12-98659309-C-T

Variant summary

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

The NM_181861.2(APAF1):c.676C>T(p.Arg226Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000684 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: APAF1 NM_181861.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.39

Genes affected

APAF1 (HGNC:576): (apoptotic peptidase activating factor 1) This gene encodes a cytoplasmic protein that initiates apoptosis. This protein contains several copies of the WD-40 domain, a caspase recruitment domain (CARD), and an ATPase domain (NB-ARC). Upon binding cytochrome c and dATP, this protein forms an oligomeric apoptosome. The apoptosome binds and cleaves caspase 9 preproprotein, releasing its mature, activated form. Activated caspase 9 stimulates the subsequent caspase cascade that commits the cell to apoptosis. Alternative splicing results in several transcript variants encoding different isoforms. [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, 0.842

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APAF1	NM_181861.2	c.676C>T	p.Arg226Cys	missense_variant	5/27	ENST00000551964.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APAF1	ENST00000551964.6	c.676C>T	p.Arg226Cys	missense_variant	5/27	1	NM_181861.2	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251490 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135918

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461888 Hom.: 0 Cov.: 32 AF XY: 0.0000110 AC XY: 8 AN XY: 727244

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.0000224

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: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

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

Jan 24, 2024

The c.676C>T (p.R226C) alteration is located in exon 5 (coding exon 4) of the APAF1 gene. This alteration results from a C to T substitution at nucleotide position 676, causing the arginine (R) at amino acid position 226 to be replaced by a cysteine (C). 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	0.25
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.22
Cadd	Pathogenic	29
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.85	D;.;.;.;.;.;.;.
Eigen	Pathogenic	0.71
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.97	D;D;D;D;.;D;.;D
M_CAP	Uncertain	0.16	D
MetaRNN	Pathogenic	0.84	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.18	D
MutationAssessor	Pathogenic	3.1	M;M;M;.;M;.;M;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-6.1	D;D;D;D;D;D;D;D
REVEL	Uncertain	0.63
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D;D
Polyphen		1.0	D;D;D;D;D;D;D;.
Vest4		0.88
MutPred		0.63		Gain of catalytic residue at L227 (P = 0.001);Gain of catalytic residue at L227 (P = 0.001);Gain of catalytic residue at L227 (P = 0.001);.;Gain of catalytic residue at L227 (P = 0.001);.;Gain of catalytic residue at L227 (P = 0.001);Gain of catalytic residue at L227 (P = 0.001);
MVP		0.92
MPC		1.1
ClinPred		0.99	D
GERP RS		5.5
Varity_R		0.73
gMVP		0.73

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: rs1465434660; hg19: chr12-99053087; COSMIC: COSV59664636;