16-8813090-G-T

Variant names:

• chr16-8813090-G-T
• rs398123309
• NM_000303.3:c.623G>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP2 PP3_Strong

The NM_000303.3(PMM2):​c.623G>T​(p.Gly208Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic 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. G208A) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: PMM2 NM_000303.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.48
• Publications: 6 publications found

Genes affected

PMM2 (HGNC:9115): (phosphomannomutase 2) The protein encoded by this gene catalyzes the isomerization of mannose 6-phosphate to mannose 1-phosphate, which is a precursor to GDP-mannose necessary for the synthesis of dolichol-P-oligosaccharides. Mutations in this gene have been shown to cause defects in glycoprotein biosynthesis, which manifests as carbohydrate-deficient glycoprotein syndrome type I. [provided by RefSeq, Jul 2008]

PMM2 Gene-Disease associations (from GenCC):

• congenital disorder of glycosylation type I

  Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
• PMM2-congenital disorder of glycosylation

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, ClinGen, Labcorp Genetics (formerly Invitae)
• hyperinsulinemic hypoglycemia with polycystic kidney disease

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 11 uncertain in NM_000303.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-8813090-G-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 92804.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 89 curated pathogenic missense variants (we use a threshold of 10). The gene has 24 curated benign missense variants. Gene score misZ: -1.3872 (below the threshold of 3.09). Trascript score misZ: -1.8083 (below the threshold of 3.09). GenCC associations: The gene is linked to PMM2-congenital disorder of glycosylation, congenital disorder of glycosylation type I.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000303.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PMM2	NM_000303.3	MANE Select	c.623G>T	p.Gly208Val	missense	Exon 7 of 8	NP_000294.1	A0A0S2Z4J6

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PMM2	ENST00000268261.9	TSL:1 MANE Select	c.623G>T	p.Gly208Val	missense	Exon 7 of 8	ENSP00000268261.4	O15305-1
	PMM2	ENST00000565221.5	TSL:1	n.*241G>T		non_coding_transcript_exon	Exon 5 of 6	ENSP00000457932.1	H3BV34
	PMM2	ENST00000566540.5	TSL:1	n.*245G>T		non_coding_transcript_exon	Exon 5 of 6	ENSP00000454284.1	H3BM92

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1445402 Hom.: 0 Cov.: 27 AF XY: 0.00 AC XY: 0 AN XY: 720378

African (AFR) AF: 0.00 AC: 0 AN: 33186

American (AMR) AF: 0.00 AC: 0 AN: 44706

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26020

East Asian (EAS) AF: 0.00 AC: 0 AN: 39634

South Asian (SAS) AF: 0.00 AC: 0 AN: 85876

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5732

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1096976

Other (OTH) AF: 0.00 AC: 0 AN: 59854

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	D
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.83	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.88	D
MutationAssessor	Pathogenic	4.1	H
PhyloP100		9.5
PrimateAI	Uncertain	0.72	T
PROVEAN	Pathogenic	-8.7	D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.92		Gain of catalytic residue at G208 (P = 0.0271)
MVP		0.97
MPC		0.045
ClinPred		1.0	D
GERP RS		4.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.99
gMVP		0.99
Mutation Taster		=2/98	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs398123309; hg19: chr16-8906947;