chr17-82092466-C-A

Position:

• chr17-82092466-C-A

Variant summary

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

The NM_004104.5(FASN):​c.1018G>T​(p.Ala340Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000211 in 1,423,690 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: FASN NM_004104.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.83

Genes affected

FASN (HGNC:3594): (fatty acid synthase) The enzyme encoded by this gene is a multifunctional protein. Its main function is to catalyze the synthesis of palmitate from acetyl-CoA and malonyl-CoA, in the presence of NADPH, into long-chain saturated fatty acids. In some cancer cell lines, this protein has been found to be fused with estrogen receptor-alpha (ER-alpha), in which the N-terminus of FAS is fused in-frame with the C-terminus of ER-alpha. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FASN	NM_004104.5	c.1018G>T	p.Ala340Ser	missense_variant	8/43	ENST00000306749.4
FASN	XM_011523538.3	c.1018G>T	p.Ala340Ser	missense_variant	8/43

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FASN	ENST00000306749.4	c.1018G>T	p.Ala340Ser	missense_variant	8/43	1	NM_004104.5	P1
FASN	ENST00000634990.1	c.1018G>T	p.Ala340Ser	missense_variant	8/43	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000211 AC: 3 AN: 1423690 Hom.: 0 Cov.: 37 AF XY: 0.00000284 AC XY: 2 AN XY: 705274

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000274

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Epileptic encephalopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 07, 2020

In summary, this variant has uncertain impact on FASN function. The available evidence is currently insufficient to determine its role in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with FASN-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces alanine with serine at codon 340 of the FASN protein (p.Ala340Ser). The alanine residue is highly conserved and there is a moderate physicochemical difference between alanine and serine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.39
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Benign	0.26	T;.
Eigen	Benign	-0.43
Eigen_PC	Benign	-0.38
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Benign	0.012	T
MetaRNN	Uncertain	0.43	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	-1.0	N;.
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	-1.1	N;.
REVEL	Benign	0.26
Sift	Benign	0.55	T;.
Sift4G	Benign	0.83	T;T
Polyphen		0.77	P;.
Vest4		0.45
MutPred		0.76		Gain of disorder (P = 0.0332);Gain of disorder (P = 0.0332);
MVP		0.63
ClinPred		0.37	T
GERP RS		3.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.27
gMVP		0.75

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

LitVar

Other links and lift over

dbSNP: rs1469173192; hg19: chr17-80050342;