17-2172663-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_017575.5(SMG6):c.3352G>A(p.Asp1118Asn) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,068 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: SMG6 NM_017575.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.78

Genes affected

SMG6 (HGNC:17809): (SMG6 nonsense mediated mRNA decay factor) This gene encodes a component of the telomerase ribonucleoprotein complex responsible for the replication and maintenance of chromosome ends. The encoded protein also plays a role in the nonsense-mediated mRNA decay (NMD) pathway, providing the endonuclease activity near the premature translation termination codon that is needed to initiate NMD. Alternatively spliced transcript variants encoding distinct protein isoforms have been described. [provided by RefSeq, Feb 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.27213526).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMG6	NM_017575.5	c.3352G>A	p.Asp1118Asn	missense_variant	13/19	ENST00000263073.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMG6	ENST00000263073.11	c.3352G>A	p.Asp1118Asn	missense_variant	13/19	1	NM_017575.5	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251430 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135892

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: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461068 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726836

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

Alfa AF: 0.0000611 Hom.: 0

EpiCase AF: 0.000164

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 08, 2023

The c.3352G>A (p.D1118N) alteration is located in exon 13 (coding exon 13) of the SMG6 gene. This alteration results from a G to A substitution at nucleotide position 3352, causing the aspartic acid (D) at amino acid position 1118 to be replaced by an asparagine (N). 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	Uncertain	0.35
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.47
Cadd	Uncertain	23
Dann	Uncertain	1.0
DEOGEN2	Benign	0.16	T;.;.;T
Eigen	Uncertain	0.21
Eigen_PC	Uncertain	0.38
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.86	D;.;D;D
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.27	T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.1	M;.;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-2.6	D;.;D;.
REVEL	Benign	0.10
Sift	Benign	0.060	T;.;D;.
Sift4G	Uncertain	0.019	D;D;D;D
Polyphen		0.45	B;.;.;.
Vest4		0.68
MVP		0.41
MPC		0.25
ClinPred		0.56	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.24
gMVP		0.61

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

Publications

LitVar

Other links and lift over

dbSNP: rs1227471197; hg19: chr17-2075957;