rs1555620800

Variant names:

• chr17-44007592-T-A
• rs1555620800
• NM_153006.3:c.1270T>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_153006.3(NAGS):​c.1270T>A​(p.Tyr424Asn) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000131 in 152,158 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 32)
• Consequence: NAGS NM_153006.3 missense, splice_region
• Scores: Splicing: ADA: 0.7388
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 5.21
• Publications: 1 publications found

Genes affected

NAGS (HGNC:17996): (N-acetylglutamate synthase) The N-acetylglutamate synthase gene encodes a mitochondrial enzyme that catalyzes the formation of N-acetylglutamate (NAG) from glutamate and acetyl coenzyme-A. NAG is a cofactor of carbamyl phosphate synthetase I (CPSI), the first enzyme of the urea cycle in mammals. This gene may regulate ureagenesis by altering NAG availability and, thereby, CPSI activity. Deficiencies in N-acetylglutamate synthase have been associated with hyperammonemia. [provided by RefSeq, Jul 2008]

NAGS Gene-Disease associations (from GenCC):

• hyperammonemia due to N-acetylglutamate synthase deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen, G2P

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_153006.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.933

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_153006.3. 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
	NAGS	NM_153006.3	MANE Select	c.1270T>A	p.Tyr424Asn	missense splice_region	Exon 6 of 7	NP_694551.1	Q8N159

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NAGS	ENST00000293404.8	TSL:1 MANE Select	c.1270T>A	p.Tyr424Asn	missense splice_region	Exon 6 of 7	ENSP00000293404.2	Q8N159
	NAGS	ENST00000589767.1	TSL:2	c.1201T>A	p.Tyr401Asn	missense	Exon 6 of 7	ENSP00000465408.1	K7EK11
	NAGS	ENST00000906978.1		c.1285T>A	p.Tyr429Asn	missense splice_region	Exon 6 of 7	ENSP00000577037.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152158 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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 AF: 0.0000131 AC: 2 AN: 152158 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74338

African (AFR) AF: 0.0000241 AC: 1 AN: 41414

American (AMR) AF: 0.0000655 AC: 1 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5190

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68036

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000624 Hom.: 0

Bravo AF: 0.0000189

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	2	-	Hyperammonemia, type III (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.57
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
CADD	Pathogenic	32
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.95	D
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.73	D
MetaRNN	Pathogenic	0.93	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.4	M
PhyloP100		5.2
PrimateAI	Uncertain	0.75	T
PROVEAN	Pathogenic	-6.6	D
REVEL	Pathogenic	0.88
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.74		Loss of phosphorylation at Y424 (P = 0.0341)
MVP		0.99
MPC		2.3
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.98
gMVP		0.90

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.74
dbscSNV1_RF	Benign	0.44
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1555620800; hg19: chr17-42084960;