4-89828170-C-T

Variant names:

• chr4-89828170-C-T
• rs104893875
• NM_000345.4:c.136G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Moderate PP5_Moderate

The NM_000345.4(SNCA):​c.136G>A​(p.Glu46Lys) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SNCA NM_000345.4 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 4.37
• Publications: 1403 publications found

Genes affected

SNCA (HGNC:11138): (synuclein alpha) Alpha-synuclein is a member of the synuclein family, which also includes beta- and gamma-synuclein. Synucleins are abundantly expressed in the brain and alpha- and beta-synuclein inhibit phospholipase D2 selectively. SNCA may serve to integrate presynaptic signaling and membrane trafficking. Defects in SNCA have been implicated in the pathogenesis of Parkinson disease. SNCA peptides are a major component of amyloid plaques in the brains of patients with Alzheimer's disease. Alternatively spliced transcripts encoding different isoforms have been identified for this gene. [provided by RefSeq, Feb 2016]

SNCA Gene-Disease associations (from GenCC):

• autosomal dominant Parkinson disease 4

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• Parkinson disease

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen, Ambry Genetics
• autosomal dominant Parkinson disease 1

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• Lewy body dementia

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• hereditary late onset Parkinson disease

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• parkinsonian-pyramidal syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 1 uncertain in NM_000345.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.851
• PP5: Variant 4-89828170-C-T is Pathogenic according to our data. Variant chr4-89828170-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 14010.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SNCA	NM_000345.4	c.136G>A	p.Glu46Lys	missense_variant	Exon 3 of 6	ENST00000394991.8	NP_000336.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SNCA	ENST00000394991.8	c.136G>A	p.Glu46Lys	missense_variant	Exon 3 of 6	1	NM_000345.4	ENSP00000378442.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Lewy body dementia;C1868595:Autosomal dominant Parkinson disease 1 Pathogenic:1

Aug 04, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 14010). This missense change has been observed in individual(s) with Parkinson disease and dementia with Lewy bodies (PMID: 14755719, 16001411). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 46 of the SNCA protein (p.Glu46Lys). -

Lewy body dementia Pathogenic:1

Mar 04, 2005

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.56
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.070
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	.;D;.;D;D;D;D;.;D
Eigen	Benign	0.13
Eigen_PC	Benign	0.20
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	1.0	D;.;.;.;.;.;D;D;D
M_CAP	Uncertain	0.21	D
MetaRNN	Pathogenic	0.85	D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.41	D
MutationAssessor	Benign	1.6	L;L;L;L;L;L;L;.;.
PhyloP100		4.4
PrimateAI	Uncertain	0.72	T
PROVEAN	Uncertain	-3.4	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.73
Sift	Uncertain	0.0050	D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.059	T;T;T;T;T;T;T;T;.
Polyphen		0.0010	B;P;B;P;P;P;P;.;.
Vest4		0.69
MutPred		0.80		Gain of MoRF binding (P = 0.0064);Gain of MoRF binding (P = 0.0064);Gain of MoRF binding (P = 0.0064);Gain of MoRF binding (P = 0.0064);Gain of MoRF binding (P = 0.0064);Gain of MoRF binding (P = 0.0064);Gain of MoRF binding (P = 0.0064);Gain of MoRF binding (P = 0.0064);Gain of MoRF binding (P = 0.0064);
MVP		0.94
MPC		0.56
ClinPred		0.98	D
GERP RS		3.5
Varity_R		0.85
gMVP		0.65
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
Splicevardb		2.0
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

Other links and lift over

dbSNP: rs104893875; hg19: chr4-90749321;