NM_012318.3:c.2094delA

Variant names:

• chr4-1814549-CT-C
• rs2108832976
• NM_012318.3:c.2094delA

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The NM_012318.3(LETM1):​c.2094delA​(p.Asp699MetfsTer13) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,356 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: LETM1 NM_012318.3 frameshift
• Clinical Significance: Pathogenic no assertion criteria provided P:2
• Conservation: PhyloP100: 0.281
• Publications: 0 publications found

Genes affected

LETM1 (HGNC:6556): (leucine zipper and EF-hand containing transmembrane protein 1) This gene encodes a protein that is localized to the inner mitochondrial membrane. The protein functions to maintain the mitochondrial tubular shapes and is required for normal mitochondrial morphology and cellular viability. Mutations in this gene cause Wolf-Hirschhorn syndrome, a complex malformation syndrome caused by the deletion of parts of the distal short arm of chromosome 4. Related pseudogenes have been identified on chromosomes 8, 15 and 19. [provided by RefSeq, Oct 2009]

LETM1 Gene-Disease associations (from GenCC):

• neurodegeneration, childhood-onset, with multisystem involvement due to mitochondrial dysfunction

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0568 CDS is truncated, and there are 1 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 4-1814549-CT-C is Pathogenic according to our data. Variant chr4-1814549-CT-C is described in ClinVar as Pathogenic. ClinVar VariationId is 1300218.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_012318.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LETM1	NM_012318.3	MANE Select	c.2094delA	p.Asp699MetfsTer13	frameshift	Exon 14 of 14	NP_036450.1	O95202-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LETM1	ENST00000302787.3	TSL:1 MANE Select	c.2094delA	p.Asp699MetfsTer13	frameshift	Exon 14 of 14	ENSP00000305653.2	O95202-1
	LETM1	ENST00000872452.1		c.2511delA	p.Asp838MetfsTer13	frameshift	Exon 14 of 14	ENSP00000542511.1
	LETM1	ENST00000872451.1		c.2112delA	p.Asp705MetfsTer13	frameshift	Exon 14 of 14	ENSP00000542510.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461356 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 726942

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44680

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26120

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86142

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53340

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111772

Other (OTH) AF: 0.00 AC: 0 AN: 60366

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 34

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	LETM1-associated clinical spectrum with predominant nervous system involvement (1)
1	-	-	Neurodegeneration, childhood-onset, with multisystem involvement due to mitochondrial dysfunction (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.28

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.14		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs2108832976; hg19: chr4-1816276;