rs761364688

Positions:

• chr11-44109209-GAATCAC-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PM4 PP3 PP5

The NM_207122.2(EXT2):​c.553_558delAATCAC​(p.Asn185_His186del) variant causes a conservative inframe deletion change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: EXT2 NM_207122.2 conservative_inframe_deletion
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 9.20

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 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_207122.2.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP
• PP5: Variant 11-44109209-GAATCAC-G is Pathogenic according to our data. Variant chr11-44109209-GAATCAC-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 534136.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
EXT2	NM_207122.2	c.553_558delAATCAC	p.Asn185_His186del	conservative_inframe_deletion	3/14	ENST00000533608.7	NP_997005.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
EXT2	ENST00000533608.7	c.553_558delAATCAC	p.Asn185_His186del	conservative_inframe_deletion	3/14	1	NM_207122.2	ENSP00000431173.2

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jun 22, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In-frame deletion of 2 amino acids in a non-repeat region; In silico analysis supports a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Exostoses, multiple, type 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 24, 2017

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Experimental studies and prediction algorithms are not available for this variant, and the functional significance of the deleted amino acids is currently unknown. This variant has not been reported in the literature in individuals with EXT2-related disease. This variant is present in population databases (rs761364688, ExAC 0.001%). This variant, c.553_558delAATCAC, results in the deletion of 2 amino acids of the EXT2 protein (p.Asn185_His186del), but otherwise preserves the integrity of the reading frame. -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs761364688; hg19: chr11-44130759;