10-100987561-A-G

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_021830.5(TWNK):c.-650A>G variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00659 in 1,426,606 control chromosomes in the GnomAD database, including 42 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0044 ( 6 hom., cov: 33)

Exomes 𝑓: 0.0069 ( 36 hom. )

Consequence

TWNK
NM_021830.5 5_prime_UTR

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:3

Conservation

PhyloP100: -0.178

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 links:

MRPL43 (HGNC:14517): (mitochondrial ribosomal protein L43) Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and help in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. They have an estimated 75% protein to rRNA composition compared to prokaryotic ribosomes, where this ratio is reversed. Another difference between mammalian mitoribosomes and prokaryotic ribosomes is that the latter contain a 5S rRNA. Among different species, the proteins comprising the mitoribosome differ greatly in sequence, and sometimes in biochemical properties, which prevents easy recognition by sequence homology. This gene encodes a 39S subunit protein. This gene and the gene for a semaphorin class 4 protein (SEMA4G) overlap at map location 10q24.31 and are transcribed in opposite directions. Sequence analysis identified multiple transcript variants encoding at least four different protein isoforms. [provided by RefSeq, Jul 2008]

MRPL43 links:

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -13 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.96).

BP6

Variant 10-100987561-A-G is Benign according to our data. Variant chr10-100987561-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 298484.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Benign=2, Uncertain_significance=2}.

BS1

Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00443 (674/152310) while in subpopulation NFE AF= 0.00695 (473/68026). AF 95% confidence interval is 0.00644. There are 6 homozygotes in gnomad4. There are 304 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High Homozygotes in GnomAd at 6 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TWNK	NM_021830.5 linkuse as main transcript	c.-650A>G		5_prime_UTR_variant	1/5	ENST00000311916.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TWNK	ENST00000311916.8 linkuse as main transcript	c.-650A>G		5_prime_UTR_variant	1/5	1	NM_021830.5	P1	Q96RR1-1

Frequencies

GnomAD3 genomes

AF:

0.00443

AC:

674

AN:

152192

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00104

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00373

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000621

Gnomad FIN

AF:

0.00838

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.00695

Gnomad OTH

AF:

0.00335

GnomAD4 exome

AF:

0.00685

AC:

8731

AN:

1274296

Hom.:

Cov.:

AF XY:

0.00670

AC XY:

4183

AN XY:

623870

show subpopulations

Gnomad4 AFR exome

AF:

0.000901

Gnomad4 AMR exome

AF:

0.00358

Gnomad4 ASJ exome

AF:

0.000597

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000579

Gnomad4 FIN exome

AF:

0.00589

Gnomad4 NFE exome

AF:

0.00805

Gnomad4 OTH exome

AF:

0.00494

GnomAD4 genome

AF:

0.00443

AC:

674

AN:

152310

Hom.:

Cov.:

AF XY:

0.00408

AC XY:

304

AN XY:

74488

show subpopulations

Gnomad4 AFR

AF:

0.00103

Gnomad4 AMR

AF:

0.00372

Gnomad4 ASJ

AF:

0.000288

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000621

Gnomad4 FIN

AF:

0.00838

Gnomad4 NFE

AF:

0.00695

Gnomad4 OTH

AF:

0.00332

Alfa

AF:

0.00508

Hom.:

Bravo

AF:

0.00432

Asia WGS

AF:

0.000577

AC:

AN:

3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Autosomal recessive cerebellar ataxia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Infantile onset spinocerebellar ataxia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 3

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

not provided

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Apr 01, 2023

TWNK: BS2 -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.96

Cadd

Benign

Dann

Benign

0.63

Splicing

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over