22-20859018-G-T

Position:

• chr22-20859018-G-T

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The NM_004782.4(SNAP29):​c.-93G>T variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000245 in 1,374,030 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00020 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00025 (3 hom.)
• Consequence: SNAP29 NM_004782.4 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.25

Genes affected

SNAP29 (HGNC:11133): (synaptosome associated protein 29) This gene, a member of the SNAP25 gene family, encodes a protein involved in multiple membrane trafficking steps. Two other members of this gene family, SNAP23 and SNAP25, encode proteins that bind a syntaxin protein and mediate synaptic vesicle membrane docking and fusion to the plasma membrane. The protein encoded by this gene binds tightly to multiple syntaxins and is localized to intracellular membrane structures rather than to the plasma membrane. While the protein is mostly membrane-bound, a significant fraction of it is found free in the cytoplasm. Use of multiple polyadenylation sites has been noted for this gene. [provided by RefSeq, Jul 2008]

PI4KA (HGNC:8983): (phosphatidylinositol 4-kinase alpha) This gene encodes a phosphatidylinositol (PI) 4-kinase which catalyzes the first committed step in the biosynthesis of phosphatidylinositol 4,5-bisphosphate. The mammalian PI 4-kinases have been classified into two types, II and III, based on their molecular mass, and modulation by detergent and adenosine. The protein encoded by this gene is a type III enzyme that is not inhibited by adenosine. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Apr 2018]

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.69).
• BS1: Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.000204 (31/152182) while in subpopulation SAS AF= 0.00228 (11/4826). AF 95% confidence interval is 0.00128. There are 0 homozygotes in gnomad4. There are 19 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High Homozygotes in GnomAdExome4 at 3 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SNAP29	NM_004782.4	c.-93G>T		5_prime_UTR_variant	1/5	ENST00000215730.12	NP_004773.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SNAP29	ENST00000215730.12	c.-93G>T		5_prime_UTR_variant	1/5	1	NM_004782.4	ENSP00000215730	P1
PI4KA	ENST00000449120.1	c.-19+105C>A		intron_variant		4		ENSP00000402437

Frequencies

GnomAD3 genomes AF: 0.000204 AC: 31 AN: 152072 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00433

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00228

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00143

GnomAD4 exome AF: 0.000250 AC: 306 AN: 1221848 Hom.: 3 Cov.: 18 AF XY: 0.000328 AC XY: 200 AN XY: 609270

Gnomad4 AFR exome AF: 0.0000379

Gnomad4 AMR exome AF: 0.0000391

Gnomad4 ASJ exome AF: 0.00329

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00225

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000574

Gnomad4 OTH exome AF: 0.000408

GnomAD4 genome AF: 0.000204 AC: 31 AN: 152182 Hom.: 0 Cov.: 33 AF XY: 0.000255 AC XY: 19 AN XY: 74436

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00433

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00228

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00142

Bravo AF: 0.0000982

Asia WGS AF: 0.000578 AC: 2 AN: 3476

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

CEDNIK syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.69
CADD	Benign	2.9
DANN	Benign	0.64
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

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: rs534931954; hg19: chr22-21213306;