Noonan syndrome (NS) is a genetic disorder caused by germline mutations in RAS/MAPK pathway. Predisposition to juvenile myelomonocytic leukemia-like myeloproliferative disorder is well known. Only rare cases of isolated neonatal thrombocytopenia in patients with NS have been described. We report an unusual case of patient with NS and neonatal presentation of severe thrombocytopenia, consistent with diagnosis of congenital amegakaryocytic thrombocytopenia (CAMT) but without MPL (thrombopoietin

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... ceptor) gene mutation, who developed bone marrow failure at the age of 4 months. A review of the literature identified four patients with NS and isolated thrombocytopenia but no other case of infant bone marrow failure was previously described. We think that CAMT like clinical picture is rare but nonrandom observation in NS patients with risk of development of bone marrow failure.