9-128633839-TGCCCTGG-T

Variant names:

• chr9-128633839-TGCCCTGG-T
• NM_052844.4:c.1509_1515delCCAGGGC

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_052844.4(DYNC2I2):​c.1509_1515delCCAGGGC​(p.Gly505fs) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000753 in 1,461,268 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: DYNC2I2 NM_052844.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.37
• Publications: 0 publications found

Genes affected

DYNC2I2 (HGNC:28296): (dynein 2 intermediate chain 2) This gene encodes a member of the WD repeat protein family. WD repeats are minimally conserved regions of approximately 40 amino acids typically bracketed by gly-his and trp-asp (GH-WD), which may facilitate formation of heterotrimeric or multiprotein complexes. Members of this family are involved in a variety of cellular processes, including cell cycle progression, signal transduction, apoptosis, and gene regulation. Defects in this gene are a cause of short-rib thoracic dysplasia 11 with or without polydactyly. [provided by RefSeq, Mar 2014]

SPTAN1 (HGNC:11273): (spectrin alpha, non-erythrocytic 1) Spectrins are a family of filamentous cytoskeletal proteins that function as essential scaffold proteins that stabilize the plasma membrane and organize intracellular organelles. Spectrins are composed of alpha and beta dimers that associate to form tetramers linked in a head-to-head arrangement. This gene encodes an alpha spectrin that is specifically expressed in nonerythrocytic cells. The encoded protein has been implicated in other cellular functions including DNA repair and cell cycle regulation. Mutations in this gene are the cause of early infantile epileptic encephalopathy-5. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Sep 2010]

SPTAN1 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 5

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine
• genetic developmental and epileptic encephalopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• infantile spasms

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 9-128633839-TGCCCTGG-T is Pathogenic according to our data. Variant chr9-128633839-TGCCCTGG-T is described in ClinVar as [Pathogenic]. Clinvar id is 2872998.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DYNC2I2	NM_052844.4	c.1509_1515delCCAGGGC	p.Gly505fs	frameshift_variant	Exon 9 of 9	ENST00000372715.7	NP_443076.2
SPTAN1	NM_001130438.3	c.*506_*512delGCCCTGG		downstream_gene_variant		ENST00000372739.7	NP_001123910.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DYNC2I2	ENST00000372715.7	c.1509_1515delCCAGGGC	p.Gly505fs	frameshift_variant	Exon 9 of 9	1	NM_052844.4	ENSP00000361800.2
SPTAN1	ENST00000372739.7	c.*506_*512delGCCCTGG		downstream_gene_variant		1	NM_001130438.3	ENSP00000361824.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000753 AC: 11 AN: 1461268 Hom.: 0 AF XY: 0.00000963 AC XY: 7 AN XY: 726952

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52804

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000899 AC: 10 AN: 1112010

Other (OTH) AF: 0.0000166 AC: 1 AN: 60390

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Short-rib thoracic dysplasia 11 with or without polydactyly Pathogenic:1

Nov 19, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the WDR34 protein in which other variant(s) (p.Thr514Argfs*11) have been determined to be pathogenic (PMID: 24183451). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. This variant has not been reported in the literature in individuals affected with WDR34-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gly505*) in the WDR34 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 32 amino acid(s) of the WDR34 protein. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.4

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

hg19: chr9-131396118;