11 Surprising Symptoms Associated With Noonan Syndrome

7. Gastrointestinal and Feeding Challenges

Many infants and young children with Noonan syndrome experience significant feeding difficulties, which can lead to failure to thrive in infancy. Issues may include gastroesophageal reflux disease (GERD), difficulty swallowing (dysphagia), poor sucking ability, and delayed progression to solid foods. These challenges can make weight gain difficult and often require medical intervention such as specialized feeding therapy, tube feeding, or medications to manage reflux. Even in older children and adults, gastrointestinal issues like chronic constipation, bloating, and irritable bowel syndrome (IBS)-like symptoms may persist. Addressing these issues with dietary modifications, probiotics, and digestive enzyme support can improve quality of life.

8. Curly or Sparse Hair and Brittle Nails

Noonan syndrome is often associated with distinctive hair and nail changes, which many people don’t immediately recognize as related to the condition. Patients frequently have thin, sparse, or slow-growing hair, which may be curly, coarse, or brittle. Some may experience early hair thinning or hair loss, especially around the temples. Nails are often thin, brittle, or ridged, making them prone to splitting or breaking. These features are thought to be linked to abnormal connective tissue function, which also contributes to loose skin and joint hypermobility in some patients. While these symptoms are not dangerous, they can be frustrating, especially for those struggling with self-image. Nutritional support, gentle hair care routines, and hydration can help improve hair and nail health.