Autosomal Recessive Disease Identification

An autosomal recessive disease requires an individual to inherit two copies of a mutated gene, one from each parent, located on an autosome (a non-sex chromosome). Having only one mutated copy makes the individual a carrier.

Disease Inheritance Patterns

Let's examine the inheritance pattern for each condition:

• Cystic fibrosis: This condition is caused by mutations in the CFTR gene and follows an autosomal recessive pattern. Affected individuals have two mutated copies of the gene.
• Neurofibromatosis: This is typically an autosomal dominant disorder, meaning only one copy of the mutated gene is sufficient to cause the condition.
• Retinitis pigmentosa: This condition has varied inheritance patterns. While it *can* be autosomal recessive, it also occurs as autosomal dominant and X-linked forms.
• Vitamin D resistant rickets: The most common form, X-linked hypophosphatemia, is inherited in an X-linked dominant pattern.

Conclusion on Genetic Disorders

Based on the typical inheritance patterns, Cystic fibrosis is the classic example of an autosomal recessive disease among the choices provided.