Description
The RRAS c.259C>G (p.Gln87Glu) variant, to our knowledge, has not been reported in the medical literature and is absent from the general population (gnomAD v.2.1.1), indicating it is not a common variant. This variant occurs in the Switch II domain, critical for GTP binding, that is considered a region across RASopathy genes that is enriched for pathogenic variation and depleted of variation in gnomAD (Perviewer; PĂ©rez-Palma E et al., PMID: 31871067). This variant changes a polar glutamine to a negatively charged glutamic acid, and computational predictors indicate that the variant is damaging, evidence that correlates with impact to RRAS function. Another variant in this codon, RRAS p.Gln87Leu, was detected in the somatic sample of an individual with juvenile myelomonocytic leukemia but the variant was not detected in the germline (Flex E et al., PMID: 24705357). Variants in analogous resides in other RASopathy genes (RRAS2, MRAS) have been detected in individuals affected with Noonan syndrome and are considered pathogenic (Suzuki H et al., PMID: 31173466; Niihori T et al., PMID: 31130285). However, due to limited information, the clinical significance of this variant is uncertain.
# | Sample | Method | Observation |
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Origin | Affected | Number tested | Tissue | Purpose | Method | Individuals | Allele frequency | Families | Co-occurrences |
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1 | germline | unknown | not provided | not provided | not provided | | not provided | not provided | not provided | not provided |