chr17-82091368-G-C

Position:

• chr17-82091368-G-C

Variant summary

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

The NM_004104.5(FASN):​c.1346C>G​(p.Ala449Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,458,784 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 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)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: FASN NM_004104.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.37

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.19544291).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FASN	NM_004104.5	c.1346C>G	p.Ala449Gly	missense_variant	9/43	ENST00000306749.4	NP_004095.4
FASN	XM_011523538.3	c.1346C>G	p.Ala449Gly	missense_variant	9/43		XP_011521840.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FASN	ENST00000306749.4	c.1346C>G	p.Ala449Gly	missense_variant	9/43	1	NM_004104.5	ENSP00000304592	P1
FASN	ENST00000634990.1	c.1346C>G	p.Ala449Gly	missense_variant	9/43	5		ENSP00000488964

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1458784 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 725638

Gnomad4 AFR exome AF: 0.0000598

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

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

May 22, 2023

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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant  is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 530981). This variant has not been reported in the literature in individuals affected with FASN-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 449 of the FASN protein (p.Ala449Gly). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.31	T
BayesDel_noAF	Benign	-0.68
CADD	Benign	18
DANN	Benign	0.92
DEOGEN2	Benign	0.30	T;.
Eigen	Benign	-0.36
Eigen_PC	Benign	-0.34
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Benign	0.81	T;T
M_CAP	Benign	0.017	T
MetaRNN	Benign	0.20	T;T
MetaSVM	Benign	-0.90	T
MutationAssessor	Benign	1.5	L;.
MutationTaster	Benign	0.55	D
PrimateAI	Benign	0.36	T
PROVEAN	Benign	-1.1	N;.
REVEL	Benign	0.14
Sift	Benign	0.31	T;.
Sift4G	Benign	0.34	T;T
Polyphen		0.14	B;.
Vest4		0.23
MutPred		0.49		Loss of stability (P = 0.0255);Loss of stability (P = 0.0255);
MVP		0.44
ClinPred		0.33	T
GERP RS		4.4
Varity_R		0.33
gMVP		0.51

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: rs1025708321; hg19: chr17-80049244;