Noonan's syndrome

A complex familial syndrome similar to Turner’s, with the Turner phenotype, but there is no chromosomal defect and Noonan syndrome occurs in both sexes. Clinical features are short stature, low-set ears and many minor skeletal deformities of which the commonest are pectus excavatum and cubitus valgus. Intelligence often below average, but the majority of Noonan children complete elementary school with satisfying results. Cardiac abnormalities occur in 50% of patients: these include pulmonary valve stenosis, thick and dysplastic pulmonary valves, right heart anomalies and left ventricular cardiomyopathy. Relatively frequent occurrence, 1: 1000. Inheritance is autosomal dominant. Sporadic occurrence is believed to be caused by new mutations. In her paper of 1968 Noonan wrote that in more thorough investigations, one or both parents frequently showed one or more characteristics. For a family in which a child with Noonan’s syndrome has been born, but both parents lack signs of it, the risk for the next child is about 5 percent.

Jacquline A. Noonan and Dorothy Ehmke [American cardiologist/paediatrician] in 1963 defined the syndrome on the basis of clinical and cytogenetic findings in six boys and three girls with valvular pulmonary stenosis, short stature, hypertelorism and skeletal anomalies, and, in boys, retentio testis. In a later publication (1968) Noonan described a total of 19 patients of both sexes with unusual facies, congenital heart defect and other symptoms resembling those of Turner’s syndrome. However, the patients had normal chromosomes.

While at Iowa, Noonan, together with Dorothy Ehmke, conducted a clinical investigation, which included 833 children with congenital heart disease who were carefully studied for the presence of additional extra-cardiac anomalies. Nine of these children had a similar characteristic facies and pulmonary stenosis. These patients were reported by Noonan to the Midwest Society of Pediatric Research held in Cincinnati in 1962.

The term Noonan’s syndrome was suggested as early as in 1965 by the human geneticist John Marius Opitz (born 1935) and his colleagues when they presented a paper at the Society for Pediatric Research. The eponymic term was first used in the same issue of American Journal of Diseases of Children (1968) where Noonan’s article appeared, and it was firmly established in 1971 at the fourth conference on the clinical delineation of birth defects, Baltimore, where several papers on Noonan syndrome were presented. In about 1972 it was entered in McKusick's book of inherited disorders.

During the course of Noonan's investigations in Iowa, John Opitz was a medical student and first year resident in the Department of Pediatrics. Subsequently, he went to Madison, Wisconsin, where he noted a number of other patients who were similar to those described by Noonan. These individuals had small stature, hypertelorism, mild mental retardation and often ptosis and skeletal abnormalities, as well as 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,

An early description of the Noonan syndrome is credited to Koblinsky (1883), a medical student at the Russian/Estonian University of Dorpat; Opitz and Philip D. Pallister republished the original illustration of this patient in 1979. The phenotype had also been documented by Weissenberg in 1928. In a historical review of the Noonan syndrome, Cole (1980) suggested that the blacksmith depicted in Albright's painting Among Those Left might have had the disorder.

Turner’s syndrome, or chromosome XO syndrome, is entered as Morgagni-Turner-Albright syndrome, under Giovanni Battista Morgagni, Italian anatomist and pathologist, 1682-1771.

• O. Koblinsky:
  Ueber eine flughautähnliche Ausbreitung am Halse.
  Archiv für Anthropologie, Braunschweig, 1883, 14: 343.
• S. Weissenberg:
  Eine eigentümliche Hautfaltenbildung am Halse. Anthropol Anz, 1928, 5: 141-144.
• J. A. Noonan, D.A. Ehmke:
  Associated noncardiac malformations in children with congenital heart disease.
  [Abstract] Journal of Pediatrics, St. Louis, 1963, 63: 468-470.
• J. A. Noonan:
  Hypertelorism with Turner phenotype. A new syndrome with associated congenital heart disease. American Journal of Diseases of Children, Chicago, 1968, 116: 373-380.
• J. M. Opitz, P. D. Pallister:
  Brief historical note: the concept of gonadal dysgenesis.
  American Journal of Medical Genetics, New York, 1979, 4: 333-343.
• R. B. Cole:
  Noonan's Syndrome. A Historical Perspective.
  Pediatrics, Evanston, Illinois, 1980, 66: 468-469.
• H. M. M. Mendez, J. M. Opitz:
  Noonan syndrome: a review.
  American Journal of Medical Genetics, New York, 1985, 21: 493-506.
• J. M. Opitz:
  The Noonan syndrome (editorial).
  American Journal of Medical Genetics, New York, 1985, 21: 515-518.