rs371996957

Variant names:

• chr11-44126895-T-A
• rs371996957
• NM_207122.2:c.1019T>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PP3_Strong

The NM_207122.2(EXT2):​c.1019T>A​(p.Val340Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000958 in 1,461,884 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V340I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000096 (0 hom.)
• Consequence: EXT2 NM_207122.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts P:1 U:3
• Conservation: PhyloP100: 7.91
• Publications: 2 publications found

Genes affected

EXT2 (HGNC:3513): (exostosin glycosyltransferase 2) This gene encodes one of two glycosyltransferases involved in the chain elongation step of heparan sulfate biosynthesis. Mutations in this gene cause the type II form of multiple exostoses. Alternatively spliced transcript variants encoding different isoforms have been noted for this gene. [provided by RefSeq, Jul 2008]

EXT2 Gene-Disease associations (from GenCC):

• exostoses, multiple, type 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, ClinGen, Ambry Genetics
• seizures-scoliosis-macrocephaly syndrome

  Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• hereditary multiple osteochondromas

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.962

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_207122.2. 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
	EXT2	NM_207122.2	MANE Select	c.1019T>A	p.Val340Asp	missense	Exon 6 of 14	NP_997005.1	Q93063-1
	EXT2	NM_000401.3		c.1118T>A	p.Val373Asp	missense	Exon 6 of 14	NP_000392.3	Q93063-3
	EXT2	NM_001178083.3		c.1019T>A	p.Val340Asp	missense	Exon 6 of 15	NP_001171554.1	Q93063-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	EXT2	ENST00000533608.7	TSL:1 MANE Select	c.1019T>A	p.Val340Asp	missense	Exon 6 of 14	ENSP00000431173.2	Q93063-1
	EXT2	ENST00000358681.8	TSL:1	c.1019T>A	p.Val340Asp	missense	Exon 6 of 15	ENSP00000351509.4	Q93063-2
	EXT2	ENST00000343631.4	TSL:1	c.1019T>A	p.Val340Asp	missense	Exon 7 of 15	ENSP00000342656.3	Q93063-1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251470 AF XY: 0.00000736

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: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000958 AC: 14 AN: 1461884 Hom.: 0 Cov.: 31 AF XY: 0.0000110 AC XY: 8 AN XY: 727242

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 0.0000126 AC: 14 AN: 1112004

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000564 Hom.: 0

Bravo AF: 0.0000113

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	2	-	Exostoses, multiple, type 2 (2)
1	1	-	Seizures-scoliosis-macrocephaly syndrome (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	29
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.98	D
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.51	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.6	M
PhyloP100		7.9
PrimateAI	Uncertain	0.57	T
PROVEAN	Pathogenic	-6.0	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		0.84	P
Vest4		0.96
MVP		1.0
MPC		0.81
ClinPred		0.99	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.94
gMVP		0.97
Mutation Taster		=13/87	disease causing

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: rs371996957; hg19: chr11-44148445;