2-210675738-C-T

Variant names:

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1PM2PP3_StrongPP5

The NM_001875.5(CPS1):c.4172C>T(p.Thr1391Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000773 in 1,422,922 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000077 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

CPS1
NM_001875.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:3

Conservation

PhyloP100: 7.33

Variant links:

Genes affected

CPS1 (HGNC:2323): (carbamoyl-phosphate synthase 1) The mitochondrial enzyme encoded by this gene catalyzes synthesis of carbamoyl phosphate from ammonia and bicarbonate. This reaction is the first committed step of the urea cycle, which is important in the removal of excess urea from cells. The encoded protein may also represent a core mitochondrial nucleoid protein. Three transcript variants encoding different isoforms have been found for this gene. The shortest isoform may not be localized to the mitochondrion. Mutations in this gene have been associated with carbamoyl phosphate synthetase deficiency, susceptibility to persistent pulmonary hypertension, and susceptibility to venoocclusive disease after bone marrow transplantation.[provided by RefSeq, May 2010]

CPS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

PM1

In a binding_site (size 0) in uniprot entity CPSM_HUMAN

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.955

PP5

Variant 2-210675738-C-T is Pathogenic according to our data. Variant chr2-210675738-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 552749.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=2, Pathogenic=1}. Variant chr2-210675738-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CPS1	NM_001875.5 link	c.4172C>T	p.Thr1391Met	missense_variant	Exon 36 of 38	ENST00000233072.10	NP_001866.2	P31327-1A0A024R454Q6PEK7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CPS1	ENST00000233072.10 link	c.4172C>T	p.Thr1391Met	missense_variant	Exon 36 of 38	1	NM_001875.5	ENSP00000233072.5		P31327-1

Frequencies

GnomAD3 genomes

AF:

0.00

AC:

AN:

152128

Hom.:

Cov.:

FAILED QC

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:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251190

Hom.:

AF XY:

0.00000737

AC XY:

AN XY:

135772

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:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000881

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000773

AC:

AN:

1422922

Hom.:

Cov.:

AF XY:

0.00000422

AC XY:

AN XY:

710472

show subpopulations

Gnomad4 AFR exome

AF:

0.0000306

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000117

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000836

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

152128

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74320

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000474

Hom.:

Bravo

AF:

0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:4Uncertain:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Congenital hyperammonemia, type I

Pathogenic:2Uncertain:3

May 28, 2019

Mendelics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 15, 2021

Myriad Genetics, Inc.

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

NM_001875.4(CPS1):c.4172C>T(T1391M) is a missense variant classified as a variant of uncertain significance in the context of carbamoylphosphate synthetase I deficiency. T1391M has been observed in cases with relevant disease (PMID: 21120950). Functional assessments of this variant are available in the literature (PMID: 26059772). T1391M has been observed in population frequency databases (gnomAD: SAS 0.003%). In summary, there is insufficient evidence to classify NM_001875.4(CPS1):c.4172C>T(T1391M) as pathogenic or benign. Please note: this variant was assessed in the context of healthy population screening. -

Sep 01, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine with methionine at codon 1391 of the CPS1 protein (p.Thr1391Met). The threonine residue is highly conserved and there is a moderate physicochemical difference between threonine and methionine. This variant is not present in population databases (ExAC no frequency). This missense change has been observed in individual(s) with clinical features of CPS1 deficiency (Invitae). ClinVar contains an entry for this variant (Variation ID: 552749). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). Experimental studies have shown that this missense change affects CPS1 function (PMID: 26059772). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Oct 11, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CPS1 c.4172C>T (p.Thr1391Met) results in a non-conservative amino acid change located in the Methylglyoxal synthase-like domain (IPR011607) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 251190 control chromosomes. c.4172C>T has been reported in the literature in individuals affected with Carbamoylphosphate Synthetase I Deficiency with unknown genotype or no reported second variant (e.g. Haberle_2011, Diez-Fernandez_2015), and in at least one homozygous individual with biochemical clinical features of CPS1 deficiency (e.g. Makris_2021). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in 10%-<30% of normal enzyme activity (e.g. Diez-Fernandez_2015). The following publications have been ascertained in the context of this evaluation (PMID: 26059772, 21120950, 33309754). Five submitters have cited clinical-significance assessments for this variant to ClinVar after 2014, classifying the variant as pathogenic (n=1), likely pathogenic (n=1), or uncertain significance (n=3). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Mar 24, 2021

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not provided

Pathogenic:1

Jun 18, 2021

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Published functional studies demonstrate the expression of this variant decreased enzyme activity by 80%, and significantly decreased the affinity of CPS1 for its essential allosteric activator, N-acetyl-L-glutamate (Diez-Fernandez et al., 2015); Not observed at significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 27535533, 26592762, 21120950, 26059772) -

Pulmonary hypertension, neonatal, susceptibility to

Pathogenic:1

Feb 12, 2024

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.60

BayesDel_addAF

Pathogenic

0.45

BayesDel_noAF

Pathogenic

0.51

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.95

.;D;.

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Uncertain

0.95

LIST_S2

Pathogenic

0.99

D;D;D

M_CAP

Pathogenic

0.41

MetaRNN

Pathogenic

0.95

D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.5

.;H;.

PrimateAI

Uncertain

0.73

PROVEAN

Pathogenic

-5.7

D;D;D

REVEL

Pathogenic

0.91

Sift

Pathogenic

0.0

D;D;D

Sift4G

Pathogenic

0.0

D;D;D

Polyphen

1.0

.;D;.

Vest4

0.91

MutPred

0.80

.;Gain of sheet (P = 0.1208);.;

MVP

0.97

MPC

0.86

ClinPred

1.0

GERP RS

6.1

Varity_R

0.85

gMVP

0.96

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over