rs104894532

Variant names:

• chr16-8797908-G-A
• rs104894532
• NM_000303.3:c.26G>A

Your query was ambiguous. Multiple possible variants found:

• chr16-8797908-G-A
• chr16-8797908-G-C
• chr16-8797908-G-T

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000303.3(PMM2):​c.26G>A​(p.Cys9Tyr) variant causes a missense change. The variant allele was found at a frequency of 0.00000206 in 1,458,958 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C9F) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: PMM2 NM_000303.3 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 6.86
• Publications: 15 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: G2P, Labcorp Genetics (formerly Invitae), Orphanet, PanelApp Australia, ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 19 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 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 chr16-8797908-G-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2429015.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, 0.966
• PP5: Variant 16-8797908-G-A is Pathogenic according to our data. Variant chr16-8797908-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 7720.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PMM2	NM_000303.3	c.26G>A	p.Cys9Tyr	missense_variant	Exon 1 of 8	ENST00000268261.9	NP_000294.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PMM2	ENST00000268261.9	c.26G>A	p.Cys9Tyr	missense_variant	Exon 1 of 8	1	NM_000303.3	ENSP00000268261.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000415 AC: 1 AN: 241228 AF XY: 0.00000760

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000919

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1458958 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 725624

African (AFR) AF: 0.00 AC: 0 AN: 33456

American (AMR) AF: 0.00 AC: 0 AN: 44430

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26046

East Asian (EAS) AF: 0.00 AC: 0 AN: 39620

South Asian (SAS) AF: 0.00 AC: 0 AN: 85720

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52594

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111158

Other (OTH) AF: 0.00 AC: 0 AN: 60172

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000277 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

PMM2-congenital disorder of glycosylation Pathogenic:5

Aug 01, 2000

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Jul 22, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects PMM2 function (PMID: 10922383, 11715002). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt PMM2 protein function. ClinVar contains an entry for this variant (Variation ID: 7720). This missense change has been observed in individual(s) with congenital disorder of glycosylation type 1a (PMID: 10922383, 11715002). 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 (rs104894532, gnomAD 0.0009%). This sequence change replaces cysteine, which is neutral and slightly polar, with tyrosine, which is neutral and polar, at codon 9 of the PMM2 protein (p.Cys9Tyr). -

Aug 27, 2014

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Apr 23, 2018

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: PMM2 c.26G>A (p.Cys9Tyr) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was observed with an allele frequency of 4.2e-06 in 236634 control chromosomes (gnomAD and publications). The variant, c.26G>A, has been reported in the literature in multiple individuals affected with Congenital Disorder of Glycosylation Type 1a (Bjursell_2000, Vuillaumier-Barrot_2000). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in 30%-50% of normal activity. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as pathogenic. -

Aug 12, 2022

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.86
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.86	D;.
Eigen	Uncertain	0.46
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.93	D;D
M_CAP	Uncertain	0.21	D
MetaRNN	Pathogenic	0.97	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.3	M;.
PhyloP100		6.9
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-5.5	D;D
REVEL	Pathogenic	0.89
Sift	Uncertain	0.0020	D;D
Sift4G	Uncertain	0.0030	D;D
Polyphen		0.37	B;.
Vest4		0.87
MutPred		0.88		Loss of catalytic residue at L10 (P = 0.0407);Loss of catalytic residue at L10 (P = 0.0407);
MVP		0.99
MPC		0.0087
ClinPred		0.99	D
GERP RS		4.8
PromoterAI		0.011	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.95
gMVP		0.93
Mutation Taster		=6/94	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs104894532; hg19: chr16-8891765;