16-3025921-CA-C

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1 PM2 PP3_Moderate PP5_Moderate

The NM_024339.5(THOC6):c.156-2del variant causes a splice acceptor change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: THOC6 NM_024339.5 splice_acceptor
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1 O:1
• Conservation: PhyloP100: 7.84

Genes affected

THOC6 (HGNC:28369): (THO complex subunit 6) This gene encodes a subunit of the multi-protein THO complex, which is involved in coordination between transcription and mRNA processing. The THO complex is a component of the TREX (transcription/export) complex, which is involved in transcription and export of mRNAs. A missense mutation in this gene is associated with a neurodevelopmental disorder called Beaulieu-Boycott-Innes syndrome. [provided by RefSeq, Dec 2016]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 16-3025921-CA-C is Pathogenic according to our data. Variant chr16-3025921-CA-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1068138.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
THOC6	NM_024339.5	c.156-2del		splice_acceptor_variant		ENST00000326266.13
THOC6	NM_001142350.3	c.156-2del		splice_acceptor_variant
THOC6	NM_001347703.2	c.84-2del		splice_acceptor_variant
THOC6	NM_001347704.2	c.156-2del		splice_acceptor_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
THOC6	ENST00000326266.13	c.156-2del		splice_acceptor_variant		1	NM_024339.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 36

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Invitae

Oct 11, 2017

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Donor and acceptor splice site variants typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in THOC6 are known to be pathogenic (PMID: 26739162, 27102954). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. This variant has not been reported in the literature in individuals with THOC6-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change affects an acceptor splice site in intron 2 of the THOC6 gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. -

THOC6-related developmental delay-microcephaly-facial dysmorphism syndrome Other:1

not provided, no classification provided

phenotyping only

GenomeConnect - Invitae Patient Insights Network

-

Variant classified as Likely pathogenic and reported on 01-08-2018 by Invitae. GenomeConnect-Invitae Patient Insights Network assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. Registry team members make no attempt to reinterpret the clinical significance of the variant. Phenotypic details are available under supporting information. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.77		Position offset: 26
DS_AL_spliceai		1.0		Position offset: 3

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr16-3075922;