dbSNP rs886037832: TWNK:p.Leu112SerfsTer3 (chr10-100988540-CT-C) – ACMG Classification: Pathogenic (11 pts)

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1PM2PP5

The NM_021830.5(TWNK):c.333delT(p.Leu112SerfsTer3) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,824 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (no stars). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TWNK
NM_021830.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic no assertion criteria provided P:1

Conservation

PhyloP100: 7.79

Publications

1 publications found

Variant links:

Genes affected

TWNK (HGNC:1160): (twinkle mtDNA helicase) This gene encodes a hexameric DNA helicase which unwinds short stretches of double-stranded DNA in the 5' to 3' direction and, along with mitochondrial single-stranded DNA binding protein and mtDNA polymerase gamma, is thought to play a key role in mtDNA replication. The protein localizes to the mitochondrial matrix and mitochondrial nucleoids. Mutations in this gene cause infantile onset spinocerebellar ataxia (IOSCA) and progressive external ophthalmoplegia (PEO) and are also associated with several mitochondrial depletion syndromes. Alternative splicing results in multiple transcript variants encoding distinct isoforms.[provided by RefSeq, Aug 2009]

TWNK Gene-Disease associations (from GenCC):

progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 3
Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
mitochondrial DNA depletion syndrome 7 (hepatocerebral type)
Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
autosomal dominant progressive external ophthalmoplegia
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
mitochondrial DNA depletion syndrome, hepatocerebrorenal form
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
Perrault syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

TWNK links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 11 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 10-100988540-CT-C is Pathogenic according to our data. Variant chr10-100988540-CT-C is described in ClinVar as [Pathogenic]. Clinvar id is 225837.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TWNK	NM_021830.5 link	c.333delT	p.Leu112SerfsTer3	frameshift_variant	Exon 1 of 5	ENST00000311916.8	NP_068602.2	Q96RR1-1E5KSY5Q9H6V3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TWNK	ENST00000311916.8 link	c.333delT	p.Leu112SerfsTer3	frameshift_variant	Exon 1 of 5	1	NM_021830.5	ENSP00000309595.2		Q96RR1-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461824

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727210

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53354

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1112010

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

LINK: link

Submissions by phenotype

Infantile onset spinocerebellar ataxia

Pathogenic:1

Mar 20, 2016

King Laboratory, University of Washington

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:research

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

PhyloP100

7.8

Mutation Taster

=1/199

disease causing (ClinVar)

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over