NM_025265.4:c.926A>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM1PP5BS1_Supporting

The NM_025265.4(TSEN2):​c.926A>G​(p.Tyr309Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000502 in 1,613,986 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: š‘“ 0.000020 ( 0 hom., cov: 31)
Exomes š‘“: 0.000053 ( 1 hom. )

Consequence

TSEN2
NM_025265.4 missense

Scores

12
6
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:3O:1

Conservation

PhyloP100: 6.42

Publications

11 publications found
Variant links:
Genes affected
TSEN2 (HGNC:28422): (tRNA splicing endonuclease subunit 2) This gene encodes one of the subunits of the tRNA splicing endonuclease. This endonuclease catalyzes the first step in RNA splicing which is the removal of introns. Mutations in this gene have been associated with pontocerebellar hypoplasia type 2. A pseudogene has been identified on chromosome 4. Multiple transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Feb 2009]
MKRN2OS (HGNC:40375): (MKRN2 opposite strand)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_025265.4
PP5
Variant 3-12516627-A-G is Pathogenic according to our data. Variant chr3-12516627-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 2125.
BS1
Variant frequency is greater than expected in population amr. GnomAdExome4 allele frequency = 0.0000534 (78/1461842) while in subpopulation AMR AF = 0.000425 (19/44724). AF 95% confidence interval is 0.000277. There are 1 homozygotes in GnomAdExome4. There are 44 alleles in the male GnomAdExome4 subpopulation. Median coverage is 31. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TSEN2NM_025265.4 linkc.926A>G p.Tyr309Cys missense_variant Exon 7 of 12 ENST00000284995.11 NP_079541.1 Q8NCE0-1A0A024R2G3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TSEN2ENST00000284995.11 linkc.926A>G p.Tyr309Cys missense_variant Exon 7 of 12 1 NM_025265.4 ENSP00000284995.6 Q8NCE0-1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152028
Hom.:
0
Cov.:
31
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000139
AC:
35
AN:
251398
AF XY:
0.000103
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000607
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00163
GnomAD4 exome
AF:
0.0000534
AC:
78
AN:
1461842
Hom.:
1
Cov.:
31
AF XY:
0.0000605
AC XY:
44
AN XY:
727220
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
American (AMR)
AF:
0.000425
AC:
19
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39686
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53402
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000414
AC:
46
AN:
1111998
Other (OTH)
AF:
0.000132
AC:
8
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.432
Heterozygous variant carriers
0
4
8
13
17
21
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
4
8
12
16
20
<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:
0.0000197
AC:
3
AN:
152144
Hom.:
0
Cov.:
31
AF XY:
0.0000269
AC XY:
2
AN XY:
74380
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41502
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5166
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10570
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68016
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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:
0.0000416
Hom.:
0
Bravo
AF:
0.0000567
ExAC
AF:
0.000165
AC:
20
Asia WGS
AF:
0.000289
AC:
1
AN:
3478
EpiCase
AF:
0.000164
EpiControl
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:4Uncertain:3Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Pontocerebellar hypoplasia type 2B Pathogenic:3Uncertain:1Other:1
Dec 18, 2017
Genomic Research Center, Shahid Beheshti University of Medical Sciences
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
GeneReviews
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

Jan 01, 2011
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

-
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 12, 2022
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

- -

not provided Uncertain:2
May 10, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Observed with a second TSEN2 variant in a patient with pontocerebellar hypoplasia, but it is not known whether the variants occurred on the same (in cis) or on different (in trans) chromosomes (PMID: 20952379); Published functional studies suggest Y309C affects thermal stability (PMID: 34584079); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 20952379, 18711368, 34584079, 38347586) -

Aug 09, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 309 of the TSEN2 protein (p.Tyr309Cys). This variant is present in population databases (rs113994149, gnomAD 0.06%), and has an allele count higher than expected for a pathogenic variant. This missense change has been observed in individual(s) with pontocerebellar hypoplasias (PMID: 18711368, 20952379). ClinVar contains an entry for this variant (Variation ID: 2125). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -

Pontoneocerebellar hypoplasia Pathogenic:1
Jan 09, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TSEN2 c.926A>G (p.Tyr309Cys) results in a non-conservative amino acid change located in the tRNA intron endonuclease, N-terminal domain (IPR006678) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. Multiple sequence alignment of human TSEN2 with the corresponding sequences of a broad range of other organisms showed that the Tyr309 position is strictly conserved (tyrosine or phenylalanine) within eukaryotic organisms (Budde_2008). The variant allele was found at a frequency of 0.00014 in 251398 control chromosomes in the gnomAD database, including 1 homozygote. This frequency is not significantly higher than estimated for a pathogenic variant in TSEN2 causing Pontocerebellar Hypoplasia, Type 2B (0.00014 vs 0.0011), allowing no conclusion about variant significance. Moreover, the single homozygote observed in gnomAD database has been reported as not a true homozygote due to one read supporting a reference base (Tarailo-Graovac_2017). c.926A>G has been reported in the literature as a homozygous and compound heterozygous genotype in individuals affected with Pontocerebellar Hypoplasia, Type 2B (example, Budde_2008, Namavar_2011). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as pathogenic and one laboratory classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.57
BayesDel_addAF
Pathogenic
0.16
D
BayesDel_noAF
Pathogenic
0.36
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.84
D;.;D;.;D;.
Eigen
Pathogenic
0.81
Eigen_PC
Pathogenic
0.76
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Pathogenic
0.98
D;D;.;D;D;D
M_CAP
Uncertain
0.27
D
MetaRNN
Uncertain
0.74
D;D;D;D;D;D
MetaSVM
Uncertain
0.58
D
MutationAssessor
Pathogenic
3.2
.;.;M;.;M;.
PhyloP100
6.4
PrimateAI
Uncertain
0.73
T
PROVEAN
Pathogenic
-8.6
D;D;D;D;D;D
REVEL
Pathogenic
0.83
Sift
Pathogenic
0.0
D;D;D;D;D;D
Sift4G
Pathogenic
0.0010
D;D;D;D;D;D
Polyphen
1.0
.;.;D;.;D;D
Vest4
0.95, 0.97, 0.96, 0.98
MVP
0.98
MPC
0.25
ClinPred
0.89
D
GERP RS
5.6
Varity_R
0.89
gMVP
0.66
Mutation Taster
=54/46
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
Splicevardb
2.0
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

Other links and lift over

dbSNP: rs113994149; hg19: chr3-12558126; API