Atypical cystic fibrosis: identification in the primary care setting.

OBJECTIVE To review the diagnosis of patients with atypical cystic fibrosis (CF). SOURCES OF INFORMATION A comprehensive search of MEDLINE (1950 to the third week of May 2009), MEDLINE In-Process and Other Non-Indexed Citations and Cases (1950 to the third week of May 2009), and EMBASE (1980 to the fourth week of March 2009). The Cystic Fibrosis Canada website was also reviewed and the most recent patient data registry report was consulted. MAIN MESSAGE Atypical CF is a milder form of the CF disorder, which is associated with mutations of the cystic fibrosis transmembrane receptor gene. Instead of having classic symptoms, individuals with atypical CF might only have mild dysfunction in 1 organ system and might or might not have elevated sweat chloride levels. Atypical CF is a very diverse disorder affecting different organ systems to varying degrees. The symptoms patients experience can also fluctuate over time; however, certain clinical signs and symptoms affecting the respiratory, gastrointestinal, endocrine and metabolic, and genitourinary systems should alert physicians to the possibility of CF. Patients with atypical CF often have fewer hospitalizations during childhood than those with classic CF do, and the disorder can remain undiagnosed for many years, at times into adulthood. CONCLUSION Although patients diagnosed with atypical CF have longer life expectancies than individuals with classic CF, the long-term expected outcome for many individuals with atypical CF is unknown. It is important to counsel patients about the possibility of future illness. Education about CF can help patients understand their symptoms, modify their lifestyles to optimize health, reduce the incidence of complications, and receive family planning counseling when appropriate.