1-40984966-A-T

Variant names:

• chr1-40984966-A-T
• rs150868456
• NM_001905.4:c.312A>T
• CTPS1 p.Gly104Gly

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_001905.4(CTPS1):​c.312A>T​(p.Gly104Gly) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as (no stars). Synonymous variant affecting the same amino acid position (i.e. G104G) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Failed GnomAD Quality Control
• Consequence: CTPS1 NM_001905.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.0360
• Publications: 0 publications found

Genes affected

CTPS1 (HGNC:2519): (CTP synthase 1) This gene encodes an enzyme responsible for the catalytic conversion of UTP (uridine triphosphate) to CTP (cytidine triphospate). This reaction is an important step in the biosynthesis of phospholipids and nucleic acids. Activity of this proten is important in the immune system, and loss of function of this gene has been associated with immunodeficiency. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2014]

CTPS1 Gene-Disease associations (from GenCC):

• combined immunodeficiency due to CTPS1 deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001905.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CTPS1	NM_001905.4	MANE Select	c.312A>T	p.Gly104Gly	synonymous	Exon 3 of 19	NP_001896.2	P17812-1
	CTPS1	NR_125440.2		n.459A>T		non_coding_transcript_exon	Exon 3 of 18

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CTPS1	ENST00000650070.2	MANE Select	c.312A>T	p.Gly104Gly	synonymous	Exon 3 of 19	ENSP00000497602.1	P17812-1
	CTPS1	ENST00000372616.1	TSL:2	c.312A>T	p.Gly104Gly	synonymous	Exon 2 of 18	ENSP00000361699.1	P17812-1
	CTPS1	ENST00000470271.6	TSL:3	c.312A>T	p.Gly104Gly	synonymous	Exon 3 of 19	ENSP00000497901.2	P17812-1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152206 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

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

GnomAD4 exome Cov.: 30

GnomAD4 genome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000657 AC: 1 AN: 152206 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74358

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000241 AC: 1 AN: 41444

American (AMR) AF: 0.00 AC: 0 AN: 15284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68038

Other (OTH) AF: 0.00 AC: 0 AN: 2094

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.52
CADD	Benign	17
DANN	Benign	0.71
PhyloP100		0.036
Mutation Taster		=71/29	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.65		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.65		Position offset: -2

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs150868456;

hg19: chr1-41450638;