rs749633690

Variant names:

• chr9-368016-A-G
• rs749633690
• NM_203447.4:c.1680-2A>G

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_203447.4(DOCK8):​c.1680-2A>G variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000343 in 1,458,008 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: DOCK8 NM_203447.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 9.18
• Publications: 0 publications found

Genes affected

DOCK8 (HGNC:19191): (dedicator of cytokinesis 8) This gene encodes a member of the DOCK180 family of guanine nucleotide exchange factors. Guanine nucleotide exchange factors interact with Rho GTPases and are components of intracellular signaling networks. Mutations in this gene result in the autosomal recessive form of the hyper-IgE syndrome. Alternatively spliced transcript variants encoding different isoforms have been described.[provided by RefSeq, Jun 2010]

DOCK8 Gene-Disease associations (from GenCC):

• combined immunodeficiency due to DOCK8 deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: Orphanet, ClinGen, Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics, Genomics England PanelApp
• autosomal dominant non-syndromic intellectual disability

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• complex neurodevelopmental disorder

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 9.3, offset of 25, new splice context is: ttctctatgtctacccacAGagg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 9-368016-A-G is Pathogenic according to our data. Variant chr9-368016-A-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 572171.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DOCK8	NM_203447.4	c.1680-2A>G		splice_acceptor_variant, intron_variant	Intron 14 of 47	ENST00000432829.7	NP_982272.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DOCK8	ENST00000432829.7	c.1680-2A>G		splice_acceptor_variant, intron_variant	Intron 14 of 47	1	NM_203447.4	ENSP00000394888.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251316 AF XY: 0.00000736

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000343 AC: 5 AN: 1458008 Hom.: 0 Cov.: 29 AF XY: 0.00000276 AC XY: 2 AN XY: 725664

African (AFR) AF: 0.00 AC: 0 AN: 33350

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26110

East Asian (EAS) AF: 0.00 AC: 0 AN: 39686

South Asian (SAS) AF: 0.00 AC: 0 AN: 86180

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5752

European-Non Finnish (NFE) AF: 0.00000451 AC: 5 AN: 1108502

Other (OTH) AF: 0.00 AC: 0 AN: 60296

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.000119

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

May 12, 2020

AiLife Diagnostics, AiLife Diagnostics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Pathogenic:1

Jan 01, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 DOCK8 are known to be pathogenic (PMID: 14722525, 19776401). 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 DOCK8-related conditions. ClinVar contains an entry for this variant (Variation ID: 572171). This variant is present in population databases (rs749633690, ExAC 0.001%). This sequence change affects an acceptor splice site in intron 14 of the DOCK8 gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.61	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	35
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.99
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		9.2
GERP RS		5.3
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.75		Position offset: 27
DS_AL_spliceai		1.0		Position offset: 2

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

Other links and lift over

dbSNP: rs749633690; hg19: chr9-368016;