8-42306374-C-T

Position:

• chr8-42306374-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP2 PP3_Strong

The NM_001556.3(IKBKB):​c.509C>T​(p.Ala170Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: IKBKB NM_001556.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.90

Genes affected

IKBKB (HGNC:5960): (inhibitor of nuclear factor kappa B kinase subunit beta) The protein encoded by this gene phosphorylates the inhibitor in the inhibitor/NF-kappa-B complex, causing dissociation of the inhibitor and activation of NF-kappa-B. The encoded protein itself is found in a complex of proteins. Several transcript variants, some protein-coding and some not, have been found for this gene. [provided by RefSeq, Sep 2011]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), IKBKB. . Gene score misZ 2.5876 (greater than the threshold 3.09). Trascript score misZ 3.3125 (greater than threshold 3.09). GenCC has associacion of gene with immunodeficiency 15a, severe combined immunodeficiency due to IKK2 deficiency.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.973

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IKBKB	NM_001556.3	c.509C>T	p.Ala170Val	missense_variant	7/22	ENST00000520810.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IKBKB	ENST00000520810.6	c.509C>T	p.Ala170Val	missense_variant	7/22	1	NM_001556.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Severe combined immunodeficiency due to IKK2 deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 29, 2017

This sequence change replaces alanine with valine at codon 170 of the IKBKB protein (p.Ala170Val). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and valine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with IKBKB-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.36	T;.;T;.;T
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.97	.;D;D;D;D
M_CAP	Uncertain	0.16	D
MetaRNN	Pathogenic	0.97	D;D;D;D;D
MetaSVM	Uncertain	0.40	D
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Pathogenic	0.87	D
PROVEAN	Uncertain	-3.8	D;D;.;D;.
REVEL	Pathogenic	0.86
Sift	Uncertain	0.0010	D;D;.;D;.
Sift4G	Uncertain	0.0030	D;D;D;D;.
Polyphen		1.0	D;.;.;D;D
Vest4		0.97
MutPred		0.92		Gain of methylation at K171 (P = 0.035);.;Gain of methylation at K171 (P = 0.035);.;Gain of methylation at K171 (P = 0.035);
MVP		0.94
MPC		2.2
ClinPred		0.99	D
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.83
gMVP		0.89

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: rs1554518965; hg19: chr8-42163892;