6-31536684-C-A

Position:

• chr6-31536684-C-A

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_004640.7(DDX39B):​c.433-1G>T variant causes a splice acceptor, intron change. 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 Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: DDX39B NM_004640.7 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.55

Genes affected

DDX39B (HGNC:13917): (DExD-box helicase 39B) This gene encodes a member of the DEAD box family of RNA-dependent ATPases that mediate ATP hydrolysis during pre-mRNA splicing. The encoded protein is an essential splicing factor required for association of U2 small nuclear ribonucleoprotein with pre-mRNA, and it also plays an important role in mRNA export from the nucleus to the cytoplasm. This gene belongs to a cluster of genes localized in the vicinity of the genes encoding tumor necrosis factor alpha and tumor necrosis factor beta. These genes are all within the human major histocompatibility complex class III region. Mutations in this gene may be associated with rheumatoid arthritis. Alternative splicing results in multiple transcript variants. Related pseudogenes have been identified on both chromosomes 6 and 11. Read-through transcription also occurs between this gene and the upstream ATP6V1G2 (ATPase, H+ transporting, lysosomal 13kDa, V1 subunit G2) gene. [provided by RefSeq, Feb 2011]

ATP6V1G2-DDX39B (HGNC:41999): (ATP6V1G2-DDX39B readthrough (NMD candidate)) This locus represents naturally occurring read-through transcription between the neighboring ATP6V1G2 (ATPase, H+ transporting, lysosomal 13kDa, V1 subunit G2) and DDX39B (DEAD box polypeptide 39B) genes located in the major histocompatibility complex class III region of chromosome 6. The read-through transcript and is a candidate for nonsense-mediated mRNA decay (NMD), and is thus unlikely to produce a protein product. [provided by RefSeq, Feb 2011]

DDX39B (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 5.1, offset of -23, new splice context is: tttccttcctctgttttgAGact. Cryptic site results in frameshift 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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DDX39B	NM_004640.7	c.433-1G>T		splice_acceptor_variant, intron_variant		ENST00000396172.6	NP_004631.1
DDX39B	NM_080598.6	c.433-1G>T		splice_acceptor_variant, intron_variant			NP_542165.1
DDX39B	NR_037852.2	n.398-1G>T		splice_acceptor_variant, intron_variant
ATP6V1G2-DDX39B	NR_037853.1	n.1236-1G>T		splice_acceptor_variant, intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DDX39B	ENST00000396172.6	c.433-1G>T		splice_acceptor_variant, intron_variant		1	NM_004640.7	ENSP00000379475.1
ATP6V1G2-DDX39B	ENST00000376185.5	n.*647-1G>T		splice_acceptor_variant, intron_variant		2		ENSP00000365356.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Neurodevelopmental disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Undiagnosed Rare Disease Clinic, Indiana University School of Medicine

Mar 01, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	36
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.98	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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_AG_spliceai		0.91		Position offset: -37
DS_AL_spliceai		0.99		Position offset: -1

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr6-31504461;