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Noonan syndrome 6(NS6)

MedGen UID:
413028
Concept ID:
C2750732
Disease or Syndrome
Synonyms: Noonan Syndrome; NRAS gene related Noonan syndrome; NRAS-Related Noonan Syndrome; NS6
 
Gene (location): NRAS (1p13.2)
OMIM®: 613224

Disease characteristics

Excerpted from the GeneReview: Noonan Syndrome
Noonan syndrome (NS) is characterized by characteristic facies, short stature, congenital heart defect, and developmental delay of variable degree. Other findings can include broad or webbed neck, unusual chest shape with superior pectus carinatum and inferior pectus excavatum, cryptorchidism, varied coagulation defects, lymphatic dysplasias, and ocular abnormalities. Although birth length is usually normal, final adult height approaches the lower limit of normal. Congenital heart disease occurs in 50%-80% of individuals. Pulmonary valve stenosis, often with dysplasia, is the most common heart defect and is found in 20%-50% of individuals. Hypertrophic cardiomyopathy, found in 20%-30% of individuals, may be present at birth or develop in infancy or childhood. Other structural defects include atrial and ventricular septal defects, branch pulmonary artery stenosis, and tetralogy of Fallot. Up to one fourth of affected individuals have mild intellectual disability, and language impairments in general are more common in NS than in the general population. [from GeneReviews]
Authors:
Judith E Allanson  |  Amy E Roberts   view full author information

Additional description

From GHR
Noonan syndrome is a condition that affects many areas of the body. It is characterized 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 color, 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.  https://ghr.nlm.nih.gov/condition/noonan-syndrome

Clinical features

Hypertelorism
MedGen UID:
9373
Concept ID:
C0020534
Congenital Abnormality
Although hypertelorism means an excessive distance between any paired organs (e.g., the nipples), the use of the word has come to be confined to ocular hypertelorism. Hypertelorism occurs as an isolated feature and is also a feature of many syndromes, e.g., Opitz G syndrome (145410), Greig cephalopolysyndactyly (175700), and Noonan syndrome (163950) (summary by Cohen et al., 1995).
Myopia
MedGen UID:
44558
Concept ID:
C0027092
Disease or Syndrome
An abnormality of refraction characterized by the ability to see objects nearby clearly, while objects in the distance appear blurry.
Hypertrophic cardiomyopathy
MedGen UID:
2881
Concept ID:
C0007194
Disease or Syndrome
Hypertrophic cardiomyopathy (HCM) is defined by the presence of increased ventricular wall thickness or mass in the absence of loading conditions (hypertension, valve disease) sufficient to cause the observed abnormality.
Pulmonic stenosis
MedGen UID:
408291
Concept ID:
C1956257
Disease or Syndrome
Narrowing of the opening between the pulmonary artery and the right ventricle, usually at the level of the valve leaflets.
Short stature
MedGen UID:
87607
Concept ID:
C0349588
Finding
Height greater than two standard deviations below the mean of the appropriate reference population for the age and sex of the individual.
Low-set ears
MedGen UID:
65980
Concept ID:
C0239234
Congenital Abnormality
Upper insertion of the ear to the scalp below an imaginary horizontal line drawn between the inner canthi of the eye and extending posteriorly to the ear.
Intellectual disability, mild
MedGen UID:
10044
Concept ID:
C0026106
Mental or Behavioral Dysfunction
Mild intellectual disability is defined as an intelligence quotient (IQ) in the range of 50-69.
Delayed speech and language development
MedGen UID:
105318
Concept ID:
C0454644
Sign or Symptom
A degree of language development that is significantly below the norm for a child of a specified age.
Cryptorchidism, unilateral or bilateral
MedGen UID:
8192
Concept ID:
C0010417
Congenital Abnormality
Cryptorchidism, or failure of testicular descent, is a common human congenital abnormality with a multifactorial etiology that likely reflects the involvement of endocrine, environmental, and hereditary factors. Cryptorchidism can result in infertility and increases risk for testicular tumors. Testicular descent from abdomen to scrotum occurs in 2 distinct phases: the transabdominal phase and the inguinoscrotal phase (summary by Gorlov et al., 2002).
Generalized hypotonia
MedGen UID:
346841
Concept ID:
C1858120
Finding
Generalized muscular hypotonia (abnormally low muscle tone).
Asymmetry of the thorax
MedGen UID:
387970
Concept ID:
C1858033
Finding
Lack of symmetry between the left and right halves of the thorax.
Macrocephaly
MedGen UID:
745757
Concept ID:
C2243051
Finding
Macrocephaly refers to an abnormally enlarged head inclusive of the scalp, cranial bones, and intracranial contents. Macrocephaly may be due to megalencephaly (true enlargement of the brain parenchyma), and the 2 terms are often used interchangeably in the genetic literature (reviews by Olney, 2007 and Williams et al., 2008). Autosomal recessive macrocephaly/megalencephaly syndrome is characterized by an enlarged cranium apparent at birth or in early childhood. Affected individuals have intellectual disability and may have dysmorphic facial features resulting from the macrocephaly (summary by Alfaiz et al., 2014).
Hypertelorism
MedGen UID:
9373
Concept ID:
C0020534
Congenital Abnormality
Although hypertelorism means an excessive distance between any paired organs (e.g., the nipples), the use of the word has come to be confined to ocular hypertelorism. Hypertelorism occurs as an isolated feature and is also a feature of many syndromes, e.g., Opitz G syndrome (145410), Greig cephalopolysyndactyly (175700), and Noonan syndrome (163950) (summary by Cohen et al., 1995).
Webbed neck
MedGen UID:
113154
Concept ID:
C0221217
Congenital Abnormality
Pterygium colli is a congenital skin fold that runs along the sides of the neck down to the shoulders. It involves an ectopic fibrotic facial band superficial to the trapezius muscle. Excess hair-bearing skin is also present and extends down the cervical region well beyond the normal hairline.
Macrocephaly
MedGen UID:
745757
Concept ID:
C2243051
Finding
Macrocephaly refers to an abnormally enlarged head inclusive of the scalp, cranial bones, and intracranial contents. Macrocephaly may be due to megalencephaly (true enlargement of the brain parenchyma), and the 2 terms are often used interchangeably in the genetic literature (reviews by Olney, 2007 and Williams et al., 2008). Autosomal recessive macrocephaly/megalencephaly syndrome is characterized by an enlarged cranium apparent at birth or in early childhood. Affected individuals have intellectual disability and may have dysmorphic facial features resulting from the macrocephaly (summary by Alfaiz et al., 2014).
Curly hair
MedGen UID:
488919
Concept ID:
C0558165
Finding
Hyperkeratosis
MedGen UID:
209030
Concept ID:
C0870082
Disease or Syndrome
Hyperkeratosis is thickening of the outer layer of the skin, the stratum corneum, which is composed of large, polyhedral, plate-like envelopes filled with keratin which are the dead cells that have migrated up from the stratum granulosum.

Professional guidelines

PubMed

Romano AA, Allanson JE, Dahlgren J, Gelb BD, Hall B, Pierpont ME, Roberts AE, Robinson W, Takemoto CM, Noonan JA
Pediatrics 2010 Oct;126(4):746-59. Epub 2010 Sep 27 doi: 10.1542/peds.2009-3207. PMID: 20876176

Recent clinical studies

Etiology

Roelofs RL, Janssen N, Wingbermühle E, Kessels RP, Egger JI
Brain Behav 2016 Jul;6(7):e00479. Epub 2016 May 3 doi: 10.1002/brb3.479. PMID: 27247851Free PMC Article
van Trier DC, van Nierop J, Draaisma JM, van der Burgt I, Kunst H, Croonen EA, Admiraal RJ
Int J Pediatr Otorhinolaryngol 2015 Jun;79(6):874-8. Epub 2015 Apr 1 doi: 10.1016/j.ijporl.2015.03.021. PMID: 25862627
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
J Med Genet 2015 Jun;52(6):413-21. Epub 2015 Mar 20 doi: 10.1136/jmedgenet-2015-103018. PMID: 25795793
Smpokou P, Zand DJ, Rosenbaum KN, Summar ML
Clin Genet 2015 Dec;88(6):516-22. Epub 2015 Mar 4 doi: 10.1111/cge.12568. PMID: 25683281
Colquitt JL, Noonan JA
Congenit Heart Dis 2014 Mar-Apr;9(2):144-50. Epub 2013 Jun 10 doi: 10.1111/chd.12102. PMID: 23750712

Diagnosis

Kneitel AW, Norby A, Vettraino I, Treadwell MC
Fetal Pediatr Pathol 2015;34(6):361-4. Epub 2015 Oct 14 doi: 10.3109/15513815.2015.1087609. PMID: 26467173
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
J Med Genet 2015 Jun;52(6):413-21. Epub 2015 Mar 20 doi: 10.1136/jmedgenet-2015-103018. PMID: 25795793
Loddo I, Romano C, Cutrupi MC, Sciveres M, Riva S, Salpietro A, Ferraù V, Gallizzi R, Briuglia S
Eur J Med Genet 2015 Mar;58(3):188-90. Epub 2015 Jan 13 doi: 10.1016/j.ejmg.2014.12.013. PMID: 25595571
Nair S, Fort JA, Yachnis AT, Williams CA
Pediatr Blood Cancer 2015 Jun;62(6):1084-6. Epub 2015 Jan 13 doi: 10.1002/pbc.25382. PMID: 25585602
Colquitt JL, Noonan JA
Congenit Heart Dis 2014 Mar-Apr;9(2):144-50. Epub 2013 Jun 10 doi: 10.1111/chd.12102. PMID: 23750712

Therapy

Zavras N, Meazza C, Pilotta A, Gertosio C, Pagani S, Tinelli C, Bozzola M
Ital J Pediatr 2015 Oct 6;41:71. doi: 10.1186/s13052-015-0183-x. PMID: 26444854Free PMC Article
Giacomozzi C, Deodati A, Shaikh MG, Ahmed SF, Cianfarani S
Horm Res Paediatr 2015;83(3):167-76. Epub 2015 Feb 21 doi: 10.1159/000371635. PMID: 25721697
Noonan JA, Kappelgaard AM
Horm Res Paediatr 2015;83(3):157-66. Epub 2014 Dec 10 doi: 10.1159/000369012. PMID: 25503994
Fuchs S, Gat-Yablonski G, Shtaif B, Lazar L, Phillip M, Lebenthal Y
J Endocrinol Invest 2015 Apr;38(4):399-406. Epub 2014 Oct 26 doi: 10.1007/s40618-014-0194-2. PMID: 25344824
Tofil NM, Winkler MK, Watts RG, Noonan J
Pediatr Crit Care Med 2005 May;6(3):352-4. doi: 10.1097/01.PCC.0000160656.71424.D1. PMID: 15857538

Prognosis

Roelofs RL, Janssen N, Wingbermühle E, Kessels RP, Egger JI
Brain Behav 2016 Jul;6(7):e00479. Epub 2016 May 3 doi: 10.1002/brb3.479. PMID: 27247851Free PMC Article
Noonan JA, Kappelgaard AM
Horm Res Paediatr 2015;83(3):157-66. Epub 2014 Dec 10 doi: 10.1159/000369012. PMID: 25503994
Colquitt JL, Noonan JA
Congenit Heart Dis 2014 Mar-Apr;9(2):144-50. Epub 2013 Jun 10 doi: 10.1111/chd.12102. PMID: 23750712
Nosan G, Bertok S, Vesel S, Yntema HG, Paro-Panjan D
Croat Med J 2013 Dec;54(6):574-8. PMID: 24382853Free PMC Article
Bertelloni S, Baroncelli GI, Dati E, Ghione S, Baldinotti F, Toschi B, Simi P
Hormones (Athens) 2013 Jan-Mar;12(1):86-92. PMID: 23624134

Clinical prediction guides

Roelofs RL, Janssen N, Wingbermühle E, Kessels RP, Egger JI
Brain Behav 2016 Jul;6(7):e00479. Epub 2016 May 3 doi: 10.1002/brb3.479. PMID: 27247851Free PMC Article
Niemczyk J, Equit M, Borggrefe-Moussavian S, Curfs L, von Gontard A
J Pediatr Urol 2015 Aug;11(4):201.e1-5. Epub 2015 Jun 18 doi: 10.1016/j.jpurol.2015.06.002. PMID: 26143485
Giacomozzi C, Deodati A, Shaikh MG, Ahmed SF, Cianfarani S
Horm Res Paediatr 2015;83(3):167-76. Epub 2015 Feb 21 doi: 10.1159/000371635. PMID: 25721697
Noonan JA, Kappelgaard AM
Horm Res Paediatr 2015;83(3):157-66. Epub 2014 Dec 10 doi: 10.1159/000369012. PMID: 25503994
Bertelloni S, Baroncelli GI, Dati E, Ghione S, Baldinotti F, Toschi B, Simi P
Hormones (Athens) 2013 Jan-Mar;12(1):86-92. PMID: 23624134

Recent systematic reviews

Schütte P, Möricke A, Zimmermann M, Bleckmann K, Reismüller B, Attarbaschi A, Mann G, Bodmer N, Niggli F, Schrappe M, Stanulla M, Kratz CP
Eur J Med Genet 2016 Mar;59(3):143-51. Epub 2015 Dec 28 doi: 10.1016/j.ejmg.2015.12.008. PMID: 26732628
Giacomozzi C, Deodati A, Shaikh MG, Ahmed SF, Cianfarani S
Horm Res Paediatr 2015;83(3):167-76. Epub 2015 Feb 21 doi: 10.1159/000371635. PMID: 25721697

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