Cystic Fibrosis screen positive, inconclusive diagnosis (CFSPID) to Cystic Fibrosis: Detecting disease with serial...

Area of Science:

• Pediatric Pulmonology
• Genetic Diagnosis
• Cystic Fibrosis Research

Background:

• Newborn screening identifies infants with Cystic Fibrosis Screen Positive, Inconclusive Diagnosis (CFSPID).
• CFSPID designation requires careful monitoring due to potential progression to Cystic Fibrosis (CF).

Observation:

• A case is presented of a child initially designated CFSPID.
• The child later developed recurrent respiratory symptoms and underwent CFTR functional testing.
• Diagnosis was reclassified to CF despite normal sweat chloride levels.

Findings:

• CFTR functional testing and clinical presentation are crucial for diagnosing CF in CFSPID cases.
• Normal sweat chloride levels do not exclude a CF diagnosis in all cases.
• Individual CFTR mutation phenotypes and evolving clinical findings necessitate re-evaluation.

Implications:

• This case underscores the importance of vigilant monitoring for children with CFSPID.
• It provides an approach for challenging the CFSPID designation when CF is suspected.
• Early and accurate diagnosis of CF is critical for timely intervention and management.