rs796052702

Positions:

• chr4-39462269-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_006859.4(LIAS):​c.292C>T​(p.Arg98Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000783 in 1,404,200 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000078 (0 hom.)
• Consequence: LIAS NM_006859.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.778

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 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.869

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LIAS	NM_006859.4	c.292C>T	p.Arg98Trp	missense_variant	3/11	ENST00000640888.2	NP_006850.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LIAS	ENST00000640888.2	c.292C>T	p.Arg98Trp	missense_variant	3/11	1	NM_006859.4	ENSP00000492260	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000783 AC: 11 AN: 1404200 Hom.: 0 Cov.: 25 AF XY: 0.00000859 AC XY: 6 AN XY: 698588

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: 0.0000102

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

Lipoic acid synthetase deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 12, 2022

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 98 of the LIAS protein (p.Arg98Trp). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with LIAS-related conditions. ClinVar contains an entry for this variant (Variation ID: 206045). 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 disruptive. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.66
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D;D;.;.;.;.
Eigen	Uncertain	0.43
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Uncertain	0.83	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D;D
M_CAP	Pathogenic	0.54	D
MetaRNN	Pathogenic	0.87	D;D;D;D;D;D
MetaSVM	Uncertain	0.50	D
MutationAssessor	Pathogenic	3.5	H;.;H;H;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.76	T
PROVEAN	Pathogenic	-7.3	.;.;D;D;.;.
REVEL	Pathogenic	0.81
Sift	Pathogenic	0.0	.;.;D;D;.;.
Sift4G	Pathogenic	0.0	.;.;D;D;.;.
Polyphen		1.0	D;D;.;.;.;.
Vest4		0.71, 0.75
MutPred		0.48		Loss of disorder (P = 0.0249);Loss of disorder (P = 0.0249);Loss of disorder (P = 0.0249);Loss of disorder (P = 0.0249);Loss of disorder (P = 0.0249);.;
MVP		0.94
ClinPred		0.99	D
GERP RS		4.1
Varity_R		0.83
gMVP		0.84

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.13		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: rs796052702; hg19: chr4-39463889;