X-38403685-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM2PM5PP3_StrongPP5

The NM_000531.6(OTC):​c.608C>T​(p.Ser203Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S203C) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 23)

Consequence

OTC
NM_000531.6 missense

Scores

12
4
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:2

Conservation

PhyloP100: 7.52
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.995
PP5
Variant X-38403685-C-T is Pathogenic according to our data. Variant chrX-38403685-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 496026.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=2, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
OTCNM_000531.6 linkc.608C>T p.Ser203Phe missense_variant 6/10 ENST00000039007.5 NP_000522.3 P00480
OTCNM_001407092.1 linkc.608C>T p.Ser203Phe missense_variant 8/12 NP_001394021.1
OTCXM_017029556.2 linkc.608C>T p.Ser203Phe missense_variant 6/9 XP_016885045.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
OTCENST00000039007.5 linkc.608C>T p.Ser203Phe missense_variant 6/101 NM_000531.6 ENSP00000039007.4 P00480
ENSG00000250349ENST00000465127.1 linkc.172-262436C>T intron_variant 5 ENSP00000417050.1 B4E171

Frequencies

GnomAD3 genomes
Cov.:
23
GnomAD4 exome
Cov.:
30
GnomAD4 genome
Cov.:
23

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:2Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Ornithine carbamoyltransferase deficiency Pathogenic:2Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingGenome-Nilou LabNov 07, 2021- -
Pathogenic, no assertion criteria providedclinical testingMolecular Genetics laboratory, Necker Hospital-1 boy with a neonatal form -
Likely pathogenic, criteria provided, single submitterclinical testingRady Children's Institute for Genomic Medicine, Rady Children's Hospital San DiegoSep 07, 2020This variant has not been previously reported or functionally characterized in the literature to our knowledge. However, a different variant affecting the same amino acid residue, c.608C>G (p.Ser203Cys), has been previously reported in an individual with Ornithine Transcarbamylase (OTC) Deficiency (PMID: 8019569). It is absent from the gnomAD population database and thus is presumed to be rare. The c.608C>T (p.Ser203Phe) variant affects a highly conserved amino acid and is predicted by multiple in silico tools to have a deleterious effect on protein function. Analysis of the parental samples was negative for the variant, indicating this variant likely occurred as a de novo event. Based on the available evidence, the c.608C>T (p.Ser203Phe) variant is classified as Likely Pathogenic. -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpNov 16, 2016Variant summary: The OTC c.608C>T (p.Ser203Phe) variant involves the alteration of a conserved nucleotide. 5/5 in silico tools predict a damaging outcome for this variant. This variant is absent in 87525 control chromosomes and has not, to our knowledge, been reported in affected individuals via publications and/or reputable databases/clinical diagnostic laboratories; nor evaluated for functional impact by in vivo/vitro studies. Because of the absence of clinical information and the lack of functional studies, the variant is classified as a variant of uncertain significance (VUS) until additional information becomes available. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
1.0
BayesDel_addAF
Pathogenic
0.72
D
BayesDel_noAF
Pathogenic
0.80
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.99
D
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
0.97
D
M_CAP
Pathogenic
0.97
D
MetaRNN
Pathogenic
1.0
D
MetaSVM
Pathogenic
0.93
D
MutationAssessor
Pathogenic
4.3
H
PrimateAI
Uncertain
0.72
T
PROVEAN
Pathogenic
-4.8
D
REVEL
Pathogenic
0.98
Sift
Uncertain
0.0010
D
Sift4G
Uncertain
0.0030
D
Polyphen
1.0
D
Vest4
0.99
MutPred
0.95
Loss of disorder (P = 0.193);
MVP
1.0
MPC
1.2
ClinPred
1.0
D
GERP RS
5.9
Varity_R
0.99
gMVP
1.0

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs72558410; hg19: chrX-38262938; API