12 prepubertal children with Noonan syndrome due to mutations in the PTPN11 gene [7 males, 6 females; median age, years: 8.6 (range 5.1-13.4)] were studied; 12 prepubertal children with short stature (SS) [7 males, 5 females; median age, years: 8.1 (range 4.8-13.1)] served as the control group.
In our total cohort, patients with NS and a PTPN11 mutation presented significantly higher prevalence of short stature (p = 0.03) and pulmonary valve stenosis (p = 0.01), and lower prevalence of hypertrophic cardiomyopathy (p = 0.01).
The degree of short stature does not associate closely with the presence of a mutation; however, some PTPN11-positive patients have decreased growth hormone (GH)-dependent growth factors consistent with mild GH insensitivity.
We conclude that each mutation contributed independently to individual features in the ocular and cardiovascular systems, although short stature was more significantly influenced by the p.Y279C change in PTPN11 rather than the mutation in FBN1.
The degree of short stature in children does not associate closely with the presence of mutations, however some PTPN11-positive patients have decreased GH-dependent growth factors consistent with mild GH insensitivity.
Germline mutations in PTPN11--the gene encoding the nonreceptor protein tyrosine phosphatase SHP-2--represent a major cause of Noonan syndrome (NS), a developmental disorder characterized by short stature and facial dysmorphism, as well as skeletal, hematologic, and congenital heart defects.