NM_030923.5:c.835G>A

Variant names:

• chr2-134456751-C-T
• rs1199922536
• NM_030923.5:c.835G>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 5P and 2B. PM1 PM2 PP2 BP4_Moderate

The NM_030923.5(TMEM163):​c.835G>A​(p.Val279Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,666 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V279A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: TMEM163 NM_030923.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.16
• Publications: 2 publications found

Genes affected

TMEM163 (HGNC:25380): (transmembrane protein 163) Predicted to enable zinc ion binding activity. Predicted to be involved in zinc ion import into synaptic vesicle. Predicted to be located in early endosome membrane. Predicted to be active in intracellular vesicle and plasma membrane. Predicted to be integral component of synaptic vesicle membrane. [provided by Alliance of Genome Resources, Apr 2022]

TMEM163 Gene-Disease associations (from GenCC):

• leukodystrophy, hypomyelinating, 25

  Inheritance: AD Classification: STRONG, MODERATE, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM1: In a chain Transmembrane protein 163 (size 288) in uniprot entity TM163_HUMAN there are 4 pathogenic changes around while only 1 benign (80%) in NM_030923.5
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 4 curated pathogenic missense variants (we use a threshold of 10). The gene has 0 curated benign missense variants. Gene score misZ: 1.7669 (below the threshold of 3.09). Trascript score misZ: 1.0332 (below the threshold of 3.09). GenCC associations: The gene is linked to leukodystrophy, hypomyelinating, 25.
• BP4: Computational evidence support a benign effect (MetaRNN=0.26097322).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TMEM163	NM_030923.5	c.835G>A	p.Val279Met	missense_variant	Exon 8 of 8	ENST00000281924.6	NP_112185.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMEM163	ENST00000281924.6	c.835G>A	p.Val279Met	missense_variant	Exon 8 of 8	1	NM_030923.5	ENSP00000281924.6
TMEM163	ENST00000467316.1	n.1269G>A		non_coding_transcript_exon_variant	Exon 2 of 2	2
TMEM163	ENST00000476823.1	n.4091G>A		non_coding_transcript_exon_variant	Exon 3 of 3	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251164 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: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461666 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727124

⚠️ 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: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.000101 AC: 4 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86180

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53334

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111966

Other (OTH) AF: 0.00 AC: 0 AN: 60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000100), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Dec 14, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.835G>A (p.V279M) alteration is located in exon 8 (coding exon 8) of the TMEM163 gene. This alteration results from a G to A substitution at nucleotide position 835, causing the valine (V) at amino acid position 279 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.33
BayesDel_addAF	Benign	-0.041	T
BayesDel_noAF	Benign	-0.13
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Benign	0.029	T
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Uncertain	0.82	D
LIST_S2	Uncertain	0.88	D
M_CAP	Benign	0.0046	T
MetaRNN	Benign	0.26	T
MetaSVM	Benign	-0.67	T
MutationAssessor	Benign	0.46	N
PhyloP100		3.2
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-0.47	N
REVEL	Benign	0.26
Sift	Uncertain	0.0030	D
Sift4G	Benign	0.13	T
Polyphen		0.85	P
Vest4		0.13
MutPred		0.32		Gain of disorder (P = 0.0595);
MVP		0.18
MPC		0.94
ClinPred		0.68	D
GERP RS		5.6
Varity_R		0.19
gMVP		0.79
Mutation Taster		=79/21	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs1199922536; hg19: chr2-135214322; COSMIC: COSV56113296; COSMIC: COSV56113296;