Genetic Variant NM_004744.5:c.46C>A (chr4-154744372-C-A) – ACMG Classification: Uncertain_significance (3 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1PM2BP4

The NM_004744.5(LRAT):c.46C>A(p.Leu16Met) 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 1,461,866 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: 31)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

LRAT
NM_004744.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.686

Variant links:

Genes affected

LRAT (HGNC:6685): (lecithin retinol acyltransferase) The protein encoded by this gene localizes to the endoplasmic reticulum, where it catalyzes the esterification of all-trans-retinol into all-trans-retinyl ester. This reaction is an important step in vitamin A metabolism in the visual system. Mutations in this gene have been associated with early-onset severe retinal dystrophy and Leber congenital amaurosis 14. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2014]

LRAT links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM1

In a chain Lecithin retinol acyltransferase (size 229) in uniprot entity LRAT_HUMAN there are 15 pathogenic changes around while only 3 benign (83%) in NM_004744.5

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.28366673).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LRAT	NM_004744.5 link	c.46C>A	p.Leu16Met	missense_variant	Exon 2 of 3	ENST00000336356.4	NP_004735.2	O95237
LRAT	NM_001301645.2 link	c.46C>A	p.Leu16Met	missense_variant	Exon 2 of 3		NP_001288574.1	O95237
LRAT	XM_047416405.1 link	c.46C>A	p.Leu16Met	missense_variant	Exon 2 of 3		XP_047272361.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LRAT	ENST00000336356.4 link	c.46C>A	p.Leu16Met	missense_variant	Exon 2 of 3	1	NM_004744.5	ENSP00000337224.3		O95237

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251412

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135904

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1461866

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727232

show subpopulations

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:

0.00000180

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Feb 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 16 of the LRAT protein (p.Leu16Met). This variant is present in population databases (rs776286118, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with LRAT-related conditions. ClinVar contains an entry for this variant (Variation ID: 1967105). 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 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

Benign

0.12

BayesDel_addAF

Benign

-0.081

BayesDel_noAF

Benign

-0.35

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.55

.;D;D

Eigen

Benign

0.014

Eigen_PC

Benign

-0.066

FATHMM_MKL

Uncertain

0.88

LIST_S2

Benign

0.66

T;.;T

M_CAP

Benign

0.050

MetaRNN

Benign

0.28

T;T;T

MetaSVM

Benign

-0.70

MutationAssessor

Uncertain

2.3

.;M;M

PrimateAI

Benign

0.47

PROVEAN

Benign

-0.86

N;N;N

REVEL

Benign

0.18

Sift

Uncertain

0.014

D;T;T

Sift4G

Uncertain

0.030

D;D;D

Polyphen

0.99

.;D;D

Vest4

0.38

MutPred

0.43

Loss of stability (P = 0.0767);Loss of stability (P = 0.0767);Loss of stability (P = 0.0767);

MVP

0.50

MPC

1.1

ClinPred

0.84

GERP RS

3.5

Varity_R

0.065

gMVP

0.75

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over