01 January 2001
Noonan and Ehmke (1963) were the first to report the syndrome called later Noonan syndrome. The incidence in the general population is estimated to be about 1 in 1000 and 1 in 2000 live births.
The main features are short stature, a short neck with webbing or redundant nuchal skin, cardiac anomalies particularly dysplastic pulmonary valve with PS, ASD, VSD, PDA and hypertrophic cardiomyopathy, a characteristic chest deformity with a pectus carinatum superiorly and a pectus excavatum inferiorly, widespaced nipples, undescended testes in males and umbilical hernia. The undescended testes were thought to have contributed to delayed puberty and oligozoospermia. Keratosis pilaris atrophicans has been reported in classic cases of Noonan syndrome (Pierini and Pieini, 1979). The chromosomes are normal.Some present with conductive and sensorineural deafness and developmental delay, usually mild, was reported in in 35% of cases. The average birth length is 47 cm and the childhood growth tend to parallel the 3rd centle with poor growth spurt during puberty. The average adult height in males is 162.5 cm and 152.7 cm in females.
The facial features changes with time. In the newborn period the main features are hypertelorism, a downward eyeslant, low-set posteriorly rotated ears, a deeply grooved philtrum and a broad nasal tip.
In later infancy the facies can become coarser but in adults may be more subtle. Feeding difficulties are present in about 75%. Hypertrophic cardiomyopathy can be progressive and may not be present at birth (Wilmshurst and Katritsis, 1996).
A bleeding diathesis can be part of the condition and is mainly due to coagulation factors dysfunction (Sharland et al.,1992) and platelet abnormalities. Cardio-facio-cutaneous (CFC) syndrome (qv) may be the severe end of the spectrum of this syndrome.
Title: Genetic counselling in Noonan syndrome
Author: Sharland M, Morgan M, Smith G, et al.
Journal: Am J Med Genet; 45:437-440
Title: Coagulation-factor deficiencies and abnormal bleeding in Noonan's syndrome
Author: Sharland M, Patton MA, Talbot S, et al.
Title: Restrictive and hypertrophic cardiomyopathies in Noonan syndrome: the overlap syndromes
Author: Wilmshurst PT, Katritsis D
Journal: Br Heart J;75:94-97
Title: Keratosis pilaris atrophicans faciei (ulerythema ophryogenes): a cutaneous marker in the Noonan syndrome
Author: Pierini DO, Pierini AM
Journal: Br J Dermatol;100:409-416.
Title: Cardiologic abnormalities in Noonan syndrome: phenotypic diagnosis and echocardiographic assessment of 118
Author: Burch M, Sharland M, Shinebourne E, et al.
Journal: J Am Coll Cardiol;22:1189-1192.
Title: Association of congenital heart disease with syndromes or other defects
Author: Noonan JA
Journal: Pediatr Clin N Am;25:797-816
Title: Prenatal diagnosis of Noonan's syndrome in a female infant with spontaneous resolution of cystic hygroma and
Author: Izquierdo L, Kushnir O, Sanchez D, Curet L, Olney P, Sarto GE, Clericuzio C, Olney R
Journal: West J Med Apr;152(4):418-21
Title: Posterior nuchal cystic hygroma
Author: Edwards MJ, Graham JM Jr
Journal: Clin Perinatol Sep;17(3):611-40
Title: Prenatal sonographic documentation of cystic hygroma regression in Noonan syndrome.
Author: Donnenfeld AE, Nazir MA, Sindoni F, Librizzi RJ
Journal: Am J Med Genet Jun 15;39(4):461-5
Title: Intrauterine diagnosis and evolution of a cardiomyopathy in a fetus with Noonan's syndrome.
Author: Sonesson SE, Fouron JC, Lessard M
Journal: Acta Paediatr Apr;81(4):368-70
Title: Multiple-marker screen positive results in Noonan syndrome
Author: Aranguren G, Garcia-Minaur S, Loridan L, Uribarren A, Martin Vargas L, Rodriguez-Soriano J
Journal: Prenat Diagn Feb;16(2):183-4.