In this study, we hypothesised that immunoreactive trypsinogen (IRT) levels, used in NBS as a marker of pancreatic disease and function, may reflect the degree of CFTR dysfunction in each individual and therefore would help to identify those with CRMS/CSPID who are later at risk for meeting the criteria of CF.
Some screened newborns are classified as "CF Screening Positive, Inconclusive Diagnosis", or "CFTR-related metabolic syndrome" when the diagnosis can neither be confirmed nor excluded.
Retrospective cohort study comparing phenotypes of California CF newborn screen-positive children (followed 2-8 years) who had two CF-causing mutations (diagnosed as CF) with those who had one mutation from a panel of 40 CF-causing mutations (CF40mut) and one (IVS8)-(TG)11, 12, or 13-5T mutation detected by sequencing (diagnosed as CFTR-related metabolic syndrome [cRMS]).
Diagnosis of cystic fibrosis in the kindred of an infant with CFTR-related metabolic syndrome: importance of follow-up that includes monitoring sweat chloride concentrations over time.
Ten novel variants (c.2554_2555insT, p.F1107L, c.-152G>C, p.L323P, p.L32M, c.2883_2886dupGTCA, c.2349_2350insT, p.K114del, c.-602A>T, and c.2822delT) were associated with a CF phenotype (42% of participants were diagnosed at 4 to 25 months of age), whereas 26 were associated with CFTR-related metabolic syndrome to date.
Cystic Fibrosis Foundation practice guidelines for the management of infants with cystic fibrosis transmembrane conductance regulator-related metabolic syndrome during the first two years of life and beyond.