Sweat Chloride Testing

A 5-year-old girl with a family history of cystic fibrosis presented with constipation, poor weight gain, and a BMI below the third percentile. Three sweat chloride tests were indeterminate, aCFTR analysis panel was negative, and whole-genome sequence analysis revealed 1 cystic fibrosis –causing mutation. What would you do next?
Source: JAMA - Journal of the American Medical Association - Category: General Medicine Source Type: research