12-56172427-C-A

Position:

• chr12-56172427-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The NM_001330288.2(SMARCC2):​c.1926+1G>T variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SMARCC2 NM_001330288.2 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1 O:1
• Conservation: PhyloP100: 7.27

Genes affected

SMARCC2 (HGNC:11105): (SWI/SNF related, matrix associated, actin dependent regulator of chromatin subfamily c member 2) The protein encoded by this gene is a member of the SWI/SNF family of proteins, whose members display helicase and ATPase activities and which are thought to regulate transcription of certain genes by altering the chromatin structure around those genes. The encoded protein is part of the large ATP-dependent chromatin remodeling complex SNF/SWI and contains a predicted leucine zipper motif typical of many transcription factors. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

(HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.01658641 fraction of the gene. Cryptic splice site detected, with MaxEntScore 8.4, offset of -38, new splice context is: ctcGTgagt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 12-56172427-C-A is Pathogenic according to our data. Variant chr12-56172427-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 522824.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, not_provided=1, Uncertain_significance=1}. Variant chr12-56172427-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SMARCC2	NM_001330288.2	c.1926+1G>T		splice_donor_variant		ENST00000550164.6	NP_001317217.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SMARCC2	ENST00000550164.6	c.1926+1G>T		splice_donor_variant		5	NM_001330288.2	ENSP00000449396	A2
	ENST00000553176.1	n.213-9878G>T		intron_variant, non_coding_transcript_variant		2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1413812 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 699312

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

SMARCC2-related BAFopathy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Jun 10, 2021

- -

SMARCC2-related disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Undiagnosed Diseases Network, NIH

May 10, 2017

This individual has been reported in PMID: 30580808 (individual 8). -

Coffin-Siris syndrome 8 Other:1

not provided, no classification provided

literature only

GeneReviews

-

Recurrent de novo splicing variant; affected persons have developmental delays, minimal or absent speech, and hypotonia. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Pathogenic	33
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	D;D;D;D
GERP RS		4.3
RBP_binding_hub_radar		1.1
RBP_regulation_power_radar		2.8

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.20		Position offset: 39
DS_DL_spliceai		0.99		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555221275; hg19: chr12-56566211;