rs1057515879

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 3P and 6B. PM5PP2BP4_ModerateBS2

The NM_000531.6(OTC):​c.76C>T​(p.Arg26Trp) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000261 in 1,187,958 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 11 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. 15/23 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R26P) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000027 ( 0 hom., 2 hem., cov: 23)
Exomes 𝑓: 0.000026 ( 0 hom. 9 hem. )

Consequence

OTC
NM_000531.6 missense, splice_region

Scores

4
12
Splicing: ADA: 0.0002767
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7B:2

Conservation

PhyloP100: -0.146

Publications

0 publications found
Variant links:
Genes affected
OTC (HGNC:8512): (ornithine transcarbamylase) This nuclear gene encodes a mitochondrial matrix enzyme. The encoded protein is involved in the urea cycle which functions to detoxify ammonia into urea for excretion. Mutations in this enzyme lead to ornithine transcarbamylase deficiency, which causes hyperammonemia. [provided by RefSeq, May 2022]
OTC Gene-Disease associations (from GenCC):
  • ornithine carbamoyltransferase deficiency
    Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, G2P, Laboratory for Molecular Medicine, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PM5
Other missense variant is known to change same aminoacid residue: Variant chrX-38352773-G-C is described in ClinVar as Pathogenic. ClinVar VariationId is 97319.Status of the report is no_assertion_criteria_provided, 0 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 266 curated pathogenic missense variants (we use a threshold of 10). The gene has 15 curated benign missense variants. Gene score misZ: 1.3274 (below the threshold of 3.09). Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to ornithine carbamoyltransferase deficiency.
BP4
Computational evidence support a benign effect (MetaRNN=0.1821695).
BS2
High Hemizygotes in GnomAd4 at 2 XL gene

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000531.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
OTC
NM_000531.6
MANE Select
c.76C>Tp.Arg26Trp
missense splice_region
Exon 1 of 10NP_000522.3
OTC
NM_001407092.1
c.76C>Tp.Arg26Trp
missense splice_region
Exon 3 of 12NP_001394021.1

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
OTC
ENST00000039007.5
TSL:1 MANE Select
c.76C>Tp.Arg26Trp
missense splice_region
Exon 1 of 10ENSP00000039007.4
ENSG00000250349
ENST00000465127.1
TSL:5
c.172-313349C>T
intron
N/AENSP00000417050.1
OTC
ENST00000713758.1
c.76C>Tp.Arg26Trp
missense splice_region
Exon 3 of 12ENSP00000519059.1

Frequencies

GnomAD3 genomes
AF:
0.0000268
AC:
3
AN:
112081
Hom.:
0
Cov.:
23
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:
0.00418
Gnomad NFE
AF:
0.0000376
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.0000260
AC:
28
AN:
1075824
Hom.:
0
Cov.:
26
AF XY:
0.0000263
AC XY:
9
AN XY:
342776
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
26023
American (AMR)
AF:
0.00
AC:
0
AN:
35186
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
19251
East Asian (EAS)
AF:
0.00
AC:
0
AN:
30113
South Asian (SAS)
AF:
0.0000186
AC:
1
AN:
53634
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
40468
Middle Eastern (MID)
AF:
0.000735
AC:
3
AN:
4080
European-Non Finnish (NFE)
AF:
0.0000243
AC:
20
AN:
821693
Other (OTH)
AF:
0.0000882
AC:
4
AN:
45376
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.459
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
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:
0.0000268
AC:
3
AN:
112134
Hom.:
0
Cov.:
23
AF XY:
0.0000583
AC XY:
2
AN XY:
34324
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
30875
American (AMR)
AF:
0.00
AC:
0
AN:
10555
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
2641
East Asian (EAS)
AF:
0.00
AC:
0
AN:
3586
South Asian (SAS)
AF:
0.00
AC:
0
AN:
2703
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
6092
Middle Eastern (MID)
AF:
0.00459
AC:
1
AN:
218
European-Non Finnish (NFE)
AF:
0.0000376
AC:
2
AN:
53253
Other (OTH)
AF:
0.00
AC:
0
AN:
1521
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
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 Hom
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

ClinVar

ClinVar submissions as Germline
Significance:Uncertain significance
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
6
-
Ornithine carbamoyltransferase deficiency (6)
-
1
2
not provided (3)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Benign
0.000044
T
BayesDel_noAF
Benign
-0.24
CADD
Benign
15
DANN
Benign
0.94
DEOGEN2
Uncertain
0.42
T
FATHMM_MKL
Benign
0.61
D
LIST_S2
Benign
0.66
T
M_CAP
Uncertain
0.26
D
MetaRNN
Benign
0.18
T
MetaSVM
Uncertain
0.41
D
MutationAssessor
Benign
1.4
L
PhyloP100
-0.15
PrimateAI
Benign
0.24
T
PROVEAN
Benign
-0.81
N
REVEL
Uncertain
0.37
Sift
Benign
0.086
T
Sift4G
Benign
0.20
T
Polyphen
0.0
B
Vest4
0.19
MVP
0.47
MPC
0.39
ClinPred
0.18
T
GERP RS
-0.071
PromoterAI
-0.078
Neutral
Varity_R
0.085
gMVP
0.79
Mutation Taster
=89/11
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.00028
dbscSNV1_RF
Benign
0.052
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: rs1057515879; hg19: chrX-38212025; COSMIC: COSV50000849; API