4-89724401-G-T

Position:

• chr4-89724401-G-T

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 0P and 10B. BP4_Strong BP6_Moderate BS2

The NM_000345.4(SNCA):​c.*2227C>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000985 in 152,232 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.000099 (1 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SNCA NM_000345.4 3_prime_UTR
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.141

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]

LOC124900602 (HGNC:):

ACMG classification

Verdict is Benign. Variant got -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.91).
• BP6: Variant 4-89724401-G-T is Benign according to our data. Variant chr4-89724401-G-T is described in ClinVar as [Likely_benign]. Clinvar id is 350062.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS2: High AC in GnomAd4 at 15 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SNCA	NM_000345.4	c.*2227C>A		3_prime_UTR_variant	6/6	ENST00000394991.8
LOC124900602	XR_007058466.1	n.14278G>T		non_coding_transcript_exon_variant	3/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SNCA	ENST00000394991.8	c.*2227C>A		3_prime_UTR_variant	6/6	1	NM_000345.4	P1
	ENST00000659878.1	n.480-1983G>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes AF: 0.0000986 AC: 15 AN: 152114 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00250

Gnomad SAS AF: 0.000414

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 6 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 4

Gnomad4 NFE exome AF: 0.00

GnomAD4 genome AF: 0.0000985 AC: 15 AN: 152232 Hom.: 1 Cov.: 32 AF XY: 0.000121 AC XY: 9 AN XY: 74418

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00250

Gnomad4 SAS AF: 0.000415

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.000185

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Parkinson Disease, Dominant Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.91
CADD	Benign	0.44
DANN	Benign	0.42

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: rs551886776; hg19: chr4-90645552;