chr20-58444159-G-A

Variant names:

• chr20-58444159-G-A
• rs786205553
• NM_004738.5:c.656G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_004738.5(VAPB):​c.656G>A​(p.Gly219Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G219V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: VAPB NM_004738.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.02
• Publications: 1 publications found

Genes affected

VAPB (HGNC:12649): (VAMP associated protein B and C) The protein encoded by this gene is a type IV membrane protein found in plasma and intracellular vesicle membranes. The encoded protein is found as a homodimer and as a heterodimer with VAPA. This protein also can interact with VAMP1 and VAMP2 and may be involved in vesicle trafficking. [provided by RefSeq, Jul 2008]

VAPB Gene-Disease associations (from GenCC):

• amyotrophic lateral sclerosis type 8

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, ClinGen
• adult-onset proximal spinal muscular atrophy, autosomal dominant

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• amyotrophic lateral sclerosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004738.5. 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
	VAPB	NM_004738.5	MANE Select	c.656G>A	p.Gly219Asp	missense	Exon 6 of 6	NP_004729.1
	VAPB	NM_001195677.2		c.294G>A	p.Arg98Arg	synonymous	Exon 3 of 3	NP_001182606.1
	VAPB	NR_036633.2		n.702G>A		non_coding_transcript_exon	Exon 4 of 4

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	VAPB	ENST00000475243.6	TSL:1 MANE Select	c.656G>A	p.Gly219Asp	missense	Exon 6 of 6	ENSP00000417175.1
	VAPB	ENST00000395802.7	TSL:1	c.294G>A	p.Arg98Arg	synonymous	Exon 3 of 3	ENSP00000379147.3
	VAPB	ENST00000903510.1		c.716G>A	p.Gly239Asp	missense	Exon 7 of 7	ENSP00000573569.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251492 AF XY: 0.00000736

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: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461894 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

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

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112012

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

⚠️ 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 Cov.: 32

Alfa AF: 0.00000438 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.28
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.38	T
Eigen	Pathogenic	0.77
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.90	D
M_CAP	Uncertain	0.11	D
MetaRNN	Uncertain	0.74	D
MetaSVM	Uncertain	-0.22	T
PhyloP100		9.0
PrimateAI	Uncertain	0.58	T
PROVEAN	Uncertain	-2.5	D
REVEL	Uncertain	0.41
Sift	Benign	0.34	T
Sift4G	Benign	0.22	T
Polyphen		1.0	D
Vest4		0.82
MutPred		0.20		Loss of catalytic residue at G219 (P = 0.0029)
MVP		0.85
MPC		1.5
ClinPred		0.98	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.44
gMVP		0.50
Mutation Taster		=9/91	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs786205553; hg19: chr20-57019215;