chr3-49722604-G-A

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The NM_021971.4(GMPPB):c.553C>T(p.Arg185Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,613,870 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 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

GMPPB
NM_021971.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 2.18

Variant links:

Genes affected

GMPPB (HGNC:22932): (GDP-mannose pyrophosphorylase B) This gene is thought to encode a GDP-mannose pyrophosphorylase. The encoded protein catalyzes the conversion of mannose-1-phosphate and GTP to GDP-mannose, a reaction involved in the production of N-linked oligosaccharides. Alternatively spliced transcript variants encoding distinct isoforms have been described. [provided by RefSeq, Jan 2009]

GMPPB links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.971

PP5

Variant 3-49722604-G-A is Pathogenic according to our data. Variant chr3-49722604-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 60543.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-49722604-G-A is described in Lovd as [Pathogenic]. Variant chr3-49722604-G-A is described in Lovd as [Pathogenic]. Variant chr3-49722604-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GMPPB	NM_021971.4 link	c.553C>T	p.Arg185Cys	missense_variant	Exon 5 of 9	ENST00000308388.7	NP_068806.2	Q9Y5P6-1
GMPPB	NM_013334.4 link	c.553C>T	p.Arg185Cys	missense_variant	Exon 5 of 8		NP_037466.3	Q9Y5P6-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GMPPB	ENST00000308388.7 link	c.553C>T	p.Arg185Cys	missense_variant	Exon 5 of 9	1	NM_021971.4	ENSP00000311130.6		Q9Y5P6-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152216

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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

GnomAD3 exomes

AF:

0.0000359

AC:

AN:

250734

Hom.:

AF XY:

0.0000369

AC XY:

AN XY:

135520

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000145

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000177

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000103

AC:

AN:

1461536

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

727060

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000112

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:

0.00000809

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152334

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74490

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

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:

0.0000425

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.0000330

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy

Pathogenic:2

May 23, 2017

Genetic Services Laboratory, University of Chicago

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 29, 2019

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has been previously reported as a homozygous change in 6 patients with hypotonia, muscle weakness, cataracts, and elevated serum creatine kinase (PMID: 23768512, 29054425). Functional studies have shown reduced alpha-dystroglycan glycosylation in muscle and fibroblasts of individuals with this variant (PMID: 23768512). It is present in the heterozygous state in the gnomAD population database at a frequency of 0.0036% (9/250,734) and thus is presumed to be rare. The c.553C>T (p.Arg185Cys) 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.553C>T (p.Arg185Cys) variant is classified as Pathogenic. -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A14;C3809221:Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B14;C4518000:Autosomal recessive limb-girdle muscular dystrophy type 2T

Pathogenic:2

Jan 28, 2014

UCLA Clinical Genomics Center, UCLA

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 16, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 185 of the GMPPB protein (p.Arg185Cys). This variant is present in population databases (rs397509425, gnomAD 0.01%). This missense change has been observed in individuals with clinical features of GMPPB-related conditions (PMID: 23768512, 25326637, 30684953, 32403337, 32404165). ClinVar contains an entry for this variant (Variation ID: 60543). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on GMPPB function (PMID: 23768512). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. -

Inborn genetic diseases

Pathogenic:1

Aug 07, 2017

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B14

Pathogenic:1

Jul 11, 2013

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

not provided

Pathogenic:1

Sep 27, 2022

Revvity Omics, Revvity

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2T

Pathogenic:1

Jul 11, 2013

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.51

BayesDel_addAF

Uncertain

0.025

BayesDel_noAF

Uncertain

0.050

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.86

D;.;D

Eigen

Uncertain

0.55

Eigen_PC

Uncertain

0.46

FATHMM_MKL

Uncertain

0.90

LIST_S2

Pathogenic

1.0

.;D;D

M_CAP

Pathogenic

0.50

MetaRNN

Pathogenic

0.97

D;D;D

MetaSVM

Uncertain

0.25

MutationAssessor

Pathogenic

3.1

M;M;M

PrimateAI

Uncertain

0.56

PROVEAN

Pathogenic

-7.1

D;D;D

REVEL

Pathogenic

0.67

Sift

Uncertain

0.0020

D;D;D

Sift4G

Uncertain

0.027

D;D;D

Polyphen

1.0

D;D;D

Vest4

0.95

MutPred

0.59

Loss of solvent accessibility (P = 0.0299);Loss of solvent accessibility (P = 0.0299);Loss of solvent accessibility (P = 0.0299);

MVP

0.92

MPC

1.7

ClinPred

0.89

GERP RS

3.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.80

gMVP

0.81

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

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