1-155140045-C-A

Position:

• chr1-155140045-C-A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_153741.2(DPM3):​c.196G>T​(p.Asp66Tyr) variant causes a missense change. The variant allele was found at a frequency of 0.00000657 in 152,222 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
• Consequence: DPM3 NM_153741.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.91

Genes affected

DPM3 (HGNC:3007): (dolichyl-phosphate mannosyltransferase subunit 3, regulatory) Dolichol-phosphate mannose (Dol-P-Man) serves as a donor of mannosyl residues on the lumenal side of the endoplasmic reticulum (ER). Lack of Dol-P-Man results in defective surface expression of GPI-anchored proteins. Dol-P-Man is synthesized from GDP-mannose and dolichol-phosphate on the cytosolic side of the ER by the enzyme dolichyl-phosphate mannosyltransferase. The protein encoded by this gene is a subunit of dolichyl-phosphate mannosyltransferase and acts as a stabilizer subunit of the dolichyl-phosphate mannosyltransferase complex. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a chain Dolichol-phosphate mannosyltransferase subunit 3 (size 91) in uniprot entity DPM3_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_153741.2
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.98

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DPM3	NM_153741.2	c.196G>T	p.Asp66Tyr	missense_variant	2/2	ENST00000368400.5	NP_714963.1
DPM3	NM_018973.4	c.286G>T	p.Asp96Tyr	missense_variant	1/1		NP_061846.2
DPM3	XM_017001498.2	c.196G>T	p.Asp66Tyr	missense_variant	2/2		XP_016856987.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DPM3	ENST00000368400.5	c.196G>T	p.Asp66Tyr	missense_variant	2/2	1	NM_153741.2	ENSP00000357385	P1
DPM3	ENST00000368399.1	c.286G>T	p.Asp96Tyr	missense_variant	1/1			ENSP00000357384
DPM3	ENST00000341298.3	c.196G>T	p.Asp66Tyr	missense_variant	2/2	2		ENSP00000344338	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152222 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152222 Hom.: 0 Cov.: 31 AF XY: 0.0000134 AC XY: 1 AN XY: 74360

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

DPM3-congenital disorder of glycosylation Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 19, 2020

This sequence change replaces aspartic acid with tyrosine at codon 66 of the DPM3 protein (p.Asp66Tyr). The aspartic acid residue is highly conserved and there is a large physicochemical difference between aspartic acid and tyrosine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with DPM3-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.60
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	.;D;D
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D;.;D
M_CAP	Uncertain	0.27	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Uncertain	0.58	D
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-7.5	D;D;D
REVEL	Pathogenic	0.89
Sift	Uncertain	0.0010	D;D;D
Sift4G	Uncertain	0.0030	D;D;D
Polyphen		1.0	.;D;D
Vest4		0.92
MutPred		0.90		.;Loss of disorder (P = 0.0546);Loss of disorder (P = 0.0546);
MVP		0.96
MPC		1.1
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.96
gMVP		0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1204451277; hg19: chr1-155112521;