Gene Validity Curation

Gene Validity Classification Summary

Gene/Disease Pair:

KRAS : Costello syndrome

HGNC:6407 | MONDO_0009026
Mode of Inheritance: Autosomal dominant inheritance (HP:0000006)
Expert Panel: RASopathy EP
SOP: Gene Clinical Validity Standard Operating Procedures (SOP), Version 5
Genetic Evidence
Case-Level Data
 Evidence Type Case Information Type Guidelines Points PMIDs/Notes
Default Range Max Total Counted
Variant Evidence
 Autosomal Dominant or X-linked Disorder Variant is de novo 2 0-3 12
0
0
Zenker M et al. 2007 Feb (PMID:17056636); Carta C et al. 2006 Jul (PMID:16773572);
Proband with predicted or proven null variant 1.5 0-2 10
Proband with other variant type with some evidence of gene impact 0.5 0-1.5 7
0
0
Bertola DR et al. 2007 Apr 28 (PMID:17468812);
Autosomal Recessive Disease Two variants in trans and at least one de novo or a predicted/proven null variant 2 0-3 12
Two variants (not predicted/proven null) with some evidence of gene impact in trans 1 0-1.5
Segregation Evidence Evidence of segregation in one or more families   Sequencing Method 0-3 3
 
Total LOD Score Canditate Gene Sequencing Exome/Genome or all genes sequenced in linkage region  
2-2.99 0.5 1
3-4.99 1 2
≥5 1.5 3
Case-Control Data
 Case-Control Study Type Case-Control Quality Criteria Guidelines Points PMIDs/Notes
Points/Study Max Total Counted
Single Variant Analysis 1. Variant Detection Methodology
2. Power
3. Bias and confounding
4. Statistical Significance		 0-6 12
Aggregate Variant Analysis 0-6
Total Genetic Evidence Points (Maximum 12) 0
Experimental Evidence
 Evidence Category Evidence Type Guidelines Points PMIDs/Notes
Default Range Max Total Counted
Function Biochemical Function 0.5 0 - 2 2
Protein Interaction 0.5 0 - 2
Expression 0.5 0 - 2
Functional Alteration Patient cells 1 0 - 2 2
Non-patient cells 0.5 0 - 1
Models Non-human model organism 2 0 - 4 4
Cell culture model 1 0 - 2
Rescue Rescue in human 2 0 - 4
Rescue in non-human model organism 2 0 - 4
Rescue in cell culture model 1 0 - 2
Rescue in patient cells 1 0 - 2
Total Experimental Evidence Points (Maximum 6) 0

 

 

Assertion criteria Genetic Evidence (0-12 points) Experimental Evidence
(0-6 points)		 Total Points
(0-18) 		Replication Over Time (Y/N)
Description Case-level, family segregation, or case-control data that support the gene-disease association Gene-level experimental evidence that support the gene-disease association Sum of Genetic & Experimental
Evidence 		> 2 pubs w/ convincing evidence over time (>3 yrs)
Assigned Points 0 0 0 NO
CALCULATED CLASSIFICATION LIMITED 1-6
MODERATE 7-11
STRONG 12-18
DEFINITIVE 12-18 AND replication over time
Valid contradictory evidence (Y/N)*
NO
CALCULATED CLASSIFICATION (DATE)
No Classification
07/24/2018
MODIFY CALCULATED CLASSIFICATION
YES
MODIFIED CLASSIFICATION (DATE)
Disputed
07/24/2018
REASON(S) FOR CHANGE
no score-able cases
EXPERT CURATION (DATE)
Disputed
07/24/2018
EVIDENCE SUMMARY
There have been five studies to date that have identified patients with features consistent with Costello syndrome (CS) and de novo or inherited variants in KRAS (Carta et al., 2006; Nava et al., 2007; Schubbert et al., 2007; Zenker et al., 2007). However, none of the patients possessed features to definitively differentiate their diagnosis from other RASopathies as CS. Variable expressivity, age of ascertainment, and outdated clinical assessments of affected individuals may complicate the clinical diagnosis of CS versus severe forms of CFC. Therefore, the evidence for this association is Disputed. Furthermore, the HRAS gene is believed to be the only gene associated with CS (Aoki et al., 2005; Estep, Tidyman, Teitell, Cotter, & Rauen, 2006; Gripp et al., 2006; Kerr et al., 2006; Zampino et al., 2007).