11-44108141-C-A

Position:

• chr11-44108141-C-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_207122.2(EXT2):​c.429C>A​(p.Tyr143Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: EXT2 NM_207122.2 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.02

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-44108141-C-A is Pathogenic according to our data. Variant chr11-44108141-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 465701.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr11-44108141-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
EXT2	NM_207122.2	c.429C>A	p.Tyr143Ter	stop_gained	2/14	ENST00000533608.7	NP_997005.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
EXT2	ENST00000533608.7	c.429C>A	p.Tyr143Ter	stop_gained	2/14	1	NM_207122.2	ENSP00000431173	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Exostoses, multiple, type 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 04, 2017

While this particular variant has not been reported in the literature, loss-of-function variants in EXT2 are known to be pathogenic (PMID: 19810120). This sequence change creates a premature translational stop signal at codon 143 (p.Tyr143*) of the EXT2 gene. It is expected to result in an absent or disrupted protein product. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	28
DANN	Uncertain	1.0
Eigen	Uncertain	0.26
Eigen_PC	Benign	0.061
FATHMM_MKL	Uncertain	0.93	D
MutationTaster	Benign	1.0	A;A;A;A
Vest4		0.85
GERP RS		0.23

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: rs1555002543; hg19: chr11-44129691;