chr4-39459134-G-A

Position:

• chr4-39459134-G-A

Variant summary

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

The NM_006859.4(LIAS):​c.17G>A​(p.Gly6Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000198 in 1,461,648 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 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: 0.000020 (0 hom.)
• Consequence: LIAS NM_006859.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.40

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.15080771).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LIAS	NM_006859.4	c.17G>A	p.Gly6Glu	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.17G>A	p.Gly6Glu	missense_variant	1/11	1	NM_006859.4	ENSP00000492260	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.0000198 AC: 29 AN: 1461648 Hom.: 0 Cov.: 31 AF XY: 0.0000124 AC XY: 9 AN XY: 727148

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: 0.0000261

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 27, 2022

This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 6 of the LIAS protein (p.Gly6Glu). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with LIAS-related conditions. 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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	Benign	0.094
BayesDel_addAF	Benign	-0.046	T
BayesDel_noAF	Benign	-0.30
CADD	Benign	20
DANN	Uncertain	0.98
DEOGEN2	Benign	0.32	T;T;T;.;T;.;.;.;.
Eigen	Benign	-0.11
Eigen_PC	Benign	0.0099
FATHMM_MKL	Benign	0.63	D
LIST_S2	Uncertain	0.87	D;D;D;D;D;D;D;D;D
M_CAP	Benign	0.042	D
MetaRNN	Benign	0.15	T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.76	T
MutationAssessor	Benign	1.5	L;.;.;L;.;.;L;.;.
MutationTaster	Benign	0.99	N;N;N;N
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-0.76	.;.;.;N;D;N;N;.;.
REVEL	Benign	0.11
Sift	Benign	0.061	.;.;.;T;T;T;T;.;.
Sift4G	Uncertain	0.049	.;.;.;D;T;T;T;.;.
Polyphen		0.040	B;P;B;.;B;.;.;.;.
Vest4		0.43, 0.65, 0.46, 0.45
MutPred		0.27		Gain of helix (P = 0.0082);Gain of helix (P = 0.0082);Gain of helix (P = 0.0082);Gain of helix (P = 0.0082);Gain of helix (P = 0.0082);Gain of helix (P = 0.0082);Gain of helix (P = 0.0082);Gain of helix (P = 0.0082);Gain of helix (P = 0.0082);
MVP		0.83
MPC		0.52
ClinPred		0.91	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.18
gMVP		0.47

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: rs1744293519; hg19: chr4-39460754;