chr22-38736270-G-T

Position:

• chr22-38736270-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_015374.3(SUN2):​c.2151C>A​(p.His717Gln) 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 1,460,056 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: SUN2 NM_015374.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.04

Genes affected

SUN2 (HGNC:14210): (Sad1 and UNC84 domain containing 2) SUN1 (MIM 607723) and SUN2 are inner nuclear membrane (INM) proteins that play a major role in nuclear-cytoplasmic connection by formation of a 'bridge' across the nuclear envelope, known as the LINC complex, via interaction with the conserved luminal KASH domain of nesprins (e.g., SYNE1; MIM 608441) located in the outer nuclear membrane (ONM). The LINC complex provides a direct connection between the nuclear lamina and the cytoskeleton, which contributes to nuclear positioning and cellular rigidity (summary by Haque et al., 2010 [PubMed 19933576]).[supplied by OMIM, Nov 2010]

(HGNC:):

GTPBP1 (HGNC:4669): (GTP binding protein 1) This gene is upregulated by interferon-gamma and encodes a protein that is a member of the AGP11/GTPBP1 family of GTP-binding proteins. A structurally similar protein has been found in mouse, where disruption of the gene for that protein had no observable phenotype. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.16850299).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SUN2	NM_015374.3	c.2151C>A	p.His717Gln	missense_variant	18/18	ENST00000689035.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SUN2	ENST00000689035.1	c.2151C>A	p.His717Gln	missense_variant	18/18		NM_015374.3	P2
	ENST00000418803.1	n.85+1456G>T		intron_variant, non_coding_transcript_variant		5
	ENST00000420118.1	n.317+1229G>T		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1460056 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726308

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000225

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Emery-Dreifuss muscular dystrophy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 03, 2021

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with SUN2-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces histidine with glutamine at codon 717 of the SUN2 protein (p.His717Gln). The histidine residue is weakly conserved and there is a small physicochemical difference between histidine and glutamine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.51
CADD	Benign	21
DANN	Benign	0.95
DEOGEN2	Benign	0.038	T;.;T
Eigen	Benign	-0.16
Eigen_PC	Benign	-0.042
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Benign	0.71	.;T;T
M_CAP	Benign	0.0088	T
MetaRNN	Benign	0.17	T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.0	N;.;N
MutationTaster	Benign	0.99	N;N;N;N;N
PrimateAI	Uncertain	0.51	T
PROVEAN	Benign	0.44	N;N;N
REVEL	Benign	0.053
Sift	Uncertain	0.0050	D;D;D
Sift4G	Uncertain	0.017	D;D;D
Polyphen		0.46	P;.;P
Vest4		0.18
MutPred		0.23		Gain of sheet (P = 0.0477);.;Gain of sheet (P = 0.0477);
MVP		0.60
MPC		0.45
ClinPred		0.32	T
GERP RS		3.8
Varity_R		0.27
gMVP		0.32

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: rs917841252; hg19: chr22-39132275;