RNA-sequencing reveals genes with abnormal expression in RAF1 mutant iPSC-derived cardiomyocytes and identifies subsets of genes dysregulated by aberrant MEK1/2 or ERK5 pathways that could contribute to the NS-associated HCM.
Cardiofaciocutaneous syndrome (CFCS) is a rare developmental disorder that is phenotypically similar to Noonan syndrome and is associated with mutations in BRAF, MEK1, MEK2, and KRAS.
Taken together, our findings demonstrate that mutations in MAP2K1, which are frequently associated with neurological complications and intellectual disability, can be associated with a milder clinical and neurocognitive profile more typical of individuals with Noonan syndrome.
Taken together, our findings demonstrate that mutations in MAP2K1, which are frequently associated with neurological complications and intellectual disability, can be associated with a milder clinical and neurocognitive profile more typical of individuals with Noonan syndrome.
Expression of the mutant RASA2, MAP2K1, or RIT1 alleles in heterologous cells increased RAS-ERK pathway activation, supporting a causative role in NS pathogenesis.
Expression of the mutant RASA2, MAP2K1, or RIT1 alleles in heterologous cells increased RAS-ERK pathway activation, supporting a causative role in NS pathogenesis.
PTPN11 (39.0%), SOS1 (20.3%), RAF1 (6.8%), KRAS (5.1%), and BRAF (1.7%) mutations were identified in NS; BRAF (41.2%), SHOC2 (23.5%), and MEK1 (5.9%) mutations in cardiofaciocutaneous syndrome; and HRAS and PTPN11 mutations in Costello syndrome and LEOPARD syndrome, respectively.
In conclusion, the present results exclude copy number variation of PTPN11, SOS1, RAF1, KRAS, BRAF, MEK1 and MEK2 as a common pathogenic mechanism of NS.
Cardio-facio-cutaneous and Noonan syndromes due to mutations in the RAS/MAPK signalling pathway: genotype-phenotype relationships and overlap with Costello syndrome.
Cardio-facio-cutaneous and Noonan syndromes due to mutations in the RAS/MAPK signalling pathway: genotype-phenotype relationships and overlap with Costello syndrome.
Cardio-facio-cutaneous and Noonan syndromes due to mutations in the RAS/MAPK signalling pathway: genotype-phenotype relationships and overlap with Costello syndrome.
Here, we report that 18 of 231 individuals with Noonan syndrome without known mutations (corresponding to 3% of all affected individuals) and two of six individuals with LEOPARD syndrome without PTPN11 mutations have missense mutations in RAF1, which encodes a serine-threonine kinase that activates MEK1 and MEK2.