1-76627490-C-T

Position:

• chr1-76627490-C-T

Variant summary

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

The NM_152996.4(ST6GALNAC3):​c.662C>T​(p.Thr221Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000548 in 1,460,730 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: 33)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: ST6GALNAC3 NM_152996.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.57

Genes affected

ST6GALNAC3 (HGNC:19343): (ST6 N-acetylgalactosaminide alpha-2,6-sialyltransferase 3) ST6GALNAC3 belongs to a family of sialyltransferases that transfer sialic acids from CMP-sialic acid to terminal positions of carbohydrate groups in glycoproteins and glycolipids (Lee et al., 1999 [PubMed 10207017]).[supplied by OMIM, Mar 2008]

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, 0.888

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ST6GALNAC3	NM_152996.4	c.662C>T	p.Thr221Ile	missense_variant	4/5	ENST00000328299.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ST6GALNAC3	ENST00000328299.4	c.662C>T	p.Thr221Ile	missense_variant	4/5	1	NM_152996.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000548 AC: 8 AN: 1460730 Hom.: 0 Cov.: 29 AF XY: 0.00000413 AC XY: 3 AN XY: 726712

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: 0.00000720

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

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

Jan 29, 2024

The c.662C>T (p.T221I) alteration is located in exon 4 (coding exon 4) of the ST6GALNAC3 gene. This alteration results from a C to T substitution at nucleotide position 662, causing the threonine (T) at amino acid position 221 to be replaced by an isoleucine (I). 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	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.14
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Benign	0.15	T
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.97	D
M_CAP	Benign	0.057	D
MetaRNN	Pathogenic	0.89	D
MetaSVM	Benign	-0.67	T
MutationAssessor	Uncertain	2.8	M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-5.1	D
REVEL	Uncertain	0.62
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.90
MutPred		0.70		Gain of helix (P = 0.2059);
MVP		0.28
MPC		0.39
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.71
gMVP		0.94

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-77093175;