chr8-117799783-G-A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 1P and 4B. PP3BS2

The NM_000127.3(EXT1):​c.2170C>T​(p.Leu724Phe) variant causes a missense change. The variant allele was found at a frequency of 0.00000479 in 1,461,892 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: 32)
Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

EXT1
NM_000127.3 missense

Scores

7
7
5

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.86
Variant links:
Genes affected
EXT1 (HGNC:3512): (exostosin glycosyltransferase 1) This gene encodes an endoplasmic reticulum-resident type II transmembrane glycosyltransferase involved in the chain elongation step of heparan sulfate biosynthesis. Mutations in this gene cause the type I form of multiple exostoses. [provided by RefSeq, Jul 2008]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.815
BS2
High AC in GnomAdExome4 at 7 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
EXT1NM_000127.3 linkuse as main transcriptc.2170C>T p.Leu724Phe missense_variant 11/11 ENST00000378204.7 NP_000118.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
EXT1ENST00000378204.7 linkuse as main transcriptc.2170C>T p.Leu724Phe missense_variant 11/111 NM_000127.3 ENSP00000367446 P1
EXT1ENST00000684189.1 linkuse as main transcriptn.1637C>T non_coding_transcript_exon_variant 11/11
EXT1ENST00000684443.1 linkuse as main transcriptn.2296C>T non_coding_transcript_exon_variant 2/2
EXT1ENST00000437196.1 linkuse as main transcript downstream_gene_variant 5 ENSP00000407299

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
0.00000479
AC:
7
AN:
1461892
Hom.:
0
Cov.:
32
AF XY:
0.00000413
AC XY:
3
AN XY:
727248
show subpopulations
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:
0.00000540
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Multiple congenital exostosis Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJun 22, 2022In 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with EXT1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 724 of the EXT1 protein (p.Leu724Phe). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.60
BayesDel_addAF
Pathogenic
0.23
D
BayesDel_noAF
Uncertain
0.090
CADD
Pathogenic
30
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.60
D
Eigen
Uncertain
0.66
Eigen_PC
Pathogenic
0.72
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
1.0
D
M_CAP
Benign
0.042
D
MetaRNN
Pathogenic
0.81
D
MetaSVM
Uncertain
0.32
D
MutationAssessor
Uncertain
2.3
M
MutationTaster
Benign
1.0
D
PrimateAI
Pathogenic
0.83
D
PROVEAN
Benign
-1.8
N
REVEL
Uncertain
0.64
Sift
Benign
0.089
T
Sift4G
Benign
0.15
T
Polyphen
0.87
P
Vest4
0.61
MutPred
0.68
Loss of stability (P = 0.078);
MVP
0.71
MPC
2.5
ClinPred
0.97
D
GERP RS
6.0
Varity_R
0.39
gMVP
0.69

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.18
Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr8-118812022; API