rs72556288

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000531.6(OTC):​c.540+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000092 in 1,087,400 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: not found (cov: 23)
Exomes 𝑓: 9.2e-7 ( 0 hom. 0 hem. )

Consequence

OTC
NM_000531.6 splice_donor, intron

Scores

3
1
1
Splicing: ADA: 1.000
2

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:2

Conservation

PhyloP100: 9.30
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant X-38401429-G-A is Pathogenic according to our data. Variant chrX-38401429-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 1458773.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
OTCNM_000531.6 linkc.540+1G>A splice_donor_variant, intron_variant Intron 5 of 9 ENST00000039007.5 NP_000522.3 P00480
OTCNM_001407092.1 linkc.540+1G>A splice_donor_variant, intron_variant Intron 7 of 11 NP_001394021.1
OTCXM_017029556.2 linkc.540+1G>A splice_donor_variant, intron_variant Intron 5 of 8 XP_016885045.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
OTCENST00000039007.5 linkc.540+1G>A splice_donor_variant, intron_variant Intron 5 of 9 1 NM_000531.6 ENSP00000039007.4 P00480
ENSG00000250349ENST00000465127.1 linkc.172-264692G>A intron_variant Intron 3 of 8 5 ENSP00000417050.1 B4E171
OTCENST00000488812.1 linkn.577+1G>A splice_donor_variant, intron_variant Intron 5 of 5 5
OTCENST00000643344.1 linkn.*290+1G>A splice_donor_variant, intron_variant Intron 6 of 10 ENSP00000496606.1 A0A2R8Y829

Frequencies

GnomAD3 genomes
Cov.:
23
GnomAD3 exomes
AF:
0.00000546
AC:
1
AN:
183032
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
67558
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 SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000122
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
9.20e-7
AC:
1
AN:
1087400
Hom.:
0
Cov.:
28
AF XY:
0.00
AC XY:
0
AN XY:
353132
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:
0.00000120
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
23

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Ornithine carbamoyltransferase deficiency Pathogenic:2
Aug 03, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This sequence change affects a donor splice site in intron 5 of the OTC gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in OTC are known to be pathogenic (PMID: 10946359, 16786505). This variant is not present in population databases (ExAC no frequency). Disruption of this splice site has been observed in individual(s) with ornithine transcarbamylase deficiency (PMID: 8566955, 31426867). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. -

Feb 03, 2023
Revvity Omics, Revvity
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.74
D
BayesDel_noAF
Pathogenic
0.38
CADD
Pathogenic
31
DANN
Uncertain
1.0
FATHMM_MKL
Pathogenic
1.0
D
GERP RS
5.8

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.95
SpliceAI score (max)
1.0
Details are displayed if max score is > 0.2
DS_DL_spliceai
1.0
Position offset: -1

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: rs72556288; hg19: chrX-38260682; API