chr6-31946219-G-A

Variant names:

• chr6-31946219-G-A
• rs755016493
• NM_001710.6:c.-3G>A

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_001710.6(CFB):​c.-3G>A variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000123 in 1,460,786 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: CFB NM_001710.6 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: -1.76
• Publications: 0 publications found

Genes affected

CFB (HGNC:1037): (complement factor B) This gene encodes complement factor B, a component of the alternative pathway of complement activation. Factor B circulates in the blood as a single chain polypeptide. Upon activation of the alternative pathway, it is cleaved by complement factor D yielding the noncatalytic chain Ba and the catalytic subunit Bb. The active subunit Bb is a serine protease which associates with C3b to form the alternative pathway C3 convertase. Bb is involved in the proliferation of preactivated B lymphocytes, while Ba inhibits their proliferation. This gene localizes to the major histocompatibility complex (MHC) class III region on chromosome 6. This cluster includes several genes involved in regulation of the immune reaction. Polymorphisms in this gene are associated with a reduced risk of age-related macular degeneration. The polyadenylation site of this gene is 421 bp from the 5' end of the gene for complement component 2. [provided by RefSeq, Jul 2008]

CFB Gene-Disease associations (from GenCC):

• atypical hemolytic-uremic syndrome with B factor anomaly

  Inheritance: AD, Unknown Classification: STRONG, MODERATE, LIMITED Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae)
• complement factor b deficiency

  Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics
• C3 glomerulonephritis

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ENSG00000244255 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.75).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001710.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CFB	NM_001710.6	MANE Select	c.-3G>A		5_prime_UTR	Exon 1 of 18	NP_001701.2	P00751-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CFB	ENST00000425368.7	TSL:1 MANE Select	c.-3G>A		5_prime_UTR	Exon 1 of 18	ENSP00000416561.2	P00751-1
	ENSG00000244255	ENST00000456570.5	TSL:2	c.1571-154G>A		intron	N/A	ENSP00000410815.1	B4E1Z4
	CFB	ENST00000885733.1		c.-3G>A		5_prime_UTR	Exon 1 of 18	ENSP00000555792.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000284 AC: 7 AN: 246582 AF XY: 0.0000149

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: 0.0000543

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000123 AC: 18 AN: 1460786 Hom.: 0 Cov.: 31 AF XY: 0.0000110 AC XY: 8 AN XY: 726710

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52328

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000144 AC: 16 AN: 1112006

Other (OTH) AF: 0.0000166 AC: 1 AN: 60386

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000386 Hom.: 0

Bravo AF: 0.0000113

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Atypical hemolytic-uremic syndrome with B factor anomaly (1)
-	1	-	Atypical hemolytic-uremic syndrome with B factor anomaly;C3809653:Age related macular degeneration 14;C3809950:Complement factor b deficiency (1)
-	1	-	Macular degeneration (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.75
CADD	Benign	1.4
DANN	Benign	0.78
PhyloP100		-1.8
PromoterAI		-0.11	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

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

Other links and lift over

dbSNP: rs755016493; hg19: chr6-31913996;