rs758865880

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_003937.3(KYNU):​c.468T>A​(p.Tyr156*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000573 in 1,604,298 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000058 ( 0 hom. )

Consequence

KYNU
NM_003937.3 stop_gained

Scores

2
2
3

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: -0.0400

Publications

3 publications found
Variant links:
Genes affected
KYNU (HGNC:6469): (kynureninase) Kynureninase is a pyridoxal-5'-phosphate (pyridoxal-P) dependent enzyme that catalyzes the cleavage of L-kynurenine and L-3-hydroxykynurenine into anthranilic and 3-hydroxyanthranilic acids, respectively. Kynureninase is involved in the biosynthesis of NAD cofactors from tryptophan through the kynurenine pathway. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2010]
KYNU Gene-Disease associations (from GenCC):
  • vertebral, cardiac, renal, and limb defects syndrome 2
    Inheritance: AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), ClinGen
  • encephalopathy due to hydroxykynureninuria
    Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics
  • congenital vertebral-cardiac-renal anomalies syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 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 2-142956235-T-A is Pathogenic according to our data. Variant chr2-142956235-T-A is described in ClinVar as Pathogenic. ClinVar VariationId is 403730.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KYNUNM_003937.3 linkc.468T>A p.Tyr156* stop_gained Exon 6 of 14 ENST00000264170.9 NP_003928.1 Q16719-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KYNUENST00000264170.9 linkc.468T>A p.Tyr156* stop_gained Exon 6 of 14 1 NM_003937.3 ENSP00000264170.4 Q16719-1

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152172
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:
0.0000942
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000882
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.0000719
AC:
18
AN:
250318
AF XY:
0.000111
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000159
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000578
AC:
84
AN:
1452126
Hom.:
0
Cov.:
27
AF XY:
0.0000609
AC XY:
44
AN XY:
723080
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33220
American (AMR)
AF:
0.00
AC:
0
AN:
44634
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26040
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39510
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85992
European-Finnish (FIN)
AF:
0.0000565
AC:
3
AN:
53072
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5728
European-Non Finnish (NFE)
AF:
0.0000643
AC:
71
AN:
1103872
Other (OTH)
AF:
0.000167
AC:
10
AN:
60058
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.474
Heterozygous variant carriers
0
4
7
11
14
18
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
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:
0.0000526
AC:
8
AN:
152172
Hom.:
0
Cov.:
33
AF XY:
0.0000538
AC XY:
4
AN XY:
74332
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.0000942
AC:
1
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000882
AC:
6
AN:
67994
Other (OTH)
AF:
0.000478
AC:
1
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.563
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.0000453
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.000140
AC:
17
EpiCase
AF:
0.000109
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Vertebral, cardiac, renal, and limb defects syndrome 2 Pathogenic:2
Mar 06, 2024
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

May 03, 2023
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

not provided Pathogenic:1
Nov 17, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 28792876, 24463508, 31589614, 34200361, 38698835) -

Congenital NAD deficiency disorder Pathogenic:1
Dec 23, 2016
Embryology Laboratory, Victor Chang Cardiac Research Institute
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

This variant was discovered in a North American family. The patient presented multiple congenital malformations affecting vertebrae, heart, kidney among others. This variant is a protein truncating variant and extremely rare (ExAC MAF 0.0001419). The patient is compound heterzygous for this variant and another protein truncating variant in the same KYNU gene (NM_003937.2:c.1045_1051delTTTAAGC). Her unaffected parents are heterzygous for only one variant. Enzyme assay confirmed that the protein product of this gene variant has lost enzyme activity. Mouse embryos homozygous null for Kynu presented similar phenotype as observed in the patient, and also showed reduced concentration of NAD in the embryonic tissue. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.37
D
BayesDel_noAF
Pathogenic
0.54
CADD
Pathogenic
34
DANN
Uncertain
0.99
Eigen
Benign
-0.16
Eigen_PC
Benign
-0.40
FATHMM_MKL
Uncertain
0.84
D
PhyloP100
-0.040
Vest4
0.90
GERP RS
-1.8
Mutation Taster
=0/200
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs758865880; hg19: chr2-143713804; API