rs387907363

Positions:

• chr22-20881100-C-CA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_004782.4(SNAP29):​c.487dup​(p.Ser163LysfsTer6) variant causes a frameshift change. The variant allele was found at a frequency of 0.0000161 in 1,612,806 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000016 (0 hom.)
• Consequence: SNAP29 NM_004782.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 6.47

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 22-20881100-C-CA is Pathogenic according to our data. Variant chr22-20881100-C-CA is described in ClinVar as [Pathogenic]. Clinvar id is 50295.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SNAP29	NM_004782.4	c.487dup	p.Ser163LysfsTer6	frameshift_variant	3/5	ENST00000215730.12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SNAP29	ENST00000215730.12	c.487dup	p.Ser163LysfsTer6	frameshift_variant	3/5	1	NM_004782.4	P1
SNAP29	ENST00000439214.1	c.208dup	p.Ser70LysfsTer6	frameshift_variant	3/5	3

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152160 Hom.: 0 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: 0.00

Gnomad SAS AF: 0.000415

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000318 AC: 8 AN: 251394 Hom.: 0 AF XY: 0.0000442 AC XY: 6 AN XY: 135870

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000229

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000164 AC: 24 AN: 1460646 Hom.: 0 Cov.: 29 AF XY: 0.0000234 AC XY: 17 AN XY: 726736

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000255

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152160 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74312

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000415

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000113

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 04, 2024	This sequence change creates a premature translational stop signal (p.Ser163Lysfs*6) in the SNAP29 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in SNAP29 are known to be pathogenic (PMID: 15968592, 21073448). This variant is present in population databases (rs768735498, gnomAD 0.03%). This premature translational stop signal has been observed in individual(s) with cerebral dysgenesis, neuropathy, ichthyosis, and palmoplantar keratoderma syndrome (PMID: 21073448). This variant is also known as c.486insA. ClinVar contains an entry for this variant (Variation ID: 50295). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 15, 2023	Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 28388629, 21073448, 25958742, 33977139, 35568357, 31069529) -
Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Oct 25, 2017	- -

CEDNIK syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	research	Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences	-	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Mar 01, 2011	- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs387907363; hg19: chr22-21235388;