1-207114184-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000715.4(C4BPA):c.227C>T(p.Thr76Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,652 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: C4BPA NM_000715.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -5.36

Genes affected

C4BPA (HGNC:1325): (complement component 4 binding protein alpha) This gene encodes a member of a superfamily of proteins composed predominantly of tandemly arrayed short consensus repeats of approximately 60 amino acids. Along with a single, unique beta-chain, seven identical alpha-chains encoded by this gene assemble into the predominant isoform of C4b-binding protein, a multimeric protein that controls activation of the complement cascade through the classical pathway. The genes encoding both alpha and beta chains are located adjacent to each other on human chromosome 1 in the regulator of complement activation gene cluster. Two pseudogenes of this gene are also found in the cluster. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.094947934).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
C4BPA	NM_000715.4	c.227C>T	p.Thr76Ile	missense_variant	3/12	ENST00000367070.8
C4BPA	XM_005273251.3	c.227C>T	p.Thr76Ile	missense_variant	3/12
C4BPA	XM_005273252.5	c.227C>T	p.Thr76Ile	missense_variant	3/12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
C4BPA	ENST00000367070.8	c.227C>T	p.Thr76Ile	missense_variant	3/12	1	NM_000715.4	P1
C4BPA	ENST00000421786.5	c.227C>T	p.Thr76Ile	missense_variant	3/5	4
C4BPA	ENST00000424088.1	c.227C>T	p.Thr76Ile	missense_variant, NMD_transcript_variant	3/5	4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152164 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251284 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135806

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 SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461488 Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3 AN XY: 727058

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152164 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74332

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 30, 2022

The c.227C>T (p.T76I) alteration is located in exon 3 (coding exon 2) of the C4BPA gene. This alteration results from a C to T substitution at nucleotide position 227, causing the threonine (T) at amino acid position 76 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.094
BayesDel_addAF	Benign	-0.35	T
BayesDel_noAF	Benign	-0.65
Cadd	Benign	0.0010
Dann	Benign	0.25
DEOGEN2	Benign	0.048	T;T
Eigen	Benign	-2.1
Eigen_PC	Benign	-2.3
FATHMM_MKL	Benign	0.0016	N
LIST_S2	Benign	0.26	T;T
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.095	T;T
MetaSVM	Benign	-0.93	T
MutationAssessor	Benign	1.5	L;.
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.28	T
PROVEAN	Benign	-0.45	N;N
REVEL	Benign	0.13
Sift	Benign	0.38	T;T
Sift4G	Benign	0.52	T;T
Polyphen		0.0020	B;.
Vest4		0.064
MutPred		0.61		Loss of disorder (P = 0.0724);Loss of disorder (P = 0.0724);
MVP		0.10
MPC		0.28
ClinPred		0.051	T
GERP RS		-10
Varity_R		0.12
gMVP		0.58

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

Publications

LitVar

Other links and lift over

dbSNP: rs778061020; hg19: chr1-207287529;