2-85846395-C-T

Position:

• chr2-85846395-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_003896.4(ST3GAL5):​c.831G>A​(p.Met277Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000479 in 1,461,738 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign 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: ST3GAL5 NM_003896.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.63

Genes affected

ST3GAL5 (HGNC:10872): (ST3 beta-galactoside alpha-2,3-sialyltransferase 5) Ganglioside GM3 is known to participate in the induction of cell differentiation, modulation of cell proliferation, maintenance of fibroblast morphology, signal transduction, and integrin-mediated cell adhesion. The protein encoded by this gene is a type II membrane protein which catalyzes the formation of GM3 using lactosylceramide as the substrate. The encoded protein is a member of glycosyltransferase family 29 and may be localized to the Golgi apparatus. Mutation in this gene has been associated with Amish infantile epilepsy syndrome. Transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.20425737).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ST3GAL5	NM_003896.4	c.831G>A	p.Met277Ile	missense_variant	5/7	ENST00000638572.2	NP_003887.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ST3GAL5	ENST00000638572.2	c.831G>A	p.Met277Ile	missense_variant	5/7	1	NM_003896.4	ENSP00000491316	A1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461738 Hom.: 0 Cov.: 30 AF XY: 0.00000550 AC XY: 4 AN XY: 727172

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: 0.00000630

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

TwinsUK AF: 0.00 AC: 0

ALSPAC AF: 0.000259 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

GM3 synthase deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 28, 2022

This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 277 of the ST3GAL5 protein (p.Met277Ile). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ST3GAL5-related conditions. ClinVar contains an entry for this variant (Variation ID: 566048). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.49
CADD	Benign	23
DANN	Benign	0.79
DEOGEN2	Benign	0.19	T;.;.;.;.;.;.;.;.;.;T;.
Eigen	Benign	-0.26
Eigen_PC	Benign	-0.076
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.87	D;D;.;.;D;D;D;.;.;.;D;D
M_CAP	Benign	0.012	T
MetaRNN	Benign	0.20	T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.1	L;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-0.27	.;N;N;.;.;.;.;.;.;.;.;.
REVEL	Benign	0.071
Sift	Benign	0.65	.;T;T;.;.;.;.;.;.;.;.;.
Sift4G	Benign	0.82	.;T;T;.;.;.;.;.;.;.;.;.
Polyphen		0.16	B;B;B;B;.;.;.;B;B;B;.;B
Vest4		0.32, 0.32
MutPred		0.68		Loss of catalytic residue at M277 (P = 0.0167);.;.;.;.;Loss of catalytic residue at M277 (P = 0.0167);.;.;.;.;.;.;
MVP		0.061
MPC		0.35
ClinPred		0.78	D
GERP RS		4.8
Varity_R		0.31
gMVP		0.89

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: rs751569436; hg19: chr2-86073518;