Question

Which of the following is a genetic disorder that predisposes the patient to repeated lung infections?

1) Cystic fibrosis
2) Down syndrome
3) Huntington's disease
4) Sickle cell anemia

Answer 1

Cystic fibrosis is a genetic disorder that leads to repeated lung infections and is inherited as an autosomal recessive trait. It is caused by a mutation in the CFTR gene resulting in thick mucus in the lungs and other organs.

Step-by-step explanation:

Cystic Fibrosis as a Genetic Disorder

The genetic disorder that predisposes patients to repeated lung infections is cystic fibrosis (CF). Cystic fibrosis is a noninfectious disease inherited as an autosomal recessive trait caused by a mutation in the CFTR gene. The result of this mutation is the production of thick and sticky mucus that can obstruct the mucus-secreting organs, notably the lungs and intestines. This leads to recurrent respiratory infections and impairs nutrient absorption due to malabsorption issues. Despite the severe symptoms, medical advancements have extended the life expectancy of CF patients into middle adulthood.

Approximately 30,000 people in the United States are affected by cystic fibrosis, and a child born to two carriers of the CF gene has a 25% chance of inheriting the disease. This follows the 3:1 dominant:recessive ratio established by Mendelian inheritance patterns.