Pediatric and Adult Recommendations Vary for Sibling Testing in Cystic Fibrosis

Kimberly L. Brown, Patrick A. Flume

Four to 5 % of cystic fibrosis (CF) patients are diagnosed as adults and often have subtler symptoms. Their siblings are at genetic risk to also have a subtler disease state. Diagnostic testing is recommended for siblings of newly diagnosed infants, but recommendations are less clear for later diagnoses. This study explored sibling testing recommendations in pediatric and adult practice using a survey that was emailed to CF clinicians. There were 58 respondents. Results revealed that 82.5% of pediatric and 36.4% of adult care respondents reported always recommending diagnostic testing for siblings of a newly diagnosed patient. In adult care, another 33.3% reported recommending diagnostic testing if the sibling has symptoms. In pediatric care, whether the sibling had newborn screening was most influential. Most pediatric respondents prefer the sweat chloride test, while 40% in adult practice prefer familial mutation analysis. Perceived barriers included cost, insurance coverage and logistical concerns in both settings, parental emotional state in pediatrics, and concern making recommendations for someone who is not the patient in adult care. Genetic counselors may be able to meet familial needs in CF care, including sibling testing. Many newly diagnosed patients/families do not see a genetic counselor, especially in adult care. These data reveal opportunities for practice guidelines and standardization.