Show pageDiscussionOld revisionsBacklinksExport to PDFBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ====== Noonan Syndrome ====== ====Main Features==== * Highly variable but most have short stature, mild intellectual disability or developmental delay and * Characteristic faces * High forehead * depressed nasal bridge * low-set posteriorly rotated ears with fleshy helices {{::noonan_syndrome.png?direct&600|}} {{::noonan_syndrome_child.png?direct&600|}} Photos from [[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1049850/pdf/jmedgene00075-0018.pdf|J Med Genet. 1987;24(1):9-13.]] ====Eye Findings==== * Refractive Errors: Myopia, hyperopia and astigmatism * Ptosis * Hypertelorism * Downslanting palpebral fissures * Epicanthal folds * Keratoconus * vivid blue or blue-green iris * Posterior embryotoxin * Cataract * Strabismus * Nystagmus * Optic nerve hypoplasia * Optic nerve coloboma ====Other Findings==== * Webbed or broad neck * Chiari Malformation * Hydrocephalus * Macrocephaly * Craniosynostosis * Sensorineural deafness * Conductive hearing loss * Giant cell tumors of the jaw * Sternal deformities * pectus carinatum of the superior sternum * pectus excavated of the inferior sternum * Cardiovascular defects * Pulmonic stenosis * hypertrophic cardiomyopathy * ASD * VSD * lymphatic dysplasia * Chyptorchidism * Infertility * Hematologic abnormalities * elevation in PT/PTT * abnormal platelets, count and function ====Etiology==== * Genetic disorder of the genes in the RAS-MAPK pathway * PTPN11 (50%) * SOS1 (13%) * RAF1 (5%) * RIT1 (5%) * others * KRAS, BRAF, LZTR1, NRAS * This pathway is important in cellular differentiation and proliferation * Autosomal dominant inheritance most commonly with 2/3 denovo * Associated with advanced paternal age ====Reference==== * [[https://doi.org/10.1007/s00431-018-3183-1| van Trier, et al. Ocular findings in NS: a retrospective cohort study of 105 patients. European Journal of Pediatrics. 2018;177(8):1293–1298]] * [[https://www.aaojournal.org/article/S0161-6420(16)30594-2/fulltext|van Trier et al. Ocular Manifestations of Noonan Syndrome: A Prospective Clinical and Genetic Study of 25 Patients. Ophthalmology.2016;123(10):2134-2146]] * [[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1049850/pdf/jmedgene00075-0018.pdf|Allanson, JE. Noonan Syndrome. J Med Genet. 1987;24(1):9-13.]] * [[https://eyewiki.aao.org/Noonan_Syndrome#Ophthalmic_presentation|eyeWiki]] {{tag>syndrome}} noonan.txt Last modified: 2022/09/25 21:25by oculoman
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