4-73445078-G-A

Position:

• chr4-73445078-G-A

Variant summary

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

The NM_001134.3(AFP):​c.799G>A​(p.Glu267Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,702 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: AFP NM_001134.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.352

Genes affected

AFP (HGNC:317): (alpha fetoprotein) This gene encodes alpha-fetoprotein, a major plasma protein produced by the yolk sac and the liver during fetal life. Alpha-fetoprotein expression in adults is often associated with hepatocarcinoma and with teratoma, and has prognostic value for managing advanced gastric cancer. However, hereditary persistance of alpha-fetoprotein may also be found in individuals with no obvious pathology. The protein is thought to be the fetal counterpart of serum albumin, and the alpha-fetoprotein and albumin genes are present in tandem in the same transcriptional orientation on chromosome 4. Alpha-fetoprotein is found in monomeric as well as dimeric and trimeric forms, and binds copper, nickel, fatty acids and bilirubin. The level of alpha-fetoprotein in amniotic fluid is used to measure renal loss of protein to screen for spina bifida and anencephaly. [provided by RefSeq, Oct 2019]

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=0.07732776).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
AFP	NM_001134.3	c.799G>A	p.Glu267Lys	missense_variant	7/15	ENST00000395792.7	NP_001125.1
AFP	NM_001354717.2	c.325G>A	p.Glu109Lys	missense_variant	8/16		NP_001341646.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AFP	ENST00000395792.7	c.799G>A	p.Glu267Lys	missense_variant	7/15	1	NM_001134.3	ENSP00000379138.2
AFP	ENST00000226359.2	c.799G>A	p.Glu267Lys	missense_variant	7/14	5		ENSP00000226359.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461702 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 727152

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

Asia WGS AF: 0.000289 AC: 1 AN: 3478

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

Nov 13, 2024

The c.799G>A (p.E267K) alteration is located in exon 7 (coding exon 7) of the AFP gene. This alteration results from a G to A substitution at nucleotide position 799, causing the glutamic acid (E) at amino acid position 267 to be replaced by a lysine (K). 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	0.072
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.42
CADD	Benign	7.2
DANN	Benign	0.83
DEOGEN2	Benign	0.086	T;T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.16	N
LIST_S2	Benign	0.76	T;T
M_CAP	Benign	0.021	T
MetaRNN	Benign	0.077	T;T
MetaSVM	Benign	-0.99	T
MutationAssessor	Benign	0.99	L;.
PrimateAI	Benign	0.36	T
PROVEAN	Benign	-0.61	N;N
REVEL	Benign	0.11
Sift	Benign	0.44	T;T
Sift4G	Benign	0.78	T;T
Polyphen		0.026	B;.
Vest4		0.27
MutPred		0.53		Gain of ubiquitination at E267 (P = 0.0276);Gain of ubiquitination at E267 (P = 0.0276);
MVP		0.63
MPC		0.048
ClinPred		0.18	T
GERP RS		-0.79
Varity_R		0.067
gMVP		0.21

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.15		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: rs1239498606; hg19: chr4-74310795;