Genetic Variant SMG9:p.Ala499Thr (chr19-43731664-C-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_019108.4(SMG9):c.1495G>A(p.Ala499Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000558 in 1,614,116 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

SMG9
NM_019108.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.37

Variant links:

Genes affected

SMG9 (HGNC:25763): (SMG9 nonsense mediated mRNA decay factor) This gene encodes a regulatory subunit of the SMG1 complex, which plays a critical role in nonsense-mediated mRNA decay (NMD). Binding of the encoded protein to the SMG1 complex kinase scaffold protein results in the inhibition of its kinase activity. Mutations in this gene cause a multiple congenital anomaly syndrome in human patients, characterized by brain malformation, congenital heart disease and other features. [provided by RefSeq, Jul 2016]

SMG9 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMG9	NM_019108.4 link	c.1495G>A	p.Ala499Thr	missense_variant	Exon 14 of 14	ENST00000270066.11	NP_061981.2	Q9H0W8-1A0A024R0Q0

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMG9	ENST00000270066.11 link	c.1495G>A	p.Ala499Thr	missense_variant	Exon 14 of 14	1	NM_019108.4	ENSP00000270066.6		Q9H0W8-1
SMG9	ENST00000600097.1 link	n.264G>A		non_coding_transcript_exon_variant	Exon 2 of 2	2

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152250

Hom.:

Cov.:

show subpopulations

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:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000797

AC:

AN:

251000

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135682

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:

0.00000883

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000547

AC:

AN:

1461866

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727234

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000464

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152250

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74386

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

ExAC

AF:

0.0000247

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Dec 25, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1495G>A (p.A499T) alteration is located in exon 14 (coding exon 13) of the SMG9 gene. This alteration results from a G to A substitution at nucleotide position 1495, causing the alanine (A) at amino acid position 499 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.92

BayesDel_addAF

Uncertain

0.066

BayesDel_noAF

Uncertain

-0.050

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.089

Eigen

Uncertain

0.61

Eigen_PC

Uncertain

0.63

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.93

M_CAP

Benign

0.0075

MetaRNN

Uncertain

0.59

MetaSVM

Benign

-0.54

MutationAssessor

Uncertain

2.4

PrimateAI

Pathogenic

0.81

PROVEAN

Benign

-2.0

REVEL

Benign

0.15

Sift

Uncertain

0.018

Sift4G

Uncertain

0.020

Polyphen

0.99

Vest4

0.72

MutPred

0.50

Loss of helix (P = 0.0093);

MVP

0.63

MPC

1.0

ClinPred

0.95

GERP RS

5.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.0

Varity_R

0.50

gMVP

0.52

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.070

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