chr1-26022863-C-T

Variant names:

• chr1-26022863-C-T
• rs200312696
• NM_004455.3:c.217C>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_004455.3(EXTL1):​c.217C>T​(p.Gln73*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,728 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: EXTL1 NM_004455.3 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.07
• Publications: 0 publications found

Genes affected

EXTL1 (HGNC:3515): (exostosin like glycosyltransferase 1) This gene is a member of the multiple exostoses (EXT) family of glycosyltransferases, which function in the chain polymerization of heparan sulfate and heparin. The encoded protein harbors alpha 1,4- N-acetylglucosaminyltransferase activity, and is involved in chain elongation of heparan sulfate and possibly heparin. [provided by RefSeq, Jul 2008]

ENSG00000310101 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004455.3. 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
	EXTL1	NM_004455.3	MANE Select	c.217C>T	p.Gln73*	stop_gained	Exon 1 of 11	NP_004446.2	Q92935

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	EXTL1	ENST00000374280.4	TSL:1 MANE Select	c.217C>T	p.Gln73*	stop_gained	Exon 1 of 11	ENSP00000363398.3	Q92935
	EXTL1	ENST00000882621.1		c.217C>T	p.Gln73*	stop_gained	Exon 1 of 11	ENSP00000552680.1
	EXTL1	ENST00000882616.1		c.217C>T	p.Gln73*	stop_gained	Exon 1 of 10	ENSP00000552675.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461728 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727180

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86242

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53338

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111964

Other (OTH) AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.20
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Benign	0.16
Eigen_PC	Benign	-0.14
FATHMM_MKL	Benign	0.23	N
PhyloP100		1.1
Vest4		0.070
GERP RS		2.3
Mutation Taster		=36/164	disease causing (fs/PTC)

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: rs200312696; hg19: chr1-26349354;