rs1556471150

Positions:

• chrX-37805019-G-A

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000397.4(CYBB):​c.1165G>A​(p.Gly389Arg) 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. 12/20 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G389E) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 23)
• Consequence: CYBB NM_000397.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 9.60

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]

ENSG00000250349 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a topological_domain Cytoplasmic (size 287) in uniprot entity CY24B_HUMAN there are 20 pathogenic changes around while only 0 benign (100%) in NM_000397.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.995

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CYBB	NM_000397.4	c.1165G>A	p.Gly389Arg	missense_variant	10/13	ENST00000378588.5	NP_000388.2
CYBB	XM_047441855.1	c.859G>A	p.Gly287Arg	missense_variant	9/12		XP_047297811.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CYBB	ENST00000378588.5	c.1165G>A	p.Gly389Arg	missense_variant	10/13	1	NM_000397.4	ENSP00000367851.4
ENSG00000250349	ENST00000465127.1	c.171+379019G>A		intron_variant		5		ENSP00000417050.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Granulomatous disease, chronic, X-linked Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Clinic of Clinical Immunology with Stem Cell Bank, Expert Centre for Rare Diseases - PID, University Hospital "Alexandrovska"

May 01, 2022

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

May 12, 2016

Variant summary: The CYBB c.1165G>A (p.Gly389Arg) variant involves the alteration of a conserved nucleotide, resulting in a missense change from a non-polar Gly to a positively charged Arg residue. Gly389 is a highly conserved amino acid across species located in the dehydrogenase domain of the protein. This variant is located in a mutation hotspot since missense changes at this residue have been cited in multiple X-CGD patients, indicating that missense changes at this residue are not tolerated. 5/5 in silico tools predict a damaging outcome for this variant. Functional studies of other missense changes at Gly389 have been shown to abolish NADPH oxidase activity (Beaumel_Biochem Journal_2014). This variant was absent in 86756 control chromosomes, but has been cited in one patient in CYBB base. Because of the limited clinical information and the lack of functional studies on this particular missense variant, the variant was classified as a variant of uncertain significance (VUS)-possibly pathogenic until additional information becomes available. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.73	D
BayesDel_noAF	Pathogenic	0.82
CADD	Pathogenic	31
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.97	D
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.93	D
MetaRNN	Pathogenic	1.0	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.6	H
PrimateAI	Pathogenic	0.91	D
PROVEAN	Pathogenic	-7.9	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.98
MutPred		0.97		Loss of catalytic residue at G389 (P = 0.0423);
MVP		1.0
MPC		1.7
ClinPred		1.0	D
GERP RS		5.9
Varity_R		1.0
gMVP		0.99

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs1556471150; hg19: chrX-37664272;