11-47350009-C-T

Variant names:

• chr11-47350009-C-T
• rs727503219
• NM_000256.3:c.505+5G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_000256.3(MYBPC3):​c.505+5G>A variant causes a splice region, intron change. The variant allele was found at a frequency of 0.00000071 in 1,408,188 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
• Consequence: MYBPC3 NM_000256.3 splice_region, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.14
• Publications: 2 publications found

Genes affected

MYBPC3 (HGNC:7551): (myosin binding protein C3) MYBPC3 encodes the cardiac isoform of myosin-binding protein C. Myosin-binding protein C is a myosin-associated protein found in the cross-bridge-bearing zone (C region) of A bands in striated muscle. MYBPC3 is expressed exclusively in heart muscle and is a key regulator of cardiac contraction. Mutations in this gene are a frequent cause of familial hypertrophic cardiomyopathy. [provided by RefSeq, May 2022]

MYBPC3 Gene-Disease associations (from GenCC):

• hypertrophic cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• hypertrophic cardiomyopathy 4

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
• left ventricular noncompaction 10

  Inheritance: AR, AD Classification: DEFINITIVE, MODERATE, LIMITED Submitted by: Ambry Genetics
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• atrial fibrillation

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• dilated cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYBPC3	NM_000256.3	c.505+5G>A		splice_region_variant, intron_variant	Intron 4 of 34	ENST00000545968.6	NP_000247.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYBPC3	ENST00000545968.6	c.505+5G>A		splice_region_variant, intron_variant	Intron 4 of 34	5	NM_000256.3	ENSP00000442795.1
MYBPC3	ENST00000399249.6	c.505+5G>A		splice_region_variant, intron_variant	Intron 4 of 33	5		ENSP00000382193.2
MYBPC3	ENST00000544791.1	n.505+5G>A		splice_region_variant, intron_variant	Intron 4 of 26	5		ENSP00000444259.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00 AC: 0 AN: 168380 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 7.10e-7 AC: 1 AN: 1408188 Hom.: 0 Cov.: 37 AF XY: 0.00000144 AC XY: 1 AN XY: 695510

African (AFR) AF: 0.00 AC: 0 AN: 31952

American (AMR) AF: 0.00 AC: 0 AN: 36754

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25266

East Asian (EAS) AF: 0.00 AC: 0 AN: 36274

South Asian (SAS) AF: 0.00 AC: 0 AN: 79784

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49726

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5684

European-Non Finnish (NFE) AF: 9.22e-7 AC: 1 AN: 1084384

Other (OTH) AF: 0.00 AC: 0 AN: 58364

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypertrophic cardiomyopathy Uncertain:1

Jul 31, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This variant has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 25351510). This variant is not present in population databases (gnomAD no frequency). This sequence change falls in intron 4 of the MYBPC3 gene. It does not directly change the encoded amino acid sequence of the MYBPC3 protein. It affects a nucleotide within the consensus splice site. -

Cardiovascular phenotype Uncertain:1

Dec 11, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.505+5G>A intronic variant results from a G to A substitution 5 nucleotides after coding exon 4 in the MYBPC3 gene. This alteration has been reported in a hypertrophic cardiomyopathy (HCM) cohort; however, clinical details were limited (Lopes LR et al. Heart, 2015 Feb;101:294-301). 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 and will result in the creation or strengthening of a novel splice donor site. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.19
CADD	Benign	22
DANN	Benign	0.97
PhyloP100		7.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.99
SpliceAI score (max)		0.79		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.79		Position offset: -1
DS_DL_spliceai		0.61		Position offset: 5

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

Other links and lift over

dbSNP: rs727503219; hg19: chr11-47371560;