chr17-18316627-C-G

Position:

• chr17-18316627-C-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_144775.3(SMCR8):​c.838C>G​(p.Gln280Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,890 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: SMCR8 NM_144775.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.585

Genes affected

SMCR8 (HGNC:17921): (SMCR8-C9orf72 complex subunit) Enables protein kinase binding activity and protein kinase inhibitor activity. Contributes to guanyl-nucleotide exchange factor activity. Involved in negative regulation of macromolecule metabolic process; regulation of TOR signaling; and regulation of macroautophagy. Located in chromatin; cytoplasm; and nucleoplasm. Part of guanyl-nucleotide exchange factor complex. Colocalizes with Atg1/ULK1 kinase complex. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.057563305).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMCR8	NM_144775.3	c.838C>G	p.Gln280Glu	missense_variant	1/2	ENST00000406438.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMCR8	ENST00000406438.5	c.838C>G	p.Gln280Glu	missense_variant	1/2	1	NM_144775.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461890 Hom.: 0 Cov.: 39 AF XY: 0.00000413 AC XY: 3 AN XY: 727244

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000671

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

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

Jun 10, 2024

The c.838C>G (p.Q280E) alteration is located in exon 1 (coding exon 1) of the SMCR8 gene. This alteration results from a C to G substitution at nucleotide position 838, causing the glutamine (Q) at amino acid position 280 to be replaced by a glutamic acid (E). 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	Benign	0.064
BayesDel_addAF	Benign	-0.23	T
BayesDel_noAF	Benign	-0.57
CADD	Benign	5.8
DANN	Benign	0.62
DEOGEN2	Benign	0.013	T
Eigen	Benign	-0.72
Eigen_PC	Benign	-0.66
FATHMM_MKL	Benign	0.29	N
M_CAP	Benign	0.0041	T
MetaRNN	Benign	0.058	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.95	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.23	T
PROVEAN	Benign	-0.35	N
REVEL	Benign	0.074
Sift	Benign	0.55	T
Sift4G	Benign	1.0	T
Polyphen		0.020	B
Vest4		0.23
MutPred		0.079		Gain of glycosylation at S285 (P = 0.1189);
MVP		0.12
MPC		0.054
ClinPred		0.061	T
GERP RS		3.9
Varity_R		0.15
gMVP		0.31

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: rs1982300235; hg19: chr17-18219941;