chr4-154744334-AC-A

Position:

• chr4-154744334-AC-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_004744.5(LRAT):​c.12del​(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 (★). Synonymous variant affecting the same amino acid position (i.e. N3N) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: LRAT NM_004744.5 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• 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 12 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 38 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_single_submitter, 1 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/exons	MANE	UniProt
LRAT	NM_004744.5	c.12del	p.Met5CysfsTer54	frameshift_variant	2/3	ENST00000336356.4
LRAT	NM_001301645.2	c.12del	p.Met5CysfsTer54	frameshift_variant	2/3
LRAT	XM_047416405.1	c.12del	p.Met5CysfsTer54	frameshift_variant	2/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LRAT	ENST00000336356.4	c.12del	p.Met5CysfsTer54	frameshift_variant	2/3	1	NM_004744.5	P1

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:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jun 16, 2017

For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in LRAT are known to be pathogenic (PMID: 24265693, 22559933). This variant has been reported to segregate with retinitis punctata albescens in two families (PMID: 22559933). This variant is not present in population databases (ExAC no frequency). 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. -

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;