Diseases

Noonan Syndrome

A genetically heterogeneous, multifaceted disorder characterized by short stature, webbed neck, ptosis, skeletal malformations, hypertelorism, hormonal imbalance, CRYPTORCHIDISM, multiple cardiac abnormalities (most commonly including PULMONARY VALVE STENOSIS), and some degree of INTELLECTUAL DISABILITY. The phenotype bears similarities to that of TURNER SYNDROME that occurs only in females and has its basis in a 45, X karyotype abnormality. Noonan syndrome occurs in both males and females with a normal karyotype (46,XX and 46,XY). Mutations in a several genes (PTPN11, KRAS, SOS1, NF1 and RAF1) have been associated the NS phenotype. Mutations in PTPN11 are the most common. LEOPARD SYNDROME, a disorder that has clinical features overlapping those of Noonan Syndrome, is also due to mutations in PTPN11. In addition, there is overlap with the syndrome called neurofibromatosis-Noonan syndrome due to mutations in NF1.

National Library of MedicineMedical Subject Headings2026

Structured Summary

Abstract

A genetically heterogeneous, multifaceted disorder characterized by short stature, webbed neck, ptosis, skeletal malformations, hypertelorism, hormonal imbalance, CRYPTORCHIDISM, multiple cardiac abnormalities (most commonly including PULMONARY VALVE STENOSIS), and some degree of INTELLECTUAL DISABILITY. The phenotype bears similarities to that of TURNER SYNDROME that occurs only in females and has its basis in a 45, X karyotype abnormality. Noonan syndrome occurs in both males and females with a normal karyotype (46,XX and 46,XY). Mutations in a several genes (PTPN11, KRAS, SOS1, NF1 and RAF1) have been associated the NS phenotype. Mutations in PTPN11 are the most common. LEOPARD SYNDROME, a disorder that has clinical features overlapping those of Noonan Syndrome, is also due to mutations in PTPN11. In addition, there is overlap with the syndrome called neurofibromatosis-Noonan syndrome due to mutations in NF1.

MeSH Record

Classification

Broader headings

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MeSH Record

See Also

MeSH Record

Synonyms

20 entry terms
  • Familial Turner Syndrome
  • Noonan-Ehmke Syndrome
  • Pseudo-Ullrich-Turner Syndrome
  • Turner Phenotype with Normal Karyotype
  • Turner's Phenotype, Karyotype Normal
  • Turner-Like Syndrome
  • Ullrich-Noonan Syndrome
  • Noonan Ehmke Syndrome
  • Pseudo Ullrich Turner Syndrome
  • Turner Like Syndrome
  • Turner Syndrome, Familial
  • Ullrich Noonan Syndrome
  • Female Pseudo-Turner Syndrome
  • Male Turner Syndrome
  • Noonan Syndrome 1
  • Turner Syndrome, Male
  • Turner's Syndrome, Male
  • Female Pseudo Turner Syndrome
  • Male Turner's Syndrome
  • Pseudo-Turner Syndrome, Female

MeSH Record

Aspects Covered

34 allowable subheadings

Indexed with the subheadings blood, cerebrospinal fluid, chemically induced, classification, complications, diagnosis, diagnostic imaging, diet therapy, drug therapy, economics, embryology, enzymology, epidemiology, ethnology, etiology, genetics, history, immunology, metabolism, microbiology, mortality, nursing, parasitology, pathology, physiopathology, prevention & control, psychology, radiotherapy, rehabilitation, surgery, therapy, urine, veterinary, virology.

MeSH Record

History Note

1979

MeSH Record

Previous Indexing

  • Turner's Syndrome (1966-1978)

MeSH Hierarchy

Tree Numbers

  1. C05w.660w.207w.690w
  2. C14w.240.400w.787w
  3. C14w.280w.400w.787w
  4. C16w.131w.240.400w.784w
  5. C16w.131w.621w.207w.690w
  6. C17.300w.690w

MeSH Record

NLM Classification

QS 675

AMA Style

References

  1. National Library of Medicine. Noonan Syndrome. Medical Subject Headings (MeSH). 2026. Unique ID D009634. http://id.nlm.nih.gov/mesh/2026/D009634
  2. Noonan Syndrome. In: Wikipedia. https://en.wikipedia.org/wiki/Noonan_syndrome
  3. Noonan Syndrome. In: Wikidata. https://www.wikidata.org/wiki/Q1543446