Cranial abnormalities were identified in 54.1% of patients with Noonan syndrome, encompassing a broad spectrum from structural anomalies to clinically significant neoplastic lesions, supporting consideration of cranial MRI at the time of diagnosis, particularly before initiation of growth hormone therapy.
Cranial abnormalities were identified in more than half of patients with Noonan syndrome.
Some intracranial lesions in Noonan syndrome patients were asymptomatic, suggesting clinical evaluation alone is insufficient for their detection.
No newly detected pathologies or malignancies were identified during follow-up in Noonan syndrome patients receiving recombinant growth hormone therapy.
The spectrum of cranial MRI findings in Noonan syndrome patients included both structural anomalies and clinically significant neoplastic lesions.
The authors recommend consideration of cranial MRI at the time of Noonan syndrome diagnosis, particularly before initiation of growth hormone therapy.
This research suggests that brain abnormalities are surprisingly common in people with Noonan syndrome, a genetic condition caused by mutations in a specific cellular signaling pathway. By reviewing 25 years of patient records and brain MRI scans, researchers found that more than half of Noonan syndrome patients (54.1%) had some kind of abnormality visible on brain MRI. These ranged from structural differences in brain anatomy to more serious findings such as brain tumors. Importantly, some of these significant findings were present in patients who had no symptoms, meaning they would not have been caught through routine physical examination alone. This research also addresses a specific concern for Noonan syndrome patients who may be prescribed growth hormone therapy to address short stature — a common feature of the condition. Because Noonan syndrome is linked to a pathway associated with increased cancer and tumor risk, there has been uncertainty about whether growth hormone treatment might stimulate tumor growth. This study found that none of the patients receiving growth hormone therapy developed new brain lesions or malignancies during follow-up, providing reassuring evidence for the safety of this treatment in this population. The practical implication of these findings is that a brain MRI scan at the time of Noonan syndrome diagnosis — before starting growth hormone therapy — could help identify hidden but clinically important abnormalities that would otherwise go undetected. The researchers suggest this approach could enable earlier treatment of relevant lesions and provide a clearer baseline for monitoring patients who go on to receive growth hormone therapy.
Şen E, Çetin S, Şahap S, Fitöz &, Dikmen &, Kayakıran E, et al.. (2026). Cranial pathologies in Noonan syndrome: clinical implications for pre-growth hormone neuroimaging.. European journal of pediatrics. https://doi.org/10.1007/s00431-026-07361-z