Abstract Background Noonan and Noonan-like syndromes are multisystem genetic disorders. mainly with autosomal dominant trasmission. caused by mutations in several genes. Missense pathogenetic variants of SOS1 gene are the second most common cause of Noonan syndrome (NS) and account approximately for 13% to 17% of cases. https://www.pipingrockers.shop/product-category/vitamin-a/