Final answer:
After a baby screens positive for a CFTR gene mutation, further diagnostic tests are needed and a genetic counselor should be consulted to interpret the results and discuss the risks and management options.
Step-by-step explanation:
If a baby screens positive for a CFTR gene mutation, the next step typically involves further testing and consultation with a genetic counselor. A confirmatory diagnostic test, such as a sweat chloride test, DNA sequence analysis, or an expanded newborn screening, may be required to establish a diagnosis of cystic fibrosis. Genetic counselors play a crucial role by educating the family on the implications of the genetic test results, assessing the risk of cystic fibrosis in future offspring, and discussing options for family planning and management of the condition. It's important to note that while a positive screen indicates the presence of a CFTR mutation, it does not necessarily confirm the diagnosis of cystic fibrosis, as an individual must have two copies of the mutant gene to actually have the disease.