2-210594611-G-C

Variant names:

• chr2-210594611-G-C
• rs1275489342
• NM_001875.5:c.1263+5G>C

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2 PP3_Strong PP5_Very_Strong

The NM_001875.5(CPS1):​c.1263+5G>C variant causes a splice region, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 151,874 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: CPS1 NM_001875.5 splice_region, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.66

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]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 2-210594611-G-C is Pathogenic according to our data. Variant chr2-210594611-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 556714.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-210594611-G-C is described in Lovd as [Pathogenic]. Variant chr2-210594611-G-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CPS1	NM_001875.5	c.1263+5G>C		splice_region_variant, intron_variant	Intron 12 of 37	ENST00000233072.10	NP_001866.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CPS1	ENST00000233072.10	c.1263+5G>C		splice_region_variant, intron_variant	Intron 12 of 37	1	NM_001875.5	ENSP00000233072.5

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151874 Hom.: 0 Cov.: 32

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 27

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151874 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74134

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: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

EpiCase AF: 0.0000546

EpiControl AF: 0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Congenital hyperammonemia, type I Pathogenic:2

Feb 13, 2018

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 25, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. ClinVar contains an entry for this variant (Variation ID: 556714). This variant has been observed in individuals with carbamoyl phosphate synthetase I deficiency (PMID: 15164414, 21120950, 22173106, 28526534). This variant is not present in population databases (gnomAD no frequency). This sequence change falls in intron 12 of the CPS1 gene. It does not directly change the encoded amino acid sequence of the CPS1 protein. It affects a nucleotide within the consensus splice site. -

Pulmonary hypertension, neonatal, susceptibility to Pathogenic:1

Feb 29, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.31
CADD	Benign	18
DANN	Benign	0.94
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.91
SpliceAI score (max)		0.88		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.88		Position offset: -5

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1275489342; hg19: chr2-211459335;