Impact of IVS8-(TG)m(T)n on IRT and sweat chloride levels in newborns identified by California CF newborn screening

We examined the relation between the number of (TG) repeats at the (IVS8)-(TG)m(T)5 locus of the CFTR gene with neonatal serum immunoreactive trypsinogen (IRT) and sweat chloride (SC) concentrations in hypertrypsinogenemic infants with genotype ΔF508-9T/5T identified by California cystic fibrosis newborn screening. SC and IRT distributions increased with increasing (TG) repeats.