NM_001308142.2:c.693+1G>T

Variant names:

• chr16-14218999-G-T
• rs1464308161
• NM_001308142.2:c.693+1G>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_001308142.2(MRTFB):​c.693+1G>T variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.00000125 in 1,598,328 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: MRTFB NM_001308142.2 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.23
• Publications: 0 publications found

Genes affected

MRTFB (HGNC:29819): (myocardin related transcription factor B) Enables transcription coactivator activity. Involved in positive regulation of pri-miRNA transcription by RNA polymerase II and positive regulation of striated muscle tissue development. Predicted to be located in cytoplasm. Predicted to be active in nucleus. [provided by Alliance of Genome Resources, Apr 2022]

MRTFB Gene-Disease associations (from GenCC):

• neurodevelopmental disorder

  Inheritance: AD Classification: LIMITED Submitted by: G2P

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.054242425 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.2, offset of -45, new splice context is: aaaGTtagt. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001308142.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MRTFB	NM_001308142.2	MANE Select	c.693+1G>T		splice_donor intron	N/A	NP_001295071.1	Q9ULH7-5
	MRTFB	NM_001365411.2		c.660+1G>T		splice_donor intron	N/A	NP_001352340.1	Q9ULH7-1
	MRTFB	NM_001365412.2		c.693+1G>T		splice_donor intron	N/A	NP_001352341.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MRTFB	ENST00000571589.6	TSL:2 MANE Select	c.693+1G>T		splice_donor intron	N/A	ENSP00000459626.2	Q9ULH7-5
	MRTFB	ENST00000574045.5	TSL:1	c.693+1G>T		splice_donor intron	N/A	ENSP00000459205.1	Q9ULH7-4
	MRTFB	ENST00000573051.1	TSL:1	c.540+1G>T		splice_donor intron	N/A	ENSP00000460589.1	Q9ULH7-2

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151992 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.000288

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.91e-7 AC: 1 AN: 1446336 Hom.: 0 Cov.: 30 AF XY: 0.00000139 AC XY: 1 AN XY: 717406

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000304 AC: 1 AN: 32932

American (AMR) AF: 0.00 AC: 0 AN: 42760

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25808

East Asian (EAS) AF: 0.00 AC: 0 AN: 39298

South Asian (SAS) AF: 0.00 AC: 0 AN: 83616

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53268

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5692

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1103228

Other (OTH) AF: 0.00 AC: 0 AN: 59734

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151992 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74220

African (AFR) AF: 0.00 AC: 0 AN: 41370

American (AMR) AF: 0.00 AC: 0 AN: 15266

Ashkenazi Jewish (ASJ) AF: 0.000288 AC: 1 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5188

South Asian (SAS) AF: 0.00 AC: 0 AN: 4812

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10578

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67994

Other (OTH) AF: 0.00 AC: 0 AN: 2086

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		6.2
GERP RS		5.6

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.97		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.20		Position offset: -46
DS_DL_spliceai		0.97		Position offset: -1

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

Other links and lift over

dbSNP: rs1464308161; hg19: chr16-14312856;