9-127935748-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_003863.4(DPM2):c.229A>G(p.Lys77Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: DPM2 NM_003863.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.714

Genes affected

DPM2 (HGNC:3006): (dolichyl-phosphate mannosyltransferase subunit 2, 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 hydrophobic protein that contains 2 predicted transmembrane domains and a putative ER localization signal near the C terminus. This protein associates with DPM1 in vivo and is required for the ER localization and stable expression of DPM1 and also enhances the binding of dolichol-phosphate to DPM1. [provided by RefSeq, Jul 2008]

(HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3341748).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DPM2	NM_003863.4	c.229A>G	p.Lys77Glu	missense_variant	4/4	ENST00000314392.13
DPM2	NM_001378437.1	c.139A>G	p.Lys47Glu	missense_variant	3/3
DPM2	NR_165631.1	n.386A>G		non_coding_transcript_exon_variant	4/4
DPM2	NR_165632.1	n.70A>G		non_coding_transcript_exon_variant	2/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DPM2	ENST00000314392.13	c.229A>G	p.Lys77Glu	missense_variant	4/4	1	NM_003863.4	P1
	ENST00000592240.5	n.143+1103T>C		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital muscular dystrophy with intellectual disability and severe epilepsy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 26, 2019

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The glutamic acid amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with DPM2-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces lysine with glutamic acid at codon 77 of the DPM2 protein (p.Lys77Glu). The lysine residue is weakly conserved and there is a small physicochemical difference between lysine and glutamic acid. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.085
BayesDel_addAF	Benign	-0.22	T
BayesDel_noAF	Benign	-0.55
Cadd	Benign	15
Dann	Benign	0.68
DEOGEN2	Benign	0.13	T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.31	N
LIST_S2	Benign	0.41	T
M_CAP	Benign	0.016	T
MetaRNN	Benign	0.33	T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.28	T
PROVEAN	Benign	-0.91	N
REVEL	Benign	0.091
Sift	Benign	0.40	T
Sift4G	Benign	0.14	T
Polyphen		0.0070	B
Vest4		0.034
MutPred		0.56		Loss of MoRF binding (P = 8e-04);
MVP		0.38
MPC		0.86
ClinPred		0.032	T
GERP RS		-2.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.067
gMVP		0.28

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

Publications

LitVar

Other links and lift over

dbSNP: rs1831494309; hg19: chr9-130698027;