chr17-82090985-G-A

Position:

• chr17-82090985-G-A

Variant summary

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

The NM_004104.5(FASN):​c.1577C>T​(p.Ala526Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 13/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: FASN NM_004104.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.43

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	Protein	UniProt
FASN	NM_004104.5	c.1577C>T	p.Ala526Val	missense_variant	10/43	ENST00000306749.4	NP_004095.4
FASN	XM_011523538.3	c.1577C>T	p.Ala526Val	missense_variant	10/43		XP_011521840.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FASN	ENST00000306749.4	c.1577C>T	p.Ala526Val	missense_variant	10/43	1	NM_004104.5	ENSP00000304592	P1
FASN	ENST00000634990.1	c.1577C>T	p.Ala526Val	missense_variant	10/43	5		ENSP00000488964

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.00000756

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

Nov 07, 2018

In summary, the available evidence is currently insufficient to determine the role of this variant 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 output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The valine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. 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 valine at codon 526 of the FASN protein (p.Ala526Val). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and valine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.089
BayesDel_addAF	Benign	-0.15	T
BayesDel_noAF	Benign	-0.45
CADD	Benign	16
DANN	Uncertain	1.0
DEOGEN2	Benign	0.39	T;.
Eigen	Benign	-0.15
Eigen_PC	Benign	-0.23
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.82	T;T
M_CAP	Benign	0.016	T
MetaRNN	Uncertain	0.57	D;D
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	0.71	N;.
MutationTaster	Benign	1.0	D
PrimateAI	Benign	0.36	T
PROVEAN	Benign	-1.7	N;.
REVEL	Benign	0.21
Sift	Uncertain	0.021	D;.
Sift4G	Benign	0.50	T;T
Polyphen		1.0	D;.
Vest4		0.41
MVP		0.54
ClinPred		0.56	D
GERP RS		3.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.29
gMVP		0.67

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: rs1449518570; hg19: chr17-80048861;