Genetic Variant TRAPPC6B:c.268-2_268-1delAG (chr14-39154294-CCT-C) – ACMG Classification: Likely_pathogenic (8 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_StrongPM2PP5_Moderate

The NM_001079537.2(TRAPPC6B):c.268-2_268-1delAG variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.0000174 in 1,605,614 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

TRAPPC6B
NM_001079537.2 splice_acceptor, intron

Scores

Not classified

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 6.84

Variant links:

Genes affected

TRAPPC6B (HGNC:23066): (trafficking protein particle complex subunit 6B) TRAPPC6B is a component of TRAPP complexes, which are tethering complexes involved in vesicle transport (Kummel et al., 2005 [PubMed 16025134]).[supplied by OMIM, Mar 2008]

TRAPPC6B links:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.17610063 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.6, offset of 18, new splice context is: acggcatctatgtacttcAGgac. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 14-39154294-CCT-C is Pathogenic according to our data. Variant chr14-39154294-CCT-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3255618.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TRAPPC6B	NM_001079537.2 link	c.268-2_268-1delAG		splice_acceptor_variant, intron_variant	Intron 3 of 5	ENST00000330149.10	NP_001073005.1	Q86SZ2-1
TRAPPC6B	NM_177452.4 link	c.268-2457_268-2456delAG		intron_variant	Intron 3 of 4		NP_803235.1	Q86SZ2-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TRAPPC6B	ENST00000330149.10 link	c.268-2_268-1delAG		splice_acceptor_variant, intron_variant	Intron 3 of 5	1	NM_001079537.2	ENSP00000330289.5		Q86SZ2-1

Frequencies

GnomAD3 genomes

AF:

0.0000198

AC:

AN:

151542

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000244

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000122

AC:

AN:

245928

Hom.:

AF XY:

0.0000150

AC XY:

AN XY:

133598

show subpopulations

Gnomad AFR exome

AF:

0.0000674

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000179

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000172

AC:

AN:

1454072

Hom.:

AF XY:

0.0000152

AC XY:

AN XY:

723690

show subpopulations

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000217

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000198

AC:

AN:

151542

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

73982

show subpopulations

Gnomad4 AFR

AF:

0.0000244

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000434

Hom.:

Bravo

AF:

0.0000151

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Neurodevelopmental disorder with microcephaly, epilepsy, and brain atrophy

Pathogenic:1

Kasturba Medical College, Manipal, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In-silico analysis tools suchas SpliceAI predict the variant to cause aberrant splicing. The variant c.268-2_268-1del was previouslyreported in four patients from the same family (Almousa et al. 2024). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.99

Details are displayed if max score is > 0.2

DS_AL_spliceai

0.99

Position offset: 0

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over