Noonan syndrome 1 Noonan syndrome 4 obsolete Noonan-like/multiple giant cell lesion syndrome true OBSOLETE. Noonan-like/multiple giant cell lesion syndrome (NS/MGCLS) is a term used to describe a subgroup of people with Noonan syndrome who also have giant cell lesions (benign tumor-like lesions that most frequently occur in the jaws but may also affect other bones or soft tissues) and resemble individuals who have cherubism. Although NS/MGCLS was once believed to be a separate condition, it is now known to bepart of the Noonan syndrome spectrum. Mutations in the PTPN11 and SOS1 genes have been associated with NS/MGCLS; however, mutations in these genes do not always cause giant cell lesions. One family with NS/MGCLS has been found to have a mutation in the PTPN11 gene butno giant cell lesions, suggesting that other genetic factors may be involved in leading to giant cell development. Multiple giant cell lesions associated with NS may resolve after puberty with variable restoration of the facial structure. OMIM:163955 NL/MGCLS MONDO:0023873