6-56640063-G-T

Variant names:

• chr6-56640063-G-T
• rs143259402
• NM_001374736.1:c.2491-6C>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001374736.1(DST):​c.2491-6C>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,740 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: DST NM_001374736.1 splice_region, intron
• Scores: Splicing: ADA: 0.006673
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.21
• Publications: 0 publications found

Genes affected

DST (HGNC:1090): (dystonin) This gene encodes a member of the plakin protein family of adhesion junction plaque proteins. Multiple alternatively spliced transcript variants encoding distinct isoforms have been found for this gene, but the full-length nature of some variants has not been defined. It has been reported that some isoforms are expressed in neural and muscle tissue, anchoring neural intermediate filaments to the actin cytoskeleton, and some isoforms are expressed in epithelial tissue, anchoring keratin-containing intermediate filaments to hemidesmosomes. Consistent with the expression, mice defective for this gene show skin blistering and neurodegeneration. [provided by RefSeq, Mar 2010]

DST Gene-Disease associations (from GenCC):

• hereditary sensory and autonomic neuropathy type 6

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: Orphanet, Ambry Genetics, G2P, ClinGen, Labcorp Genetics (formerly Invitae)
• epidermolysis bullosa simplex 3, localized or generalized intermediate, with BP230 deficiency

  Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: PanelApp Australia, Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.82).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DST	NM_001374736.1	c.2491-6C>A		splice_region_variant, intron_variant	Intron 18 of 103	ENST00000680361.1	NP_001361665.1
DST	NM_001723.7	c.880-6C>A		splice_region_variant, intron_variant	Intron 4 of 23	ENST00000370765.11	NP_001714.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DST	ENST00000680361.1	c.2491-6C>A		splice_region_variant, intron_variant	Intron 18 of 103		NM_001374736.1	ENSP00000505098.1
DST	ENST00000370765.11	c.880-6C>A		splice_region_variant, intron_variant	Intron 4 of 23	1	NM_001723.7	ENSP00000359801.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461740 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727166

⚠️ 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: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39684

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53388

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111936

Other (OTH) AF: 0.00 AC: 0 AN: 60386

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00250614), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.82
CADD	Benign	6.1
DANN	Benign	0.46
PhyloP100		1.2

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0067
dbscSNV1_RF	Benign	0.29
SpliceAI score (max)		0.16		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: rs143259402; hg19: chr6-56504861;