Noonan syndrome

Description

Noonan’s syndrome is an autosomal dominant genetic condition with mutations affecting the RAS signaling pathway.  It is still primarily a clinical diagnosis. Incidence is thought to be around 1 in 1,000-2500 live births. There is high variability in presentation but characteristic features include: short stature, chest deformity, facial features and cardiac disease. It is the second most common genetic syndrome associated with congenital cardiac defects, most commonly hypertrophic cardiomyopathy and pulmonary stenosis.


History

1883 – An early description of the Noonan syndrome was provided Oskar Kobyliński (1856-1926), a medical student at the University of Dorpat. He described the case of the 20-year-old Leisar Eischikmann admitted for investigation of a fever of unknown origin. Kobyliński published the case in Archiv für Anthropologie and defined in great detail an anatomical abnormality of webbing of the neck. He also drew attention to the patient’s low hairline; that at the level of the nasal bridge the hairline connected with the eyebrows; and bilateral deformation of the external ear of the patient.

**Funke, Ullrich and Turner quote the case of Kobyliński, however the case is more likely Noonan syndrome. This led to endless confusion in the literature until the cytogenetic clarification of both entities.

Kobyliński 1883 first description of Noonan Syndrome
First description of Noonan Syndrome. Kobyliński 1883: Taf XIV

1962Jacqueline Noonan (1921 – ) and Dorothy A. Ehmke (1920-2000) presented at the Midwest Society for Pediatric Research in 1962 the clinical study of associated non-cardiac malformations in 833 children with congenital heart disease and described nine patients who shared a phenotype suggestive of Turner syndrome, all of whom had valvular pulmonary stenosis. Noonan felt this represented a new syndrome because it occurred in both males and females, had normal chromosomes, was associated with a congenital cardiac defect and could be inherited. 

Of particular interest was the recognition of a previously unreported syndrome in 9 patients with valvular pulmonary stenosis. These children were characterized by small stature, hypertelorism, mild mental retardation, and in some instances by ptosis, undescended testes, and skeletal malformations. There were 6 males and 3 females who fit this syndrome and resembled each other in a striking manner.

Noonan, Ehmke 1962

1965Dr. John M Opitz (1935 – ) was a first year pediatric resident in the Department of Pediatrics, Iowa City where Noonan was a faculty member from 1959-1961. He moved to Madison, Wisconsin to complete his pediatric training, and noted a number of children, similar to the ones he had seen with Dr. Noonan. These individuals had small stature, hypertelorism, mild mental retardation; ptosis; skeletal abnormalities, and undescended testes in the males. Pulmonary stenosis was the most frequent cardiac defect. The chromosomes in these patients were normal and Opitz considered that they could clearly be distinguished from Ullrich-Turner syndrome. He published an abstract “Noonan Syndrome in Girls: A Genocopy of the Ullrich-Turner syndrome” 

1968 – Noonan published her report of 19 patients. Of note, four other papers appeared in the same October issue of American journal of diseases of children. 1968; 116(4)) describing similar patients. Three of the papers used the term “Turner phenotype” and two used the term Noonan syndrome.

Nineteen patients with multiple congenital anomalies were seen who seem to fit a definite syndrome. All share a rather characteristic similar facies, and 17 were quite short in stature. Although normal secondary sex characteristics eventually develop, puberty is delayed. Mental retardation is frequent but is not a constant finding. All of these patients had congenital heart disease, with valvular pulmonary stenosis present in 17 and a patent ductus arteriosus in two patients. The syndrome occurs in both males and females. There is no evidence of a chromosome abnormality in this syndrome, but review of the family history suggests it may be a familial disease. The mode of transmission, however, is uncertain.

Noonan 1968

1985 – Opitz formally proposed the name “Noonan syndrome” in a paper presented top the USA Society for Paediatric Research to reduce confusion with terms such as Turner phenotype; male Turner syndrome; and female pseudo-Turner.


Associated Persons

Alternative names
  • male Turner syndrome; female pseudo-Turner
  • Noonan-Ehmke syndrome

References

eponymictionary CTA

eponymictionary

the names behind the name

British doctor currently working in Perth, Australia.  Interests include psychiatry and paediatrics

Emergency physician MA (Oxon) MBChB (Edin) FACEM FFSEM with a passion for rugby; medical history; medical education; and informatics. Asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | vocortex |

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