8-117822522-C-G

Variant names:

• chr8-117822522-C-G
• rs201504622
• NM_000127.3:c.1360G>C

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 4P and 5B. PM2 PM5 BP4 BS2

The NM_000127.3(EXT1):​c.1360G>C​(p.Val454Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,460,996 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V454I) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: EXT1 NM_000127.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.03

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]

ACMG classification

Verdict is Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr8-117822522-C-T is described in Lovd as [Likely_pathogenic].
• BP4: Computational evidence support a benign effect (MetaRNN=0.33404368).
• BS2: High AC in GnomAdExome4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
EXT1	NM_000127.3	c.1360G>C	p.Val454Leu	missense_variant	Exon 5 of 11	ENST00000378204.7	NP_000118.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
EXT1	ENST00000378204.7	c.1360G>C	p.Val454Leu	missense_variant	Exon 5 of 11	1	NM_000127.3	ENSP00000367446.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000120 AC: 3 AN: 250834 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135584

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 SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1460996 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 726838

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: 0.0000348

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Uncertain	0.048	T
BayesDel_noAF	Uncertain	0.010
CADD	Benign	21
DANN	Uncertain	0.99
DEOGEN2	Benign	0.38	T
Eigen	Benign	-0.21
Eigen_PC	Benign	0.064
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.91	D
M_CAP	Benign	0.051	D
MetaRNN	Benign	0.33	T
MetaSVM	Uncertain	0.091	D
MutationAssessor	Benign	1.1	L
PrimateAI	Uncertain	0.68	T
PROVEAN	Benign	-0.78	N
REVEL	Uncertain	0.38
Sift	Benign	0.30	T
Sift4G	Benign	0.43	T
Polyphen		0.0030	B
Vest4		0.48
MutPred		0.32		Gain of sheet (P = 0.1945);
MVP		0.76
MPC		0.44
ClinPred		0.16	T
GERP RS		6.1
Varity_R		0.13
gMVP		0.73

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: rs201504622; hg19: chr8-118834761;