20-50935209-A-G

Variant names:

• chr20-50935209-A-G
• rs775589720
• NM_003859.3:c.706T>C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_003859.3(DPM1):​c.706T>C​(p.Tyr236His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000617 in 1,458,864 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: DPM1 NM_003859.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 8.71

Genes affected

DPM1 (HGNC:3005): (dolichyl-phosphate mannosyltransferase subunit 1, catalytic) 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. Human DPM1 lacks a carboxy-terminal transmembrane domain and signal sequence and is regulated by DPM2. Mutations in this gene are associated with congenital disorder of glycosylation type Ie. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2015]

ADNP-AS1 (HGNC:51227): (ADNP antisense RNA 1)

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DPM1	NM_003859.3	c.706T>C	p.Tyr236His	missense_variant	Exon 9 of 9	ENST00000371588.10	NP_003850.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DPM1	ENST00000371588.10	c.706T>C	p.Tyr236His	missense_variant	Exon 9 of 9	1	NM_003859.3	ENSP00000360644.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251052 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135716

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000617 AC: 9 AN: 1458864 Hom.: 0 Cov.: 28 AF XY: 0.00000413 AC XY: 3 AN XY: 725976

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000721

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

Alfa AF: 0.000111 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Jun 16, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.706T>C (p.Y236H) alteration is located in exon 9 (coding exon 9) of the DPM1 gene. This alteration results from a T to C substitution at nucleotide position 706, causing the tyrosine (Y) at amino acid position 236 to be replaced by a histidine (H). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Congenital disorder of glycosylation type 1E Uncertain:1

May 15, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant  is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 1433475). This variant has not been reported in the literature in individuals affected with DPM1-related conditions. This variant is present in population databases (rs775589720, gnomAD no frequency). This sequence change replaces tyrosine, which is neutral and polar, with histidine, which is basic and polar, at codon 236 of the DPM1 protein (p.Tyr236His). 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	Uncertain	0.45
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.13
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.60	D;T
Eigen	Uncertain	0.35
Eigen_PC	Uncertain	0.36
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Benign	0.054	D
MetaRNN	Uncertain	0.64	D;D
MetaSVM	Benign	-0.69	T
MutationAssessor	Benign	1.8	L;.
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-4.5	D;D
REVEL	Uncertain	0.53
Sift	Benign	0.037	D;D
Sift4G	Benign	0.099	T;T
Polyphen		0.73	P;.
Vest4		0.71
MutPred		0.54		Gain of disorder (P = 0.0144);.;
MVP		0.79
MPC		0.40
ClinPred		0.79	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.1
Varity_R		0.43
gMVP		0.80

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: rs775589720; hg19: chr20-49551746;