rs1553140060

Variant names:

• chr1-43920490-C-T
• rs1553140060
• NM_006279.5:c.831C>T
• ST3GAL3 p.Ile277Ile

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Moderate BP6_Moderate

The NM_001270459.2(ST3GAL3):​c.745-4C>T variant causes a splice region, intron change. The variant allele was found at a frequency of 0.000000684 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ST3GAL3 NM_001270459.2 splice_region, intron
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 4.50
• 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, PanelApp Australia
• 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: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (REVEL=0.168).
• BP6: Variant 1-43920490-C-T is Benign according to our data. Variant chr1-43920490-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 461330.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001270459.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ST3GAL3	NM_006279.5	MANE Select	c.831C>T	p.Ile277Ile	synonymous	Exon 10 of 12	NP_006270.1	Q11203-1
	ST3GAL3	NM_001350619.2		c.876C>T	p.Ile292Ile	synonymous	Exon 10 of 13	NP_001337548.1	A0A2R8YDJ6
	ST3GAL3	NM_174963.5		c.1038C>T	p.Ile346Ile	synonymous	Exon 11 of 13	NP_777623.2	Q11203-4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ST3GAL3	ENST00000347631.8	TSL:5 MANE Select	c.831C>T	p.Ile277Ile	synonymous	Exon 10 of 12	ENSP00000317192.6	Q11203-1
	ST3GAL3	ENST00000372372.7	TSL:1	c.945C>T	p.Ile315Ile	synonymous	Exon 10 of 12	ENSP00000361447.2	Q11203-19
	ST3GAL3	ENST00000361746.9	TSL:1	c.924C>T	p.Ile308Ile	synonymous	Exon 11 of 13	ENSP00000354657.5	A0A2U3TZK9

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461892 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

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

American (AMR) AF: 0.00 AC: 0 AN: 44724

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112012

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

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Likely benign

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	-	1	Developmental and epileptic encephalopathy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_noAF	Benign	-0.27
CADD	Benign	13
DANN	Uncertain	0.99
PhyloP100		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=52/48	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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs1553140060;

hg19: chr1-44386162;