16-8813090-G-C

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong

The NM_000303.3(PMM2):c.623G>C(p.Gly208Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000876 in 1,597,560 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 Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000090 ( 0 hom. )

Consequence

PMM2
NM_000303.3 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 9.48

Variant links:

Genes affected

PMM2 (HGNC:9115): (phosphomannomutase 2) The protein encoded by this gene catalyzes the isomerization of mannose 6-phosphate to mannose 1-phosphate, which is a precursor to GDP-mannose necessary for the synthesis of dolichol-P-oligosaccharides. Mutations in this gene have been shown to cause defects in glycoprotein biosynthesis, which manifests as carbohydrate-deficient glycoprotein syndrome type I. [provided by RefSeq, Jul 2008]

PMM2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PM1

In a chain Phosphomannomutase 2 (size 244) in uniprot entity PMM2_HUMAN there are 79 pathogenic changes around while only 2 benign (98%) in NM_000303.3

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.994

PP5

Variant 16-8813090-G-C is Pathogenic according to our data. Variant chr16-8813090-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 92804.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-8813090-G-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PMM2	NM_000303.3 link	c.623G>C	p.Gly208Ala	missense_variant	Exon 7 of 8	ENST00000268261.9	NP_000294.1	O15305-1A0A0S2Z4J6Q59F02
PMM2	XM_047434215.1 link	c.374G>C	p.Gly125Ala	missense_variant	Exon 5 of 6		XP_047290171.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PMM2	ENST00000268261.9 link	c.623G>C	p.Gly208Ala	missense_variant	Exon 7 of 8	1	NM_000303.3	ENSP00000268261.4		O15305-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152158

Hom.:

Cov.:

show subpopulations

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

AF:

0.00000899

AC:

AN:

1445402

Hom.:

Cov.:

AF XY:

0.00000416

AC XY:

AN XY:

720378

show subpopulations

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:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000912

Gnomad4 OTH exome

AF:

0.0000334

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152158

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74344

show subpopulations

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

Alfa

AF:

0.0000557

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

PMM2-congenital disorder of glycosylation

Pathogenic:7

Jul 17, 2023

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with congenital disorder of glycosylation, type Ia (MIM#212065). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0115 - Variants in this gene are known to have variable expressivity. The clinical manifestations and course are highly variable, ranging from infants who pass away in the first year of life to mildly affected adults (PMID: 20301289). (I) 0200 - Variant is predicted to result in a missense amino acid change from glycine to alanine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v3) <0.01 for a recessive condition (1 heterozygote, 0 homozygotes). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v2) (1 heterozygote, 0 homozygotes). (I) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0600 - Variant is located in the annotated eukaryotic phosphomannomutase domain (DECIPHER). (I) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been classified as likely pathogenic and pathogenic by multiple clinical laboratories in ClinVar, and has been observed in individuals with CDG who also had another PMM2 variant, three of whom were known to be compound heterozygous (PMIDs: 22649348, 10801058, 28122681, 30397276). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Aug 13, 2018

Rady Children's Institute for Genomic Medicine, Rady Children's Hospital San Diego

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has been previously reported in the compound heterozygous state in individuals with Congenital disorder of glycosylation Type 1A (PMID: 9497260, 19396570, 10801058) and has been classified as pathogenic and likely pathogenic by multiple clinical diagnostic laboratories in ClinVar (Variation ID: 92804). It is absent from the ExAC and gnomAD population databases and thus is presumed to be rare. The c.623G>C (p.Gly208Ala) variant affects a highly conserved amino acid and is predicted by multiple in silico tools to have a deleterious effect on protein function. Based on the available evidence, the c.623G>C (p.Gly208Ala) variant is classified as Likely Pathogenic. -

May 16, 2016

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: The PMM2 c.623G>C (p.Gly208Ala) variant involves the alteration of a conserved nucleotide. 5/5 in silico tools predict a damaging outcome. This variant was found in 1/121408 control chromosomes at a frequency of 0.0000082, which does not exceed the estimated maximal expected allele frequency of a pathogenic PMM2 variant (0.005902). This variant has been reported in multiple CDG1A patients homozygously or as a compound heterozygotes with a pathogenic variant (such as R141H) in trans. All reported patients had very low level of PMM activity detected. In addition, one clinical diagnostic laboratory classified this variant as pathogenic. Considering all, this variant is classified as pathogenic. -

Dec 24, 2023

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 16, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Feb 24, 2017

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 14, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 208 of the PMM2 protein (p.Gly208Ala). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with PMM2-CDG (PMID: 9497260, 10801058, 15277997, 24037084). ClinVar contains an entry for this variant (Variation ID: 92804). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt PMM2 protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

not provided

Pathogenic:1

Feb 05, 2013

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.97

BayesDel_addAF

Pathogenic

0.58

BayesDel_noAF

Pathogenic

0.60

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.94

D;D;.

Eigen

Pathogenic

0.92

Eigen_PC

Pathogenic

0.83

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

1.0

D;D;D

M_CAP

Pathogenic

0.79

MetaRNN

Pathogenic

0.99

D;D;D

MetaSVM

Pathogenic

0.85

MutationAssessor

Pathogenic

4.1

.;H;.

PrimateAI

Uncertain

0.71

PROVEAN

Pathogenic

-5.8

D;D;D

REVEL

Pathogenic

0.98

Sift

Pathogenic

0.0

D;D;D

Sift4G

Uncertain

0.012

D;D;D

Polyphen

1.0

.;D;.

Vest4

0.99

MutPred

0.97

.;Gain of catalytic residue at G208 (P = 0.0103);.;

MVP

0.98

MPC

0.046

ClinPred

1.0

GERP RS

4.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.99

gMVP

0.98

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.050

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over