NM_019108.4:c.1340-5T>C

Variant names:

• chr19-43733007-A-G
• rs750812146
• NM_019108.4:c.1340-5T>C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_019108.4(SMG9):​c.1340-5T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000498 in 1,606,678 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 predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: SMG9 NM_019108.4 splice_region, intron
• Scores: Splicing: ADA: 0.0009464
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0640
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• heart and brain malformation syndrome

  Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.77).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_019108.4. 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
	SMG9	NM_019108.4	MANE Select	c.1340-5T>C		splice_region intron	N/A	NP_061981.2	Q9H0W8-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMG9	ENST00000270066.11	TSL:1 MANE Select	c.1340-5T>C		splice_region intron	N/A	ENSP00000270066.6	Q9H0W8-1
	SMG9	ENST00000892518.1		c.1433-5T>C		splice_region intron	N/A	ENSP00000562577.1
	SMG9	ENST00000892519.1		c.1406-5T>C		splice_region intron	N/A	ENSP00000562578.1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152058 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000242

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

GnomAD2 exomes AF: 0.0000123 AC: 3 AN: 243388 AF XY: 0.0000152

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000273

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000481 AC: 7 AN: 1454620 Hom.: 0 Cov.: 31 AF XY: 0.00000553 AC XY: 4 AN XY: 723388

African (AFR) AF: 0.00 AC: 0 AN: 33206

American (AMR) AF: 0.00 AC: 0 AN: 43514

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25486

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 85532

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53126

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5660

European-Non Finnish (NFE) AF: 0.00000632 AC: 7 AN: 1108432

Other (OTH) AF: 0.00 AC: 0 AN: 60008

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152058 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74278

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

African (AFR) AF: 0.0000242 AC: 1 AN: 41390

American (AMR) AF: 0.00 AC: 0 AN: 15258

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5186

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10610

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68004

Other (OTH) AF: 0.00 AC: 0 AN: 2090

⚠️ 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

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.77
CADD	Benign	6.4
DANN	Benign	0.68
PhyloP100		-0.064

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00095
dbscSNV1_RF	Benign	0.21
SpliceAI score (max)		0.020		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: rs750812146; hg19: chr19-44237159;