rs193922449

Variant names:

• chrX-37796074-G-T
• rs193922449
• NM_000397.4:c.607G>T

Variant summary

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

The NM_000397.4(CYBB):​c.607G>T​(p.Glu203*) variant causes a stop gained 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 Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 22)
• Consequence: CYBB NM_000397.4 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 9.60
• Publications: 3 publications found

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]

CYBB Gene-Disease associations (from GenCC):

• granulomatous disease, chronic, X-linked

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• chronic granulomatous disease

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• X-linked Mendelian susceptibility to mycobacterial diseases due to CYBB deficiency

  Inheritance: XL, Unknown Classification: SUPPORTIVE, LIMITED Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)

ENSG00000250349 (HGNC:):

ACMG classification

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

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-37796074-G-T is Pathogenic according to our data. Variant chrX-37796074-G-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 35974.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
CYBB	NM_000397.4	c.607G>T	p.Glu203*	stop_gained	Exon 6 of 13	ENST00000378588.5	NP_000388.2
CYBB	XM_047441855.1	c.301G>T	p.Glu101*	stop_gained	Exon 5 of 12		XP_047297811.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CYBB	ENST00000378588.5	c.607G>T	p.Glu203*	stop_gained	Exon 6 of 13	1	NM_000397.4	ENSP00000367851.4
ENSG00000250349	ENST00000465127.1	c.171+370074G>T		intron_variant	Intron 3 of 8	5		ENSP00000417050.1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 22

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Granulomatous disease, chronic, X-linked Pathogenic:2

Aug 18, 2011

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing;curation

- -

Aug 14, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in CYBB are known to be pathogenic (PMID: 9585602, 20729109). This variant has been observed in individuals affected with chronic granulomatous disease (PMID: 8634410, 20729109). ClinVar contains an entry for this variant (Variation ID: 35974). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Glu203*) in the CYBB gene. It is expected to result in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	38
DANN	Uncertain	1.0
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		9.6
Vest4		0.92
GERP RS		5.3
Mutation Taster		=1/199	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs193922449; hg19: chrX-37655327;