chr10-100989213-C-G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM2PM5PP3_Moderate

The NM_021830.5(TWNK):ā€‹c.1003C>Gā€‹(p.Pro335Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,870 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P335T) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 33)
Exomes š‘“: 6.8e-7 ( 0 hom. )

Consequence

TWNK
NM_021830.5 missense

Scores

9
6
3

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 7.87
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PM1
In a region_of_interest Required for hexamers formation and DNA helicase activity (size 251) in uniprot entity PEO1_HUMAN there are 38 pathogenic changes around while only 8 benign (83%) in NM_021830.5
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr10-100989213-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 426102.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Uncertain_significance=1}.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.908

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
TWNKNM_021830.5 linkuse as main transcriptc.1003C>G p.Pro335Ala missense_variant 1/5 ENST00000311916.8

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
TWNKENST00000311916.8 linkuse as main transcriptc.1003C>G p.Pro335Ala missense_variant 1/51 NM_021830.5 P1Q96RR1-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461870
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
727236
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
8.99e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
33
Bravo
AF:
0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.24
BayesDel_addAF
Pathogenic
0.26
D
BayesDel_noAF
Pathogenic
0.14
CADD
Uncertain
24
DANN
Uncertain
0.99
DEOGEN2
Benign
0.41
T;.
Eigen
Uncertain
0.65
Eigen_PC
Uncertain
0.61
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.88
D;D
M_CAP
Pathogenic
0.58
D
MetaRNN
Pathogenic
0.91
D;D
MetaSVM
Pathogenic
0.92
D
MutationAssessor
Pathogenic
3.0
M;M
MutationTaster
Benign
1.0
D;D
PROVEAN
Pathogenic
-6.4
D;D
REVEL
Pathogenic
0.71
Sift
Uncertain
0.023
D;D
Sift4G
Uncertain
0.020
D;D
Polyphen
0.98
D;D
Vest4
0.67
MutPred
0.67
Gain of helix (P = 0.0128);Gain of helix (P = 0.0128);
MVP
0.92
MPC
1.3
ClinPred
0.99
D
GERP RS
5.9
Varity_R
0.39
gMVP
0.79

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

LitVar

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

Other links and lift over

dbSNP: rs1554887028; hg19: chr10-102748970; API