| domain | MRAS-specific established finding | evidence type/source | certainty or key limitation |
|---|---|---|---|
| Disease identity | Noonan syndrome 11 is the MRAS-related Noonan syndrome entity; key identifiers include OMIM 618499 and MONDO:0032786 | Aggregated disease-gene resource plus literature-linked target-disease evidence (pqac-00000010) | High confidence for disease-gene mapping; sparse primary patient literature compared with other Noonan genes |
| Causal gene | The causal gene is **MRAS** (muscle RAS oncogene homolog), encoding the RAS-family small GTPase M-Ras | Human gene-disease association evidence and primary case reports (pqac-00000010, pqac-00000000) | High confidence |
| Reported pathogenic variants | Reported NS11 missense activating variants include **p.Gly23Val**, **p.Thr68Ile**, and **p.Gln71Arg** | Human case report and mechanistic/structural studies referencing NS variants (pqac-00000000, pqac-00000006, pqac-00000009) | p.Gly23Val and p.Thr68Ile are directly documented in the 2017 human report; p.Gln71Arg is strongly supported by later mechanistic literature but was not detailed in the retrieved human case excerpt |
| Inheritance | Reported human cases were **de novo**; disease mechanism is consistent with **autosomal dominant** transmission if inherited | Human trio/genotype-negative cohort evidence (pqac-00000000, pqac-00000001, pqac-00000004) | Very small number of directly retrieved patients limits penetrance/segregation estimates |
| Molecular effect | NS11 is caused by **germline activating missense variants** producing **gain-of-function/constitutive activation** of MRAS | Human functional studies and structural/biochemical studies (pqac-00000000, pqac-00000006, pqac-00000008, pqac-00000009) | High confidence for GOF mechanism |
| Core phenotype | Phenotype is dominated by **congenital or early-onset cardiac hypertrophy/HCM**, often with additional congenital heart disease, plus classic Noonan features such as distinctive facies, short stature, hypotonia/developmental delay, and learning difficulties | Direct human clinical evidence from reported patients (pqac-00000000, pqac-00000001, pqac-00000002, pqac-00000004) | High confidence that cardiac disease is prominent; exact frequency estimates remain uncertain because very few cases are available |
| Cardiac manifestations | Reported findings include **biventricular/left ventricular hypertrophy**, **outflow tract obstruction**, **pulmonary valve stenosis**, and **atrial septal defect**; one patient required **surgical myectomy** in childhood | Direct human clinical case data (pqac-00000002, pqac-00000003, pqac-00000004) | Strong case-level evidence, but no MRAS-specific natural-history cohort |
| Development/growth | Reported non-cardiac findings include **short stature**, **global developmental delay**, **delayed walking/language**, **intellectual/learning difficulties**, **joint hypermobility**, **pectus excavatum**, **hypotonia**, and characteristic facies | Direct human clinical evidence (pqac-00000001, pqac-00000002, pqac-00000005) | Frequencies cannot be robustly estimated from retrieved data |
| Signaling mechanism | Pathogenic MRAS variants enhance formation/function of the **SHOC2-MRAS-PP1C** holophosphatase complex, promoting **RAF inhibitory-site (S259/CR2-pS) dephosphorylation**, RAF activation, and downstream **ERK/MAPK** signaling | Biochemical, structural, and cell-based mechanistic evidence (pqac-00000006, pqac-00000008, pqac-00000009) | High mechanistic confidence; much evidence derives from in vitro/structural systems rather than patient tissue |
| Diagnostic approach | Diagnosis is established by **sequencing-based molecular testing**: WES/trio analysis identified one de novo case, and targeted sequencing of genotype-negative RASopathy patients with cardiac hypertrophy found another | Human diagnostic evidence (pqac-00000000, pqac-00000002, pqac-00000004) | High confidence that MRAS should be included in RASopathy/HCM genomic testing; no MRAS-specific biomarker beyond genotype |
| Population frequency | Reported pathogenic variants are **ultra-rare/absent in population databases**; one 2017 report noted absence from >280,000 gnomAD alleles | Human genetic case evidence (pqac-00000002) | Variant-level rarity supported; disease prevalence/incidence for MRAS-NS11 specifically is not established |
| Epidemiology | **No established MRAS-specific prevalence, incidence, sex ratio, founder effect, anticipation, or mosaicism data** were identified in retrieved evidence | Evidence-gap assessment from available literature context (pqac-00000000, pqac-00000004) | Major limitation: ultra-rare condition with only a handful of published cases in retrieved sources |
| Treatment | **No established MRAS-specific targeted therapy** has been proven in clinical practice; current care is syndrome-/phenotype-directed, especially cardiac management | Human case outcomes plus general RASopathy management context (pqac-00000002, pqac-00000011) | Important limitation: treatment evidence is extrapolated largely from broader RASopathy/Noonan care, not MRAS-only cohorts |
| Trial landscape | **MEKinRAS (NCT06555237)** is a recruiting phase 2 trial of **trametinib** for RASopathy-associated HCM, but the registry does **not explicitly state MRAS-related NS11-specific eligibility or enrollment** | ClinicalTrials.gov registry evidence (pqac-00000012) | Potential relevance to MRAS-HCM is indirect; not an MRAS-specific interventional study |
| Evidence base overall | The MRAS-specific evidence base remains **small but coherent**: rare de novo activating missense variants, recurrent severe cardiac phenotype, and a convergent SHOC2-MRAS-PP1C/RAF-ERK mechanism | Integrated human genetic, functional, structural, and registry evidence (pqac-00000000, pqac-00000004, pqac-00000006, pqac-00000009, pqac-00000012) | Main limitation is very limited patient count and lack of MRAS-specific long-term outcome studies |


*Table: This table summarizes the compact, MRAS-specific evidence base for Noonan syndrome 11, emphasizing what is directly established versus what remains uncertain. It is useful for separating firm gene/mechanism/phenotype findings from gaps in prevalence and treatment data.*