1-100877641-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001033025.3(EXTL2):c.268C>T(p.Pro90Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,416 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: 6.8e-7 (0 hom.)
• Consequence: EXTL2 NM_001033025.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.52

Genes affected

EXTL2 (HGNC:3516): (exostosin like glycosyltransferase 2) Enables alpha-1,4-N-acetylgalactosaminyltransferase activity and glucuronyl-galactosyl-proteoglycan 4-alpha-N-acetylglucosaminyltransferase activity. Involved in N-acetylglucosamine metabolic process and UDP-N-acetylgalactosamine metabolic process. Located in cytosol; endoplasmic reticulum; and nucleoplasm. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.932

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
EXTL2	NM_001033025.3	c.268C>T	p.Pro90Ser	missense_variant	3/5	ENST00000370114.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
EXTL2	ENST00000370114.8	c.268C>T	p.Pro90Ser	missense_variant	3/5	1	NM_001033025.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251126 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135714

Gnomad AFR exome AF: 0.0000616

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461416 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727008

Gnomad4 AFR exome AF: 0.0000299

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 15, 2023

The c.268C>T (p.P90S) alteration is located in exon 3 (coding exon 2) of the EXTL2 gene. This alteration results from a C to T substitution at nucleotide position 268, causing the proline (P) at amino acid position 90 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Uncertain	0.063	T
BayesDel_noAF	Uncertain	0.030
Cadd	Pathogenic	27
Dann	Uncertain	1.0
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.66
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;.;D;D;D
M_CAP	Benign	0.052	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D
MetaSVM	Uncertain	-0.027	T
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.60	T
REVEL	Uncertain	0.57
Sift4G	Pathogenic	0.0	D;T;T;.;D
Polyphen		0.96	.;P;P;.;.
Vest4		0.79
MutPred		0.77		Gain of MoRF binding (P = 0.1003);Gain of MoRF binding (P = 0.1003);Gain of MoRF binding (P = 0.1003);.;.;
MVP		0.92
MPC		0.63
ClinPred		0.91	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.49
gMVP		0.61

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: rs753971587; hg19: chr1-101343197;