4-154744334-AC-A

Variant names:

• chr4-154744334-AC-A
• NM_004744.5:c.12delC

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_004744.5(LRAT):​c.12delC​(p.Met5CysfsTer54) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,816 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: LRAT NM_004744.5 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 2.28

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]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 17 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 4-154744334-AC-A is Pathogenic according to our data. Variant chr4-154744334-AC-A is described in ClinVar as [Pathogenic]. Clinvar id is 1073195.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr4-154744334-AC-A is described in Lovd as [Pathogenic]. Variant chr4-154744334-AC-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LRAT	NM_004744.5	c.12delC	p.Met5CysfsTer54	frameshift_variant	Exon 2 of 3	ENST00000336356.4	NP_004735.2
LRAT	NM_001301645.2	c.12delC	p.Met5CysfsTer54	frameshift_variant	Exon 2 of 3		NP_001288574.1
LRAT	XM_047416405.1	c.12delC	p.Met5CysfsTer54	frameshift_variant	Exon 2 of 3		XP_047272361.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LRAT	ENST00000336356.4	c.12delC	p.Met5CysfsTer54	frameshift_variant	Exon 2 of 3	1	NM_004744.5	ENSP00000337224.3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461816 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727198

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.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Jun 16, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This sequence change creates a premature translational stop signal (p.Met5Cysfs*54) in the LRAT gene. It is expected to result in an absent or disrupted protein product. This variant is not present in population databases (ExAC no frequency). This variant has been reported to segregate with retinitis punctata albescens in two families (PMID: 22559933). Loss-of-function variants in LRAT are known to be pathogenic (PMID: 24265693, 22559933). -

Retinal dystrophy Pathogenic:1

Jan 01, 2016

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr4-155665486;