Noonan syndrome
Last updated 18 Aug 2020
Meets Patient’s editorial guidelines
- DownloadDownload
- Share
- Language
- Discussion
- Audio Version
- Add to preferred sources on Google
Noonan syndrome is a condition that affects many areas of the body. It is characterised by mildly unusual facial features, short stature, heart defects, bleeding problems, skeletal malformations, and many other signs and symptoms.
Description
Noonan syndrome is a condition that affects many areas of the body. It is characterised by mildly unusual facial features, short stature, heart defects, bleeding problems, skeletal malformations, and many other signs and symptoms.
People with Noonan syndrome have distinctive facial features such as a deep groove in the area between the nose and mouth (philtrum), widely spaced eyes that are usually pale blue or blue-green in colour, and low-set ears that are rotated backward. Affected individuals may have a high arch in the roof of the mouth (high-arched palate), poor teeth alignment, and a small lower jaw (micrognathia). Many children with Noonan syndrome have a short neck, and both children and adults may have excess neck skin (also called webbing) and a low hairline at the back of the neck.
Between 50 and 70 percent of individuals with Noonan syndrome have short stature. At birth, they are usually a normal length and weight, but growth slows over time. Abnormal levels of growth hormone, a protein that is necessary for the normal growth of the body's bones and tissues, may contribute to the slow growth.
Individuals with Noonan syndrome often have either a sunken chest (pectus excavatum) or a protruding chest (pectus carinatum). Some affected people may also have an abnormal side-to-side curvature of the spine (scoliosis).
Most people with Noonan syndrome have some form of critical congenital heart disease. The most common heart defect in these individuals is a narrowing of the valve that controls blood flow from the heart to the lungs (pulmonary valve stenosis). Some have hypertrophic cardiomyopathy, which enlarges and weakens the heart muscle.
A variety of bleeding disorders have been associated with Noonan syndrome. Some affected individuals have excessive bruising, nosebleeds, or prolonged bleeding following injury or surgery. Rarely, women with Noonan syndrome who have a bleeding disorder have excessive bleeding during menstruation (menorrhagia) or childbirth.
Adolescent males with Noonan syndrome typically experience delayed puberty. They go through puberty starting at age 13 or 14 and have a reduced pubertal growth spurt that results in shortened stature. Most males with Noonan syndrome have undescended testes (cryptorchidism), which may contribute to infertility (inability to father a child) later in life. Females with Noonan syndrome can experience delayed puberty but most have normal puberty and fertility.
Noonan syndrome can cause a variety of other signs and symptoms. Most children diagnosed with Noonan syndrome have normal intelligence, but a few have special educational needs, and some have intellectual disability. Some affected individuals have vision or hearing problems. Affected infants may have feeding problems, which typically get better by age 1 or 2 years. Infants with Noonan syndrome may be born with puffy hands and feet caused by a buildup of fluid (lymphedema), which can go away on its own. Older individuals can also develop lymphedema, usually in the ankles and lower legs.
Some people with Noonan syndrome develop cancer, particularly those involving the blood-forming cells (leukemia). It has been estimated that children with Noonan syndrome have an eightfold increased risk of developing leukemia or other cancers over age-matched peers.
Noonan syndrome is one of a group of related conditions, collectively known as RASopathies. These conditions all have similar signs and symptoms and are caused by changes in the same cell signaling pathway. In addition to Noonan syndrome, the RASopathies include cardiofaciocutaneous syndrome, Costello syndrome, neurofibromatosis type 1, Legius syndrome, and Noonan syndrome with multiple lentigines.
Inheritance patterns
The source lists the following possible inheritance patterns: Autosomal dominant. More than one pattern can apply in different cases.
Related genes
Other names
Familial Turner syndrome
Female pseudo-Turner syndrome
Male Turner syndrome
Noonan's syndrome
Noonan-Ehmke syndrome
NS
Pseudo-Ullrich-Turner syndrome
Turner phenotype with normal karyotype
Turner syndrome in female with X chromosome
Turner-like syndrome
Ullrich-Noonan syndrome
Related patient information and medicines
Patient information leaflet
Restricted growth
Dwarfism is a medical or genetic condition which causes people to have restricted growth so that they are shorter than average. Specifically, people with dwarfism grow no higher than 4 ft 10 ins (147 cm). This is a rare genetic condition with many features i... It may also cause short stature. Noonan syndrome. A rare genetic condition causing many.
Patient information leaflet
Gilbert's syndrome
Gilbert's syndrome is due to an inherited defect in processing bilirubin in the liver. This is because bilirubin is an orangey-yellow colour. Although typically harmless, there has been some evidence found recently that Gilbert's syndrome may be associated with both good and bad health outcomes: There is some evidence for pr... However, Gilbert's.
Patient information leaflet
Proctalgia fugax and anal pain
Proctalgia fugax is a fleeting pain in the anus. It lasts less than 20 minutes, with no symptoms whatsoever in between episodes. Levator ani syndrome is a pain which lasts for longer. Both are only diagnosed when no other cause is found. What is proctalgia fugax. Proctalgia fugax is one of a number of conditions which cause anal or rectal pain.
Patient information leaflet
Nephrotic syndrome
Nephrotic syndrome is a condition where the 'filters' in the kidney become 'leaky' and large amounts of protein leak from the blood into the urine. The main symptom is fluid retention (oedema) which is mainly due to the low protein level in the blood. Various diseases can cause nephro... What is nephrotic syndrome. Nephrotic syndrome is not a.
Patient information leaflet
Cervical rib
About 1 in 100 people are born with an extra rib called a cervical rib. About 1 in 10 people who have a cervical rib develop thoracic outlet syndrome. This happens if the cervical rib squashes the nerves and blood vessels going into the arm. Treatment can include painkillers, physiotherapy and sometimes surgery to relieve the compression caused.
Patient information leaflet
Oral allergy syndrome
Oral allergy syndrome causes symptoms around the mouth that are triggered by certain foods. It is associated with other conditions caused by plant allergies, such as hay fever and allergy to birch pollen. It's also called pollen-food syndrom... What is oral allergy syndrome. Oral allergy syndrome (OAS) is an allergic condition which causes itching.
Further reading and references
- Noonan syndrome; MedlinePlus, National Library of Medicine.
- Chen PC, Yin J, Yu HW, Yuan T, Fernandez M, Yung CK, Trinh QM, Peltekova VD, Reid JG, Tworog-Dube E, Morgan MB, Muzny DM, Stein L, McPherson JD, Roberts AE, Gibbs RA, Neel BG, Kucherlapati R. Next-generation sequencing identifies rare variants associated with Noonan syndrome. Proc Natl Acad Sci U S A. 2014 Aug 5;111(31):11473-8. doi: 10.1073/pnas.1324128111. Epub 2014 Jul 21.
- Cordeddu V, Yin JC, Gunnarsson C, Virtanen C, Drunat S, Lepri F, De Luca A, Rossi C, Ciolfi A, Pugh TJ, Bruselles A, Priest JR, Pennacchio LA, Lu Z, Danesh A, Quevedo R, Hamid A, Martinelli S, Pantaleoni F, Gnazzo M, Daniele P, Lissewski C, Bocchinfuso G, Stella L, Odent S, Philip N, Faivre L, Vlckova M, Seemanova E, Digilio C, Zenker M, Zampino G, Verloes A, Dallapiccola B, Roberts AE, Cave H, Gelb BD, Neel BG, Tartaglia M. Activating Mutations Affecting the Dbl Homology Domain of SOS2 Cause Noonan Syndrome. Hum Mutat. 2015 Nov;36(11):1080-7. doi: 10.1002/humu.22834. Epub 2015 Aug 3.
- Flex E, Jaiswal M, Pantaleoni F, Martinelli S, Strullu M, Fansa EK, Caye A, De Luca A, Lepri F, Dvorsky R, Pannone L, Paolacci S, Zhang SC, Fodale V, Bocchinfuso G, Rossi C, Burkitt-Wright EM, Farrotti A, Stellacci E, Cecchetti S, Ferese R, Bottero L, Castro S, Fenneteau O, Brethon B, Sanchez M, Roberts AE, Yntema HG, Van Der Burgt I, Cianci P, Bondeson ML, Cristina Digilio M, Zampino G, Kerr B, Aoki Y, Loh ML, Palleschi A, Di Schiavi E, Care A, Selicorni A, Dallapiccola B, Cirstea IC, Stella L, Zenker M, Gelb BD, Cave H, Ahmadian MR, Tartaglia M. Activating mutations in RRAS underlie a phenotype within the RASopathy spectrum and contribute to leukaemogenesis. Hum Mol Genet. 2014 Aug 15;23(16):4315-27. doi: 10.1093/hmg/ddu148. Epub 2014 Apr 4.
- Kouz K, Lissewski C, Spranger S, Mitter D, Riess A, Lopez-Gonzalez V, Luttgen S, Aydin H, von Deimling F, Evers C, Hahn A, Hempel M, Issa U, Kahlert AK, Lieb A, Villavicencio-Lorini P, Ballesta-Martinez MJ, Nampoothiri S, Ovens-Raeder A, Puchmajerova A, Satanovskij R, Seidel H, Unkelbach S, Zabel B, Kutsche K, Zenker M. Genotype and phenotype in patients with Noonan syndrome and a RIT1 mutation. Genet Med. 2016 Dec;18(12):1226-1234. doi: 10.1038/gim.2016.32. Epub 2016 Apr 21.
- Kratz CP, Franke L, Peters H, Kohlschmidt N, Kazmierczak B, Finckh U, Bier A, Eichhorn B, Blank C, Kraus C, Kohlhase J, Pauli S, Wildhardt G, Kutsche K, Auber B, Christmann A, Bachmann N, Mitter D, Cremer FW, Mayer K, Daumer-Haas C, Nevinny-Stickel-Hinzpeter C, Oeffner F, Schluter G, Gencik M, Uberlacker B, Lissewski C, Schanze I, Greene MH, Spix C, Zenker M. Cancer spectrum and frequency among children with Noonan, Costello, and cardio-facio-cutaneous syndromes. Br J Cancer. 2015 Apr 14;112(8):1392-7. doi: 10.1038/bjc.2015.75. Epub 2015 Mar 5.
- Milosavljevic D, Overwater E, Tamminga S, de Boer K, Elting MW, van Hoorn ME, Rinne T, Houweling AC. Two cases of RIT1 associated Noonan syndrome: Further delineation of the clinical phenotype and review of the literature. Am J Med Genet A. 2016 Jul;170(7):1874-80. doi: 10.1002/ajmg.a.37657. Epub 2016 Apr 25.
- Roberts AE, Allanson JE, Tartaglia M, Gelb BD. Noonan syndrome. Lancet. 2013 Jan 26;381(9863):333-42. doi: 10.1016/S0140-6736(12)61023-X. Epub 2013 Jan 10.
- Rohrer T. Noonan syndrome: introduction and basic clinical features. Horm Res. 2009 Dec;72 Suppl 2:3-7. doi: 10.1159/000243772. Epub 2009 Dec 22.
- Romano AA, Allanson JE, Dahlgren J, Gelb BD, Hall B, Pierpont ME, Roberts AE, Robinson W, Takemoto CM, Noonan JA. Noonan syndrome: clinical features, diagnosis, and management guidelines. Pediatrics. 2010 Oct;126(4):746-59. doi: 10.1542/peds.2009-3207. Epub 2010 Sep 27.
- Schubbert S, Zenker M, Rowe SL, Boll S, Klein C, Bollag G, van der Burgt I, Musante L, Kalscheuer V, Wehner LE, Nguyen H, West B, Zhang KY, Sistermans E, Rauch A, Niemeyer CM, Shannon K, Kratz CP. Germline KRAS mutations cause Noonan syndrome. Nat Genet. 2006 Mar;38(3):331-6. doi: 10.1038/ng1748. Epub 2006 Feb 12.
- Sznajer Y, Keren B, Baumann C, Pereira S, Alberti C, Elion J, Cave H, Verloes A. The spectrum of cardiac anomalies in Noonan syndrome as a result of mutations in the PTPN11 gene. Pediatrics. 2007 Jun;119(6):e1325-31. doi: 10.1542/peds.2006-0211. Epub 2007 May 21.
- Tartaglia M, Pennacchio LA, Zhao C, Yadav KK, Fodale V, Sarkozy A, Pandit B, Oishi K, Martinelli S, Schackwitz W, Ustaszewska A, Martin J, Bristow J, Carta C, Lepri F, Neri C, Vasta I, Gibson K, Curry CJ, Siguero JP, Digilio MC, Zampino G, Dallapiccola B, Bar-Sagi D, Gelb BD. Gain-of-function SOS1 mutations cause a distinctive form of Noonan syndrome. Nat Genet. 2007 Jan;39(1):75-9. doi: 10.1038/ng1939. Epub 2006 Dec 13.
- van der Burgt I. Noonan syndrome. Orphanet J Rare Dis. 2007 Jan 14;2:4. doi: 10.1186/1750-1172-2-4.
- Vissers LE, Bonetti M, Paardekooper Overman J, Nillesen WM, Frints SG, de Ligt J, Zampino G, Justino A, Machado JC, Schepens M, Brunner HG, Veltman JA, Scheffer H, Gros P, Costa JL, Tartaglia M, van der Burgt I, Yntema HG, den Hertog J. Heterozygous germline mutations in A2ML1 are associated with a disorder clinically related to Noonan syndrome. Eur J Hum Genet. 2015 Mar;23(3):317-24. doi: 10.1038/ejhg.2014.115. Epub 2014 Jun 18.
- Yamamoto GL, Aguena M, Gos M, Hung C, Pilch J, Fahiminiya S, Abramowicz A, Cristian I, Buscarilli M, Naslavsky MS, Malaquias AC, Zatz M, Bodamer O, Majewski J, Jorge AA, Pereira AC, Kim CA, Passos-Bueno MR, Bertola DR. Rare variants in SOS2 and LZTR1 are associated with Noonan syndrome. J Med Genet. 2015 Jun;52(6):413-21. doi: 10.1136/jmedgenet-2015-103018. Epub 2015 Mar 20.
Join the conversation
Share your thoughts or experiences with others in our patient communities.
Ask, share, connect.
Browse discussions, ask questions, and share experiences across hundreds of health topics.
Sign up to the Patient newsletter
Your weekly dose of clear, trustworthy health advice - written to help you feel informed, confident and in control.
By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.