Noonan syndrome
| Noonan syndrome | |
|---|---|
| Other names | Male Turner syndrome, Noonan–Ehmke syndrome, Turner-like syndrome, Ullrich–Noonan syndrome[1] |
| A 12-year-old girl with Noonan syndrome, displaying typical webbed neck and double structural curve with rib deformity. | |
| Specialty | Medical genetics, pediatrics |
| Symptoms | Mildly unusual facial features, short height, congenital heart disease, bleeding problems, skeletal malformations[1] |
| Complications | Leukemia[1] |
| Usual onset | Present at birth[2] |
| Types | Type 1 to 6[3] |
| Causes | Genetic mutation (autosomal dominant)[1] |
| Diagnostic method | Suspected based on symptoms, confirmed with genetic testing[4][2] |
| Differential diagnosis | Cardiofaciocutaneous syndrome, Turner syndrome, Costello syndrome, neurofibromatosis type 1[2][3] |
| Treatment | Based on the symptoms[3] |
| Medication | Growth hormone[3] |
| Prognosis | Depends on the severity of heart problems[3] |
| Frequency | 1 in 1000 (1 in 2,000 severe disease)[4] |
| Named after | Jacqueline Noonan |
Noonan syndrome (NS) is a genetic disorder that may present with mildly unusual facial features, short height, congenital heart disease, bleeding problems, and skeletal malformations.[1] Facial features include widely spaced eyes, light-colored eyes, low-set ears, a short neck, and a small lower jaw.[1] Heart problems may include pulmonary valve stenosis.[1] The breast bone may either protrude or be sunken, while the spine may be abnormally curved.[1] Intelligence is often normal.[1] Complications of NS can include leukemia.[1] Some of NS' symptoms are shared with Watson syndrome, a related genetic condition.[5]
A number of genetic mutations can result in Noonan syndrome.[1] The condition may be inherited as an autosomal dominant condition or occur as a new mutation.[3][1] Noonan syndrome is a type of RASopathy,[5] the underlying mechanism for which involves sustained activation of the RAS/MAPK cell signaling pathway.[1] The diagnosis may be suspected based on symptoms, medical imaging, and blood tests.[2][4] Confirmation may be achieved with genetic testing.[2]
No cure for NS is known.[6] Treatment is based on the symptoms and underlying problems, and extra support in school may be required.[3] Growth hormone therapy during childhood can increase an affected person's final height.[3] Long-term outcomes typically depend on the severity of heart problems.[3]
An estimated 1 in 1,000 people are mildly affected by NS, while about 1 in 2,000 have a more severe form of the condition.[4] Males appear to be affected more often than females.[2] The condition was named after American pediatric cardiologist Jacqueline Noonan, who described her first case in 1963.[2]
- ^ a b c d e f g h i j k l m "Noonan syndrome". Genetics Home Reference. Retrieved 24 December 2018.
- ^ a b c d e f g "Noonan Syndrome". NORD (National Organization for Rare Disorders). 2016. Retrieved 24 December 2018.
- ^ a b c d e f g h i "Noonan syndrome". Genetic and Rare Diseases Information Center (GARD) – an NCATS Program. Retrieved 25 December 2018.
- ^ a b c d Bhambhani V, Muenke M (January 2014). "Noonan syndrome". American Family Physician. 89 (1): 37–43. PMC 4099190. PMID 24444506.
- ^ a b Boxel-Woolf, Tom Van; McCarthy, Kathleen M. (2025). "Speech and language skills in a case of Watson syndrome". Clinical Linguistics & Phonetics. 0: 1–24. doi:10.1080/02699206.2025.2472051. ISSN 0269-9206. PMID 40077991.
- ^ "Noonan Syndrome - Children's Health Issues". Merck Manuals Consumer Version. Retrieved 25 December 2018.