4-89834926-T-G

Position:

• chr4-89834926-T-G

Variant summary

Our verdict is Benign. Variant got -12 ACMG points: 0P and 12B. BP4_Strong BA1

The NM_000345.4(SNCA):​c.121+621A>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0945 in 152,260 control chromosomes in the GnomAD database, including 839 homozygotes. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.094 (839 hom., cov: 33)
• Consequence: SNCA NM_000345.4 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.610

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]

ACMG classification

Verdict is Benign. Variant got -12 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.85).
• BA1: GnomAd4 highest subpopulation (EAS) allele frequency at 95% confidence interval = 0.195 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SNCA	NM_000345.4	c.121+621A>C		intron_variant		ENST00000394991.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SNCA	ENST00000394991.8	c.121+621A>C		intron_variant		1	NM_000345.4	P1

Frequencies

GnomAD3 genomes AF: 0.0945 AC: 14384 AN: 152142 Hom.: 839 Cov.: 33

Gnomad AFR AF: 0.115

Gnomad AMI AF: 0.0230

Gnomad AMR AF: 0.137

Gnomad ASJ AF: 0.113

Gnomad EAS AF: 0.206

Gnomad SAS AF: 0.181

Gnomad FIN AF: 0.0714

Gnomad MID AF: 0.139

Gnomad NFE AF: 0.0610

Gnomad OTH AF: 0.108

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome AF: 0.0945 AC: 14388 AN: 152260 Hom.: 839 Cov.: 33 AF XY: 0.0969 AC XY: 7216 AN XY: 74448

Gnomad4 AFR AF: 0.115

Gnomad4 AMR AF: 0.137

Gnomad4 ASJ AF: 0.113

Gnomad4 EAS AF: 0.206

Gnomad4 SAS AF: 0.179

Gnomad4 FIN AF: 0.0714

Gnomad4 NFE AF: 0.0609

Gnomad4 OTH AF: 0.108

Alfa AF: 0.0890 Hom.: 129

Bravo AF: 0.0988

Asia WGS AF: 0.184 AC: 639 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.85
CADD	Benign	5.4
DANN	Benign	0.51

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: rs2035268; hg19: chr4-90756077;