10-68415060-CA-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PM4

The NM_001080449.3(DNA2):c.3161del(p.Leu1054TrpfsTer52) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 152,036 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: DNA2 NM_001080449.3 frameshift
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.20

Genes affected

DNA2 (HGNC:2939): (DNA replication helicase/nuclease 2) This gene encodes a member of the DNA2/NAM7 helicase family. The encoded protein is a conserved helicase/nuclease involved in the maintenance of mitochondrial and nuclear DNA stability. Mutations in this gene are associated with autosomal dominant progressive external ophthalmoplegia-6 (PEOA6) and Seckel syndrome 8. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Sep 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Frameshift in the end of transcript resulting in stoplost. Downstream stopcodon found after 1088 codons.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DNA2	NM_001080449.3	c.3161del	p.Leu1054TrpfsTer52	frameshift_variant	21/21	ENST00000358410.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DNA2	ENST00000358410.8	c.3161del	p.Leu1054TrpfsTer52	frameshift_variant	21/21	1	NM_001080449.3	P1
DNA2	ENST00000551118.6	c.2449del	p.Trp817GlyfsTer2	frameshift_variant	17/17	5
DNA2	ENST00000399179.6	c.*982del		3_prime_UTR_variant, NMD_transcript_variant	22/22	2

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152036 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 28

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152036 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74254

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000843 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 04, 2022

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. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. This variant has not been reported in the literature in individuals affected with DNA2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change results in a frameshift in the DNA2 gene (p.Leu1054Trpfs*52). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 7 amino acid(s) of the DNA2 protein and extend the protein by 44 additional amino acid residues. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1214955982; hg19: chr10-70174817;