4-177433250-C-T

Variant names:

• chr4-177433250-C-T
• rs121964905
• NM_000027.4:c.904G>A

Variant summary

Our verdict is Pathogenic. The variant received 15 ACMG points: 15P and 0B. PS1_Very_Strong PM2 PP3_Strong PP5

The NM_000027.4(AGA):​c.904G>A​(p.Gly302Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,768 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 Pathogenic (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Synonymous variant affecting the same amino acid position (i.e. G302G) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: AGA NM_000027.4 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.34
• Publications: 5 publications found

Genes affected

AGA (HGNC:318): (aspartylglucosaminidase) This gene encodes a member of the N-terminal nucleophile (Ntn) hydrolase family of proteins. The encoded preproprotein is proteolytically processed to generate alpha and beta chains that comprise the mature enzyme. This enzyme is involved in the catabolism of N-linked oligosaccharides of glycoproteins. It cleaves asparagine from N-acetylglucosamines as one of the final steps in the lysosomal breakdown of glycoproteins. Mutations in this gene are associated with the lysosomal storage disease aspartylglycosaminuria that results in progressive neurodegeneration. Alternative splicing results in multiple transcript variants, at least one of which encodes an isoform that is subject to proteolytic processing. [provided by RefSeq, Nov 2015]

AGA Gene-Disease associations (from GenCC):

• aspartylglucosaminuria

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, G2P, Orphanet, Myriad Women’s Health, Labcorp Genetics (formerly Invitae), Genomics England PanelApp

ACMG classification

Our verdict: Pathogenic. The variant received 15 ACMG points.

• PS1: Transcript NM_000027.4 (AGA) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994
• PP5: Variant 4-177433250-C-T is Pathogenic according to our data. Variant chr4-177433250-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 220.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AGA	NM_000027.4	c.904G>A	p.Gly302Arg	missense_variant	Exon 8 of 9	ENST00000264595.7	NP_000018.2
AGA	NM_001171988.2	c.874G>A	p.Gly292Arg	missense_variant	Exon 8 of 9		NP_001165459.1
AGA	NR_033655.2	n.890G>A		non_coding_transcript_exon_variant	Exon 7 of 8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AGA	ENST00000264595.7	c.904G>A	p.Gly302Arg	missense_variant	Exon 8 of 9	1	NM_000027.4	ENSP00000264595.2
AGA	ENST00000502310.5	c.*11G>A		downstream_gene_variant		5		ENSP00000423798.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461768 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727176

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

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39656

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111970

Other (OTH) AF: 0.0000166 AC: 1 AN: 60390

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0000343967), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Aspartylglucosaminuria Pathogenic:1

Dec 15, 1991

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.88
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.89	D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.50	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.0	H
PhyloP100		7.3
PrimateAI	Uncertain	0.62	T
PROVEAN	Pathogenic	-7.3	D
REVEL	Pathogenic	0.91
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.010	D
Polyphen		1.0	D
Vest4		1.0
MutPred		0.95		Gain of MoRF binding (P = 0.0475);
MVP		0.96
MPC		0.58
ClinPred		1.0	D
GERP RS		6.0
Varity_R		0.98
gMVP		0.99
Mutation Taster		=8/92	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs121964905; hg19: chr4-178354404;