1-43736288-A-G

Variant names:

• chr1-43736288-A-G
• rs1441726807
• NM_006279.5:c.26A>G

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_006279.5(ST3GAL3):​c.26A>G​(p.Asn9Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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. N9H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: ST3GAL3 NM_006279.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.26
• Publications: 0 publications found

Genes affected

ST3GAL3 (HGNC:10866): (ST3 beta-galactoside alpha-2,3-sialyltransferase 3) The protein encoded by this gene is a type II membrane protein that catalyzes the transfer of sialic acid from CMP-sialic acid to galactose-containing substrates. The encoded protein is normally found in the Golgi apparatus but can be proteolytically processed to a soluble form. This protein is a member of glycosyltransferase family 29. Mutations in this gene have been associated with a form of autosomal recessive nonsymdromic cognitive disability as well as infantile epileptic encephalopathy. Multiple transcript variants encoding several different isoforms have been found for this gene. [provided by RefSeq, Jul 2017]

ST3GAL3 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 15

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• intellectual disability, autosomal recessive 12

  Inheritance: AR Classification: STRONG Submitted by: G2P
• complex neurodevelopmental disorder

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen
• infantile spasms

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive non-syndromic intellectual disability

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000284989 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.38038594).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ST3GAL3	NM_006279.5	c.26A>G	p.Asn9Ser	missense_variant	Exon 2 of 12	ENST00000347631.8	NP_006270.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ST3GAL3	ENST00000347631.8	c.26A>G	p.Asn9Ser	missense_variant	Exon 2 of 12	5	NM_006279.5	ENSP00000317192.6
ENSG00000284989	ENST00000645057.1	n.*1348A>G		non_coding_transcript_exon_variant	Exon 16 of 26			ENSP00000494063.1
ENSG00000284989	ENST00000645057.1	n.*1348A>G		3_prime_UTR_variant	Exon 16 of 26			ENSP00000494063.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000795 AC: 2 AN: 251484 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461882 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 727244

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1112004

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy Uncertain:1

Aug 31, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine with serine at codon 9 of the ST3GAL3 protein (p.Asn9Ser). The asparagine residue is moderately conserved and there is a small physicochemical difference between asparagine and serine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with ST3GAL3-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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	0.15
BayesDel_addAF	Benign	-0.074	T
BayesDel_noAF	Benign	-0.26
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Benign	0.097	T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.;.;.;.;T;.;.;.;.;.;.;.;.;.;.;.;.
Eigen	Uncertain	0.60
Eigen_PC	Uncertain	0.64
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.96	.;D;D;D;D;D;D;D;D;D;D;D;D;D;D;.;D;D;D;D;D;D;D;D;D;D;D;D;D;D;.;D;.;.
M_CAP	Benign	0.038	D
MetaRNN	Benign	0.38	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.10	T
MutationAssessor	Benign	1.4	L;L;L;L;L;L;L;.;.;.;L;.;L;L;L;L;.;L;.;.;.;L;.;.;L;L;L;L;L;L;L;L;L;L
PhyloP100		6.3
PrimateAI	Pathogenic	0.83	D
PROVEAN	Benign	-1.1	N;N;N;D;D;N;N;.;.;.;N;.;N;.;N;.;.;N;.;N;.;.;N;.;D;D;N;N;N;N;D;N;D;N
REVEL	Benign	0.21
Sift	Benign	0.081	T;T;T;T;T;T;T;.;.;.;T;.;T;.;T;.;.;D;.;D;.;.;D;.;T;T;T;T;T;T;T;T;T;T
Sift4G	Benign	0.22	T;T;T;T;D;T;T;.;.;.;T;.;T;.;T;.;.;T;.;T;.;.;T;.;T;T;T;T;T;T;D;T;T;T
Polyphen		0.96	P;D;D;.;D;D;D;.;.;.;.;.;D;D;D;P;.;D;.;.;.;P;.;.;D;D;D;D;.;D;D;D;.;D
Vest4		0.63
MutPred		0.41		Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);
MVP		0.85
MPC		0.45
ClinPred		0.65	D
GERP RS		5.9
PromoterAI		-0.0096	Neutral
Varity_R		0.10
gMVP		0.63
Mutation Taster		=80/20	polymorphism

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

Other links and lift over

dbSNP: rs1441726807; hg19: chr1-44201959;