rs886046623

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_021830.5(TWNK):​c.-644A>C variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000005 in 1,398,662 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000040 ( 0 hom. )

Consequence

TWNK
NM_021830.5 5_prime_UTR_premature_start_codon_gain

Scores

2

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 0.279

Publications

0 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]
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]

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ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.95).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_021830.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TWNK
NM_021830.5
MANE Select
c.-644A>C
5_prime_UTR_premature_start_codon_gain
Exon 1 of 5NP_068602.2
TWNK
NM_021830.5
MANE Select
c.-644A>C
5_prime_UTR
Exon 1 of 5NP_068602.2
TWNK
NM_001163812.2
c.-644A>C
5_prime_UTR_premature_start_codon_gain
Exon 1 of 5NP_001157284.1Q96RR1-2

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TWNK
ENST00000311916.8
TSL:1 MANE Select
c.-644A>C
5_prime_UTR_premature_start_codon_gain
Exon 1 of 5ENSP00000309595.2Q96RR1-1
TWNK
ENST00000370228.2
TSL:1
c.-644A>C
5_prime_UTR_premature_start_codon_gain
Exon 1 of 5ENSP00000359248.1Q96RR1-2
TWNK
ENST00000311916.8
TSL:1 MANE Select
c.-644A>C
5_prime_UTR
Exon 1 of 5ENSP00000309595.2Q96RR1-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152176
Hom.:
0
Cov.:
33
show subpopulations
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000401
AC:
5
AN:
1246486
Hom.:
0
Cov.:
20
AF XY:
0.00000328
AC XY:
2
AN XY:
610122
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
28126
American (AMR)
AF:
0.0000413
AC:
1
AN:
24224
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
19614
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35674
South Asian (SAS)
AF:
0.00
AC:
0
AN:
65356
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
32346
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
3544
European-Non Finnish (NFE)
AF:
0.00000304
AC:
3
AN:
985314
Other (OTH)
AF:
0.0000191
AC:
1
AN:
52288
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.555
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152176
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74348
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41442
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000151

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.95
CADD
Benign
9.4
DANN
Benign
0.49
PhyloP100
0.28
PromoterAI
0.33
Neutral

Splicing

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

Publications

Other links and lift over

dbSNP: rs886046623; hg19: chr10-102747324; API