rs398124146
Variant summary
Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PM2PP2PP3_StrongPP5_Very_Strong
The NM_004380.3(CREBBP):c.4336C>T(p.Arg1446Cys) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_004380.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 15 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
CREBBP | NM_004380.3 | c.4336C>T | p.Arg1446Cys | missense_variant | Exon 26 of 31 | ENST00000262367.10 | NP_004371.2 |
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 30
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Rubinstein-Taybi syndrome due to CREBBP mutations Pathogenic:2
Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with Menke-Hennekam syndrome 1 (MIM#618332) and Rubinstein-Taybi syndrome 1 (MIM#180849). (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from arginine to cysteine. (I) 0254 - This variant is suspected mosaic. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0602 - Variant is located in a hotspot region or cluster of pathogenic variants in the histone acetylation protein domain (DECIPHER). (SP) 0704 - Another missense variant comparable to the one identified in this case has limited previous evidence for pathogenicity. p.(Arg1446His) has been observed in an internal VCGS patient with features consistent with Rubinstein-Taybi syndrome and was classified as likely pathogenic. Additional changes to leucine and glycine are reported, but neither in the germline context (ClinVar). (SP) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been classified as likely pathogenic and pathogenic in ClinVar by clinical laboratories who observed the variant as de novo. This variant was also classified as a VUS by another clinical laboratory in ClinVar. (SP) 1002 - This variant has moderate functional evidence supporting abnormal protein function. Transfected cell lines with this variant showed reduced acetyltransferase activity (PMID: 28970362). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Variant summary: CREBBP c.4336C>T (p.Arg1446Cys) results in a non-conservative amino acid change located in the CBP/p300-type histone acetyltransferase domain (IPR031162) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251384 control chromosomes (gnomAD). c.4336C>T has been reported in the literature as a somatic mutation in multiple individuals affected with a variety of tumor phenotypes. These reports do not provide unequivocal conclusions about association of the variant with Rubinstein-Taybi Syndrome. However, this variant was previously observed at our laboratory as a de-novo variant in a fetal exome case presenting with increased NT, IUGR, polydactyly, small cerebellum and cardiac anamolies. In addition, one other ClinVar submitter (evaluation after 2014) classified the variant as Likely Pathogenic, citing a de-novo occurrence observed in a sample submitted to their laboratory. These findings suggest a de-novo etiology for disease. At least one publication reports in-vitro experimental evidence showing that the R1446C variant confers a loss-of-function as indicated by reduced acetyltransferase activity in bladder cancer and HEK293 cell lines (e.g. Duex_2018). Based on the evidence outlined above, the variant was classified as pathogenic. -
Rubinstein-Taybi syndrome Pathogenic:1
This sequence change replaces arginine with cysteine at codon 1446 of the CREBBP protein (p.Arg1446Cys). The arginine residue is highly conserved and there is a large physicochemical difference between arginine and cysteine. This variant is not present in population databases (ExAC no frequency). This variant has been reported to be de novo in an individual affected with polysyndactyly, hirsutism, and clitoromegaly (Invitae). ClinVar contains an entry for this variant (Variation ID: 95047). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
not provided Uncertain:1
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Neoplasm Other:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at