dbSNP rs749730219: GMPPB:p.Arg243Pro (chr3-49722271-C-G) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM2PM5BP4_Moderate

The NM_021971.4(GMPPB):c.728G>C(p.Arg243Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,536 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R243W) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

GMPPB
NM_021971.4 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 2.08

Publications

0 publications found

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 Gene-Disease associations (from GenCC):

muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A14
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
myopathy caused by variation in GMPPB
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
autosomal recessive limb-girdle muscular dystrophy type 2T
Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Orphanet, PanelApp Australia
congenital myasthenic syndrome
Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
congenital muscular dystrophy with cerebellar involvement
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
congenital muscular dystrophy with intellectual disability
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
congenital myasthenic syndromes with glycosylation defect
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
muscle-eye-brain disease
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

GMPPB links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr3-49722272-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 835761.

BP4

Computational evidence support a benign effect (MetaRNN=0.2587614).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GMPPB	NM_021971.4 link	c.728G>C	p.Arg243Pro	missense_variant	Exon 7 of 9	ENST00000308388.7	NP_068806.2
GMPPB	NM_013334.4 link	c.728G>C	p.Arg243Pro	missense_variant	Exon 7 of 8		NP_037466.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GMPPB	ENST00000308388.7 link	c.728G>C	p.Arg243Pro	missense_variant	Exon 7 of 9	1	NM_021971.4	ENSP00000311130.6

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461536

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727072

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44718

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86238

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53226

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111892

Other (OTH)

AF:

0.0000166

AC:

AN:

60384

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.34

BayesDel_addAF

Benign

-0.011

BayesDel_noAF

Benign

-0.25

CADD

Benign

(source)

DANN

Benign

0.89

DEOGEN2

Benign

0.36

T;.;T

Eigen

Benign

-0.63

Eigen_PC

Benign

-0.60

FATHMM_MKL

Uncertain

0.94

LIST_S2

Benign

0.0

.;D;D

M_CAP

Uncertain

0.095

MetaRNN

Benign

0.26

T;T;T

MetaSVM

Benign

-0.84

MutationAssessor

Benign

1.5

L;L;L

PhyloP100

2.1

PrimateAI

Benign

0.25

PROVEAN

Benign

-1.7

N;N;N

REVEL

Benign

0.14

Sift

Benign

0.14

T;T;T

Sift4G

Benign

0.34

T;T;T

Vest4

0.34

ClinPred

0.19

GERP RS

1.7

Varity_R

0.33

gMVP

0.87

Mutation Taster

=60/40

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over