rs72556275

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1PM5PP2PP3_Strong

The NM_000531.6(OTC):​c.493G>C​(p.Asp165His) variant causes a missense change. The variant allele was found at a frequency of 0.00000332 in 1,205,362 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 2 hemizygotes in GnomAD. In-silico tool predicts a pathogenic outcome for this variant. 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. D165G) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000089 ( 0 hom., 1 hem., cov: 23)
Exomes 𝑓: 0.0000027 ( 0 hom. 1 hem. )

Consequence

OTC
NM_000531.6 missense

Scores

13
3

Clinical Significance

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

Conservation

PhyloP100: 6.52

Publications

4 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: Orphanet, Laboratory for Molecular Medicine, ClinGen, G2P, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

PM1
In a hotspot region, there are 28 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 7 uncertain in NM_000531.6
PM5
Other missense variant is known to change same aminoacid residue: Variant chrX-38401382-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 452381.
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.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.993

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.493G>Cp.Asp165His
missense
Exon 5 of 10NP_000522.3
OTC
NM_001407092.1
c.493G>Cp.Asp165His
missense
Exon 7 of 12NP_001394021.1P00480

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
OTC
ENST00000039007.5
TSL:1 MANE Select
c.493G>Cp.Asp165His
missense
Exon 5 of 10ENSP00000039007.4P00480
ENSG00000250349
ENST00000465127.1
TSL:5
c.172-264740G>C
intron
N/AENSP00000417050.1B4E171
OTC
ENST00000713758.1
c.493G>Cp.Asp165His
missense
Exon 7 of 12ENSP00000519059.1P00480

Frequencies

GnomAD3 genomes
AF:
0.00000894
AC:
1
AN:
111911
Hom.:
0
Cov.:
23
show subpopulations
Gnomad AFR
AF:
0.0000324
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000546
AC:
1
AN:
183282
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000365
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000274
AC:
3
AN:
1093451
Hom.:
0
Cov.:
28
AF XY:
0.00000279
AC XY:
1
AN XY:
358945
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000380
AC:
1
AN:
26317
American (AMR)
AF:
0.0000284
AC:
1
AN:
35204
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
19349
East Asian (EAS)
AF:
0.00
AC:
0
AN:
30175
South Asian (SAS)
AF:
0.00
AC:
0
AN:
54032
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
40525
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4126
European-Non Finnish (NFE)
AF:
0.00000119
AC:
1
AN:
837784
Other (OTH)
AF:
0.00
AC:
0
AN:
45939
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00233887), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.350
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

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:
0.00000894
AC:
1
AN:
111911
Hom.:
0
Cov.:
23
AF XY:
0.0000293
AC XY:
1
AN XY:
34087
show subpopulations
African (AFR)
AF:
0.0000324
AC:
1
AN:
30818
American (AMR)
AF:
0.00
AC:
0
AN:
10506
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
2643
East Asian (EAS)
AF:
0.00
AC:
0
AN:
3588
South Asian (SAS)
AF:
0.00
AC:
0
AN:
2662
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
6066
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
239
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
53211
Other (OTH)
AF:
0.00
AC:
0
AN:
1493
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

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

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.85
BayesDel_addAF
Pathogenic
0.60
D
BayesDel_noAF
Pathogenic
0.73
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.96
D
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.99
D
M_CAP
Pathogenic
0.92
D
MetaRNN
Pathogenic
0.99
D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.4
M
PhyloP100
6.5
PrimateAI
Uncertain
0.65
T
PROVEAN
Pathogenic
-6.2
D
REVEL
Pathogenic
0.94
Sift
Uncertain
0.016
D
Sift4G
Pathogenic
0.0010
D
Polyphen
1.0
D
Vest4
0.82
MutPred
0.93
Loss of stability (P = 0.2701)
MVP
0.98
MPC
1.3
ClinPred
0.97
D
GERP RS
6.0
Varity_R
0.95
gMVP
0.96
Mutation Taster
=25/75
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs72556275; hg19: chrX-38260634; API