X-37780096-A-C

Position:

• chrX-37780096-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_000397.4(CYBB):​c.19A>C​(p.Asn7His) 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: 22)
• Consequence: CYBB NM_000397.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.43

Genes affected

CYBB (HGNC:2578): (cytochrome b-245 beta chain) Cytochrome b (-245) is composed of cytochrome b alpha (CYBA) and beta (CYBB) chain. It has been proposed as a primary component of the microbicidal oxidase system of phagocytes. CYBB deficiency is one of five described biochemical defects associated with chronic granulomatous disease (CGD). In this disorder, there is decreased activity of phagocyte NADPH oxidase; neutrophils are able to phagocytize bacteria but cannot kill them in the phagocytic vacuoles. The cause of the killing defect is an inability to increase the cell's respiration and consequent failure to deliver activated oxygen into the phagocytic vacuole. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.905

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CYBB	NM_000397.4	c.19A>C	p.Asn7His	missense_variant	1/13	ENST00000378588.5	NP_000388.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CYBB	ENST00000378588.5	c.19A>C	p.Asn7His	missense_variant	1/13	1	NM_000397.4	ENSP00000367851	P1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 22

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Granulomatous disease, chronic, X-linked Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 08, 2024

This sequence change replaces asparagine, which is neutral and polar, with histidine, which is basic and polar, at codon 7 of the CYBB protein (p.Asn7His). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CYBB-related conditions. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on CYBB protein function. 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	Uncertain	0.55
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.21
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.66	D
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.78	T
M_CAP	Pathogenic	0.80	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.8	M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.69	T
PROVEAN	Uncertain	-3.3	D
REVEL	Pathogenic	0.84
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.86
MutPred		0.62		Loss of sheet (P = 0.1158);
MVP		1.0
MPC		1.6
ClinPred		0.99	D
GERP RS		5.4
Varity_R		0.72
gMVP		0.92

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: rs1890282710; hg19: chrX-37639349;