Delayed Diagnosis of Cystic Fibrosis Harms Infants, Especially Those of Color

Cystic fibrosis (CF) is a genetic disorder that affects breathing and digestion, requiring early diagnosis for optimal treatment. However, a recent study reveals that too many infants, especially those from minority backgrounds, receive delayed diagnoses, leading to poorer health outcomes. Susanna McColley, MD, from Lurie Children’s Hospital, led this research, underscoring the critical importance of prompt diagnosis and the need for diagnostic equity.

The Importance of Early Diagnosis

CF can be detected through newborn screening, but timely follow-up is crucial. If a screen indicates potential CF, infants should be evaluated by a pediatrician within the first month. Early diagnosis is vital because it enables early dietary interventions, which are critical for lung health and overall growth in infants with CF.

“Our research shows that diagnosing CF within 10 days of birth leads to better height and weight outcomes compared to a diagnosis at six weeks,” explained Dr. McColley. “Good nutrition in infants with CF can significantly improve lung function and lifespan.”

Historical Context and Modern Challenges

In 1938, CF was described, and it was often fatal in early childhood. However, advances in diagnosis and treatment have improved life expectancy to 61 years for people with CF born between 2019 and 2023. Despite these improvements, disparities persist in the diagnosis of CF among different racial and ethnic groups.

Incidentally, these minorities, representing 22 percent of newly diagnosed CF cases in 2023, face specific challenges in timely diagnosis. One significant factor is diagnostic bias, rooted in the misconception that CF is predominantly a disease of European ancestry.

Unveiling Diagnostic Bias

Dr. McColley elaborates on how medical literature and education perpetuate the misconception that CF is a concern primarily for White babies. Textbooks and studies often portray CF as the most common genetic fatal disease in people of European ancestry, leading to diagnostic bias against minority infants.

Another aspect of diagnostic challenges is the genetic variants detected in newborn screening. Screening panels are often limited, focusing on variants common in European populations. As a result, infants with rarer genetic variants may not be identified, leading to delays in diagnosis.

Understanding Newborn Screening Limitations

An infant with CF inherits two variants of the CF-causing gene, one from each parent. Over 1,000 gene variants have been linked to CF, but many states use screening panels that detect only the most common variants. This limitation can result in false-negative or ambiguous results, especially for infants from minority backgrounds.

“Current newborn screening panels miss variants that are less common or absent in European populations,” Dr. McColley said. “Improving these panels to include a wider range of genetic variants can help identify more infants with CF, irrespective of their racial or ethnic background.”

Implications of Diagnostic Delays

Delays in diagnosing CF can have severe consequences, particularly for growth and lung function in young children. Infants with CF who receive late diagnoses often exhibit poorer growth during their preschool years, which can increase the risk of complications and early mortality.

Moreover, some infants with CF have only one variant detected during newborn screening. These cases, accounting for one in 10 CF diagnoses, often result in delayed diagnosis and increased health risks.

The Role of Symptoms in Early Diagnosis

Parents and healthcare providers must be vigilant for early signs of CF, such as bowel obstruction and poor weight gain, even if newborn screening results are normal. Prompt referral for diagnostic evaluation is essential when symptoms appear, regardless of screening results.

“Symptoms can also be delayed,” Dr. McColley notes. “Therefore, ongoing vigilance and immediate action when symptoms arise are crucial for early diagnosis and effective treatment.”

Calls for Action and Further Research

Addressing diagnostic disparities in CF requires a multifaceted approach. Dr. McColley advocates for increased awareness and education to dispel misconceptions about CF and promote early diagnosis among all infants.

“Raising awareness and educating healthcare providers about CF’s potential in all racial and ethnic backgrounds is essential,” Dr. McColley states. “Additionally, improving newborn screening panels to include less common genetic variants will enhance diagnostic accuracy and equity.”

Dr. McColley’s work, supported by the Rosenau Family Research Foundation, has highlighted the need for ongoing research to ensure equitable and effective diagnosis and treatment of CF.

To learn more about CF and newborn screening, access the recent Cystic Fibrosis National Indicator Report 2024, co-authored by Dr. McColley and funded by the Centers for Disease Control and Prevention (CDC).

Dr. McColley discusses her research on newborn screening and efforts to promote equity in early diagnosis and care for CF on the In Pursuit podcast from Stanley Manne Children’s Research Institute at Lurie Children’s.

Join the Conversation

What are your thoughts on this research? How can we improve early diagnosis of cystic fibrosis for all children? Share your insights in the comments below or subscribe to receive more updates on advancements in pediatric health.