NM_001387283.1:c.2438+1G>C

Variant names:

• chr19-11013113-G-C
• rs1555774786
• NM_001387283.1:c.2438+1G>C

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001387283.1(SMARCA4):​c.2438+1G>C variant causes a splice donor, intron 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 Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SMARCA4 NM_001387283.1 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 10.0
• Publications: 0 publications found

Genes affected

SMARCA4 (HGNC:11100): (SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 4) The protein encoded by this gene is a member of the SWI/SNF family of proteins and is similar to the brahma protein of Drosophila. Members of this family have helicase and ATPase activities and 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, which is required for transcriptional activation of genes normally repressed by chromatin. In addition, this protein can bind BRCA1, as well as regulate the expression of the tumorigenic protein CD44. Mutations in this gene cause rhabdoid tumor predisposition syndrome type 2. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2012]

SMARCA4 Gene-Disease associations (from GenCC):

• Coffin-Siris syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet, Illumina
• intellectual disability, autosomal dominant 16

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• rhabdoid tumor predisposition syndrome 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P
• uterine corpus sarcoma

  Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
• familial rhabdoid tumor

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hereditary nonpolyposis colon cancer

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ENSG00000266936 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-11013113-G-C is Pathogenic according to our data. Variant chr19-11013113-G-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2452865.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001387283.1. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMARCA4	NM_001387283.1	MANE Plus Clinical	c.2438+1G>C		splice_donor intron	N/A	NP_001374212.1
	SMARCA4	NM_003072.5	MANE Select	c.2438+1G>C		splice_donor intron	N/A	NP_003063.2
	SMARCA4	NM_001128849.3		c.2438+1G>C		splice_donor intron	N/A	NP_001122321.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMARCA4	ENST00000646693.2	MANE Plus Clinical	c.2438+1G>C		splice_donor intron	N/A	ENSP00000495368.1
	SMARCA4	ENST00000344626.10	TSL:1 MANE Select	c.2438+1G>C		splice_donor intron	N/A	ENSP00000343896.4
	SMARCA4	ENST00000643549.1		c.2438+1G>C		splice_donor intron	N/A	ENSP00000493975.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1

Mar 13, 2024

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2438+1G>C intronic variant results from a G to C substitution one nucleotide after coding exon 15 of the SMARCA4 gene. Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site; however, direct evidence is insufficient at this time (Ambry internal data). Loss-of-function variants in SMARCA4 are known to cause rhabdoid tumor predisposition syndrome including small cell carcinoma of the ovary-hypercalcemic type (SCCOHT); however, such associations with neurodevelopmental disorders are exceedingly rare (Kosho T et al. Am J Med Genet C Semin Med Genet. 2014 Sep;166C(3):262-75; Jelinic P et al. Nat Genet. 2014 May;46(5):424-6). Based on the supporting evidence, this alteration is likely pathogenic for rhabdoid tumor predisposition syndrome; however, the association of this alteration with Coffin-Siris syndrome is unknown.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	34
DANN	Uncertain	0.99
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		10
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DL_spliceai		1.0		Position offset: -1

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

Other links and lift over

dbSNP: rs1555774786; hg19: chr19-11123789;