1-183517758-C-A

Variant names:

• chr1-183517758-C-A
• rs1391258803
• NM_001375584.1:c.250C>A

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_001375584.1(SMG7):​c.250C>A​(p.Arg84Arg) variant causes a synonymous change. The variant allele was found at a frequency of 0.000000684 in 1,461,774 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SMG7 NM_001375584.1 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.63
• Publications: 0 publications found

Genes affected

SMG7 (HGNC:16792): (SMG7 nonsense mediated mRNA decay factor) This gene encodes a protein that is essential for nonsense-mediated mRNA decay (NMD); a process whereby transcripts with premature termination codons are targeted for rapid degradation by a mRNA decay complex. The mRNA decay complex consists, in part, of this protein along with proteins SMG5 and UPF1. The N-terminal domain of this protein is thought to mediate its association with SMG5 or UPF1 while the C-terminal domain interacts with the mRNA decay complex. This protein may therefore couple changes in UPF1 phosphorylation state to the degradation of NMD-candidate transcripts. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Aug 2011]

SMG7 Gene-Disease associations (from GenCC):

• autoimmune disease

  Inheritance: AD Classification: NO_KNOWN Submitted by: Illumina

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.12).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001375584.1. 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
	SMG7	NM_001375584.1	MANE Select	c.250C>A	p.Arg84Arg	synonymous	Exon 4 of 23	NP_001362513.1	A0A8I5KYV3
	SMG7	NM_001350220.2		c.337C>A	p.Arg113Arg	synonymous	Exon 6 of 25	NP_001337149.1	A0A8I5KSL3
	SMG7	NM_001394133.1		c.337C>A	p.Arg113Arg	synonymous	Exon 5 of 24	NP_001381062.1	A0A8I5KSL3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMG7	ENST00000688051.1	MANE Select	c.250C>A	p.Arg84Arg	synonymous	Exon 4 of 23	ENSP00000510175.1	A0A8I5KYV3
	SMG7	ENST00000507469.5	TSL:1	c.250C>A	p.Arg84Arg	synonymous	Exon 4 of 23	ENSP00000425133.1	Q92540-4
	SMG7	ENST00000347615.6	TSL:1	c.250C>A	p.Arg84Arg	synonymous	Exon 4 of 22	ENSP00000340766.2	Q92540-1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251212 AF XY: 0.00000737

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: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461774 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727204

⚠️ 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: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111906

Other (OTH) AF: 0.00 AC: 0 AN: 60392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.12
CADD	Benign	12
DANN	Benign	0.80
PhyloP100		3.6
Mutation Taster		=65/35	polymorphism

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: rs1391258803; hg19: chr1-183486893;