be carriers of the disorder.