16-8847735-C-A

Position:

• chr16-8847735-C-A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000303.3(PMM2):​c.651C>A​(p.Asp217Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,796 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 Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: PMM2 NM_000303.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.33

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]

(HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a chain Phosphomannomutase 2 (size 244) in uniprot entity PMM2_HUMAN there are 79 pathogenic changes around while only 2 benign (98%) in NM_000303.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PMM2	NM_000303.3	c.651C>A	p.Asp217Glu	missense_variant	8/8	ENST00000268261.9	NP_000294.1
PMM2	XM_047434215.1	c.402C>A	p.Asp134Glu	missense_variant	6/6		XP_047290171.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PMM2	ENST00000268261.9	c.651C>A	p.Asp217Glu	missense_variant	8/8	1	NM_000303.3	ENSP00000268261	P1
	ENST00000567942.1	n.345G>T		non_coding_transcript_exon_variant	2/2	3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460796 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726762

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

PMM2-congenital disorder of glycosylation Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Counsyl

Feb 15, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D;D;.
Eigen	Pathogenic	0.71
Eigen_PC	Uncertain	0.64
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Pathogenic	1.0	D;D;D
M_CAP	Pathogenic	0.52	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.1	.;H;.
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.60	T
PROVEAN	Uncertain	-3.8	D;D;D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	.;D;.
Vest4		0.97
MutPred		0.96		.;Gain of disorder (P = 0.148);.;
MVP		0.98
MPC		0.012
ClinPred		1.0	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.95
gMVP		0.98

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

Publications

LitVar

Other links and lift over

dbSNP: rs752614554; hg19: chr16-8941592;