11-116835843-G-A

Position:

• chr11-116835843-G-A

Variant summary

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

The NM_000039.3(APOA1):​c.769C>T​(p.Leu257Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,770 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. L257L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: APOA1 NM_000039.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.47

Genes affected

APOA1 (HGNC:600): (apolipoprotein A1) This gene encodes apolipoprotein A-I, which is the major protein component of high density lipoprotein (HDL) in plasma. The encoded preproprotein is proteolytically processed to generate the mature protein, which promotes cholesterol efflux from tissues to the liver for excretion, and is a cofactor for lecithin cholesterolacyltransferase (LCAT), an enzyme responsible for the formation of most plasma cholesteryl esters. This gene is closely linked with two other apolipoprotein genes on chromosome 11. Defects in this gene are associated with HDL deficiencies, including Tangier disease, and with systemic non-neuropathic amyloidosis. Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein. [provided by RefSeq, Dec 2015]

APOA1 (HGNC:):

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=0.11868936).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APOA1	NM_000039.3	c.769C>T	p.Leu257Phe	missense_variant	4/4	ENST00000236850.5	NP_000030.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APOA1	ENST00000236850.5	c.769C>T	p.Leu257Phe	missense_variant	4/4	1	NM_000039.3	ENSP00000236850.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460770 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726700

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

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.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 24, 2023

The p.L257F variant (also known as c.769C>T), located in coding exon 3 of the APOA1 gene, results from a C to T substitution at nucleotide position 769. The leucine at codon 257 is replaced by phenylalanine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.46
CADD	Benign	0.011
DANN	Benign	0.93
DEOGEN2	Benign	0.094	T;T;T;T;T
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.5
FATHMM_MKL	Benign	0.077	N
LIST_S2	Benign	0.57	.;.;T;.;T
M_CAP	Uncertain	0.088	D
MetaRNN	Benign	0.12	T;T;T;T;T
MetaSVM	Benign	-0.96	T
MutationAssessor	Benign	1.3	L;L;.;L;L
PrimateAI	Benign	0.29	T
PROVEAN	Benign	-0.87	N;N;N;N;N
REVEL	Benign	0.13
Sift	Benign	0.063	T;T;T;T;T
Sift4G	Benign	0.17	T;T;T;T;T
Polyphen		0.025	B;B;.;B;B
Vest4		0.19
MutPred		0.57		Loss of loop (P = 0.1242);Loss of loop (P = 0.1242);.;Loss of loop (P = 0.1242);Loss of loop (P = 0.1242);
MVP		0.65
MPC		0.66
ClinPred		0.062	T
GERP RS		-5.3
Varity_R		0.21
gMVP		0.34

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr11-116706559;