rs147305893

Positions:

• chr2-85840275-C-G
• chr2-85840275-C-T

Variant summary

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

The NM_003896.4(ST3GAL5):​c.1126G>C​(p.Asp376His) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,886 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D376N) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ST3GAL5 NM_003896.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.03

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 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.89

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ST3GAL5	NM_003896.4	c.1126G>C	p.Asp376His	missense_variant	7/7	ENST00000638572.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ST3GAL5	ENST00000638572.2	c.1126G>C	p.Asp376His	missense_variant	7/7	1	NM_003896.4	A1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251396 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135858

Gnomad AFR exome AF: 0.0000615

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: 1461886 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

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

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

Jul 12, 2018

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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. 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 disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with ST3GAL5-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces aspartic acid with histidine at codon 376 of the ST3GAL5 protein (p.Asp376His). The aspartic acid residue is highly conserved and there is a moderate physicochemical difference between aspartic acid and histidine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.58
BayesDel_addAF	Benign	-0.057	T
BayesDel_noAF	Benign	-0.14
CADD	Uncertain	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.63	D;.;.;.;.;.;.;.;.;.;T;.
Eigen	Pathogenic	0.73
Eigen_PC	Uncertain	0.66
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.93	D;D;.;.;D;D;D;.;.;.;D;D
M_CAP	Benign	0.051	D
MetaRNN	Pathogenic	0.89	D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Benign	-0.53	T
MutationAssessor	Pathogenic	3.0	M;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.45	T
PROVEAN	Uncertain	-3.4	.;D;D;.;.;.;.;.;.;.;.;.
REVEL	Uncertain	0.33
Sift	Uncertain	0.0040	.;D;D;.;.;.;.;.;.;.;.;.
Sift4G	Uncertain	0.0090	.;D;D;.;.;.;.;.;.;.;.;.
Polyphen		1.0	D;D;D;D;.;.;.;D;D;D;.;D
Vest4		0.55, 0.55
MutPred		0.77		Gain of catalytic residue at D376 (P = 0.1227);.;.;.;.;.;.;.;.;.;.;.;
MVP		0.66
MPC		1.1
ClinPred		0.97	D
GERP RS		4.9
Varity_R		0.75
gMVP		0.67

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs147305893; hg19: chr2-86067398;