Noonan syndrome is an autosomal dominant disease resulting from mutations in the ras-associated mitogen activating protein kinase pathway involved in signal transduction associated with cell proliferation, differentiation, life, and metabolism.
A girl from non-consanguineous family was referred to pediatric endocrine department because of short stature. The 15-year-old girl was born with weight 2300 g by caesarean section and was followed due to pulmonary valve stenosis and mitral insufficiency in the pediatric cardiology department; she underwent cardiac surgery during the infant period. On physical examination height was 131.6 cm (<3 p), height SDS -4.73, weight 28.7 kg (<3 p), weight SDS -5.31, target height 150.65, and target height SDS was 1.95. Physical examination also revealed dysmorphic facial appearance with webbed neck, hypertelorism, epicanthus, downward palpebral fissures, low-set ears rotated backward, triangular face, micrognathia, high-arched palate, widely spaced nipples, cardiac operation scar, and pectus excavatum. Full blood count, biochemical analysis, and thyroid function tests were found to be normal in terms of short stature.
Since the dysmorphic features were consistent with Noonan syndrome, p.D61G heterozygote mutation in PTPN11 gene was found. The patient with Noonan syndrome was started treatment with 45 micrograms/kg/dose of growth hormone because of short stature and insufficient height velocity.
In this report, Noonan syndrome patient associated with heterozygous P.D61G mutation was presented. Early diagnosis and appropriate treatment will prevent the development of complications.