rs397509422

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PM5PP3_Moderate

The NM_021971.4(GMPPB):​c.1000G>C​(p.Asp334His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,416 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging 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. D334N) 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

12
6
1

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 7.81

Publications

13 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr3-49721835-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 60540.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.877

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GMPPBNM_021971.4 linkc.1000G>C p.Asp334His missense_variant Exon 9 of 9 ENST00000308388.7 NP_068806.2
GMPPBNM_013334.4 linkc.1081G>C p.Asp361His missense_variant Exon 8 of 8 NP_037466.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GMPPBENST00000308388.7 linkc.1000G>C p.Asp334His missense_variant Exon 9 of 9 1 NM_021971.4 ENSP00000311130.6

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251044
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461416
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
727068
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53006
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111954
Other (OTH)
AF:
0.00
AC:
0
AN:
60390
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.80
BayesDel_addAF
Pathogenic
0.26
D
BayesDel_noAF
Pathogenic
0.22
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.75
D;.;D
Eigen
Pathogenic
0.95
Eigen_PC
Pathogenic
0.87
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.97
.;D;D
M_CAP
Pathogenic
0.43
D
MetaRNN
Pathogenic
0.88
D;D;D
MetaSVM
Uncertain
0.66
D
MutationAssessor
Pathogenic
4.0
H;.;H
PhyloP100
7.8
PrimateAI
Pathogenic
0.87
D
PROVEAN
Pathogenic
-6.6
D;D;D
REVEL
Pathogenic
0.77
Sift
Uncertain
0.0010
D;D;D
Sift4G
Uncertain
0.0090
D;D;D
Polyphen
1.0
D;D;D
Vest4
0.81
MutPred
0.56
Loss of sheet (P = 0.0357);.;Loss of sheet (P = 0.0357);
MVP
0.94
MPC
1.6
ClinPred
1.0
D
GERP RS
5.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.3
Varity_R
0.83
gMVP
0.94
Mutation Taster
=3/97
disease causing

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

Other links and lift over

dbSNP: rs397509422; hg19: chr3-49759268; API