Cystic Fibrosis Foundation Practice Guidelines for the Management of Infants with CFTR-Related Metabolic Syndrome during the First Two Years of Life and Beyond

摘要

Through early detection, newborn screening (NBS) for cystic fibrosis (CF) offers the opportunity for early intervention and improved outcomes. NBS programs screen for hypertrypsinogenemia and most also identify mutations in the CF transmembrane conductance regulator (CFTR) gene. Individuals identified by NBS are diagnosed with CF if they have an elevated sweat chloride or if they have inherited two disease-causing mutations in the CFTR gene. Mutations in the CFTR gene can cause CF, but not all CFTR mutations are disease-causing. The term CFTR-related metabolic syndrome (CRMS) is proposed to describe infants with hypertrypsinogenemia on NBS who have normal or intermediate sweat chloride values and 2 CFTR mutations, including at least one that is not known to cause CF, and thus do not meet CF Foundation guidelines for the diagnosis of CF. Individuals with one CF-causing mutation, no mutation on the other allele and an intermediate sweat chloride are presumed to be CF carriers. With what is now near-universal CF NBS in the United States, an increasing number of infants with CRMS are being identified. Given our inadequate knowledge of the natural history of CRMS, standards for diagnosis, monitoring and treatment are absent. This document aims to help guide the monitoring and care of individuals with CRMS while our knowledge base on appropriate management evolves.