chr4-39459132-C-G

Position:

• chr4-39459132-C-G

Variant summary

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

The NM_006859.4(LIAS):​c.15C>G​(p.Cys5Trp) 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 1,461,636 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: LIAS NM_006859.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.11

Genes affected

LIAS (HGNC:16429): (lipoic acid synthetase) The protein encoded by this gene belongs to the biotin and lipoic acid synthetases family. Localized in the mitochondrion, this iron-sulfur enzyme catalyzes the final step in the de novo pathway for the biosynthesis of lipoic acid, a potent antioxidant. The deficient expression of this enzyme has been linked to conditions such as diabetes, atherosclerosis and neonatal-onset epilepsy. Alternative splicing occurs at this locus, and several transcript variants encoding distinct isoforms have been identified. [provided by RefSeq, Aug 2020]

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
LIAS	NM_006859.4	c.15C>G	p.Cys5Trp	missense_variant	1/11	ENST00000640888.2	NP_006850.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LIAS	ENST00000640888.2	c.15C>G	p.Cys5Trp	missense_variant	1/11	1	NM_006859.4	ENSP00000492260	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461636 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727142

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Lipoic acid synthetase deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 20, 2020

This variant is not present in population databases (ExAC no frequency). This sequence change replaces cysteine with tryptophan at codon 5 of the LIAS protein (p.Cys5Trp). The cysteine residue is moderately conserved and there is a large physicochemical difference between cysteine and tryptophan. This variant has not been reported in the literature in individuals with LIAS-related conditions. 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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.040
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.39	T;T;T;.;T;.;.;.;.
Eigen	Uncertain	0.22
Eigen_PC	Uncertain	0.27
FATHMM_MKL	Benign	0.43	N
LIST_S2	Uncertain	0.87	D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.095	D
MetaRNN	Uncertain	0.48	T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.21	T
MutationAssessor	Uncertain	2.3	M;.;.;M;.;.;M;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.56	T
PROVEAN	Benign	-1.3	.;.;.;N;N;N;N;.;.
REVEL	Uncertain	0.35
Sift	Uncertain	0.0030	.;.;.;D;D;D;D;.;.
Sift4G	Uncertain	0.0020	.;.;.;D;D;D;D;.;.
Polyphen		0.95	P;D;P;.;P;.;.;.;.
Vest4		0.56, 0.60, 0.57, 0.58
MutPred		0.33		Gain of MoRF binding (P = 5e-04);Gain of MoRF binding (P = 5e-04);Gain of MoRF binding (P = 5e-04);Gain of MoRF binding (P = 5e-04);Gain of MoRF binding (P = 5e-04);Gain of MoRF binding (P = 5e-04);Gain of MoRF binding (P = 5e-04);Gain of MoRF binding (P = 5e-04);Gain of MoRF binding (P = 5e-04);
MVP		0.88
MPC		0.72
ClinPred		0.96	D
GERP RS		4.8
Varity_R		0.87
gMVP		0.68

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: rs1473782911; hg19: chr4-39460752;