chr22-38736367-GC-G

Variant names:

• chr22-38736367-GC-G
• rs1264903354
• NM_015374.3:c.2053delG

Variant summary

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

The NM_015374.3(SUN2):​c.2053delG​(p.Ala685ProfsTer11) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,206 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: SUN2 NM_015374.3 frameshift
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.899

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]

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]

ENSG00000230149 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SUN2	NM_015374.3	c.2053delG	p.Ala685ProfsTer11	frameshift_variant	Exon 18 of 18	ENST00000689035.1	NP_056189.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SUN2	ENST00000689035.1	c.2053delG	p.Ala685ProfsTer11	frameshift_variant	Exon 18 of 18		NM_015374.3	ENSP00000508608.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152206 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

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

GnomAD4 exome Cov.: 30

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152206 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74360

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

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

Mar 14, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in SUN2 cause disease. 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. This variant has not been reported in the literature in individuals with SUN2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change results in a premature translational stop signal in the SUN2 gene (p.Ala685Profs*11). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 33 amino acids of the SUN2 protein. -

Computational scores

Source: dbNSFP v4.3

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: rs1264903354; hg19: chr22-39132372;