Phenotypic Characterization of the c.1679+1643G>T (1811+1643G>T) Mutation in Hispanic Cystic Fibrosis Patients.

Cystic fibrosis (CF) is the most common fatal genetic diseases in the United States in Caucasians. More than 2000 genetic mutations have been described and CF is now known to affect other races. The incidence of CF in individuals of Hispanic descent is estimated to be 1:9200. An uncommon mutation, 1811+1643G>T, was recently reported. We report four patients with the 1811+1643G>T mutation (homozygous or heterozygous) and describe their clinical features and compare them to the remainder of our Hispanic cohort group. The homozygous patients had a more severe phenotype compared to the Hispanic cohort in the following areas: their pancreatic status, forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), chronic Pseudomonas aeruginosa (PA) colonization, pulmonary exacerbations requiring oral and intravenous antibiotics, and hospitalization rate. These preliminary findings suggest that future studies investigating the clinical trajectory with a larger cohort of patients homozygous for the 1811+1643G>T mutation are needed.