rs199922550

Variant names:

• chr3-49721847-C-T
• rs199922550
• NM_021971.4:c.988G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PP3 PP5_Very_Strong

The NM_021971.4(GMPPB):​c.988G>A​(p.Val330Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000101 in 1,613,684 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V330A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00011 (0 hom.)
• Consequence: GMPPB NM_021971.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 7.81
• Publications: 10 publications found

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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.795
• PP5: Variant 3-49721847-C-T is Pathogenic according to our data. Variant chr3-49721847-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 60547.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_021971.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GMPPB	NM_021971.4	MANE Select	c.988G>A	p.Val330Ile	missense	Exon 9 of 9	NP_068806.2
	GMPPB	NM_013334.4		c.1069G>A	p.Val357Ile	missense	Exon 8 of 8	NP_037466.3

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GMPPB	ENST00000308388.7	TSL:1 MANE Select	c.988G>A	p.Val330Ile	missense	Exon 9 of 9	ENSP00000311130.6
	GMPPB	ENST00000495627.2	TSL:2	c.1096G>A	p.Val366Ile	missense	Exon 9 of 9	ENSP00000503768.1
	GMPPB	ENST00000308375.10	TSL:2	c.1069G>A	p.Val357Ile	missense	Exon 8 of 8	ENSP00000309092.6

Frequencies

GnomAD3 genomes AF: 0.0000460 AC: 7 AN: 152224 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

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: 0.0000735

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000597 AC: 15 AN: 251166 AF XY: 0.0000442

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000968

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.000107 AC: 156 AN: 1461460 Hom.: 0 Cov.: 32 AF XY: 0.0000894 AC XY: 65 AN XY: 727074

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.0000447 AC: 2 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53146

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.000132 AC: 147 AN: 1111882

Other (OTH) AF: 0.0000828 AC: 5 AN: 60384

GnomAD4 genome AF: 0.0000460 AC: 7 AN: 152224 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74362

African (AFR) AF: 0.0000241 AC: 1 AN: 41458

American (AMR) AF: 0.0000654 AC: 1 AN: 15282

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5198

South Asian (SAS) AF: 0.00 AC: 0 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000735 AC: 5 AN: 68042

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.0000545 Hom.: 0

Bravo AF: 0.0000264

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.000259 AC: 1

ExAC AF: 0.0000741 AC: 9

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.0000545

EpiControl AF: 0.000119

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
3	-	-	not provided (3)
2	-	-	Autosomal recessive limb-girdle muscular dystrophy type 2T (2)
1	-	-	Inborn genetic diseases (1)
1	-	-	Muscular dystrophy-dystroglycanopathy (1)
1	-	-	Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A14 (1)
1	-	-	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 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.31
BayesDel_addAF	Benign	0.0050	T
BayesDel_noAF	Uncertain	-0.030
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.42	T
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.76	D
MetaRNN	Pathogenic	0.80	D
MetaSVM	Uncertain	0.77	D
MutationAssessor	Pathogenic	4.2	H
PhyloP100		7.8
PrimateAI	Uncertain	0.66	T
PROVEAN	Benign	-0.98	N
REVEL	Uncertain	0.60
Sift	Benign	0.032	D
Sift4G	Uncertain	0.037	D
Polyphen		0.99	D
Vest4		0.89
MVP		0.92
MPC		1.4
ClinPred		0.97	D
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.3
Varity_R		0.22
gMVP		0.93
Mutation Taster		=8/92	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs199922550; hg19: chr3-49759280; COSMIC: COSV57540715; COSMIC: COSV57540715;