chr3-49722971-C-T

Position:

chr3-49722971-C-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PM2PP5_Moderate

The NM_021971.4(GMPPB):c.402+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,613,222 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

GMPPB
NM_021971.4 splice_donor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 7.64

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:

GMPPB (HGNC:):

GMPPB links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 3-49722971-C-T is Pathogenic according to our data. Variant chr3-49722971-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 570106.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr3-49722971-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GMPPB	NM_021971.4 linkuse as main transcript	c.402+1G>A		splice_donor_variant, intron_variant		ENST00000308388.7	NP_068806.2	Q9Y5P6-1
GMPPB	NM_013334.4 linkuse as main transcript	c.402+1G>A		splice_donor_variant, intron_variant			NP_037466.3	Q9Y5P6-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GMPPB	ENST00000308388.7 linkuse as main transcript	c.402+1G>A		splice_donor_variant, intron_variant		1	NM_021971.4	ENSP00000311130.6		Q9Y5P6-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152188

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000479

AC:

AN:

1461034

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

726856

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000630

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152188

Hom.:

Cov.:

AF XY:

0.0000135

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:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000103

Hom.:

Bravo

AF:

0.0000151

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

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:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 10, 2023

For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 570106). Disruption of this splice site has been observed in individual(s) with clinical features of GMPPB-associated conditions (PMID: 26310427; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is present in population databases (rs145564018, gnomAD 0.007%). This sequence change affects a donor splice site in intron 4 of the GMPPB gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in GMPPB are known to be pathogenic (PMID: 23768512, 26310427). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.62

BayesDel_noAF

Pathogenic

0.27

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.91

FATHMM_MKL

Pathogenic

0.98

GERP RS

5.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

2.7

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

1.0

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.46

Position offset: -11

DS_DL_spliceai

1.0

Position offset: 1

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