Cystic fibrosis in a Hispanic adolescent.

We describe the presentation of a Hispanic adolescent with chronic respiratory symptoms and poor growth that led to a diagnosis of cystic fibrosis (CF) based on an indeterminate sweat chloride result and DNA sequence analysis that revealed a single new frameshift mutation, Nt3878insATCAG, which results in a premature stop codon in exon 20 of the CFTR gene. This case, highlighted by the identification of a deleterious, disease-causing mutation, illustrates the importance of maintaining both a high clinical suspicion for CF and low threshold for obtaining genetic testing in a non-Caucasian Hispanic adolescent with a characteristic clinical presentation.