1-156154662-G-GA

Variant names:

• chr1-156154662-G-GA
• NM_022367.4:c.85dupA

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_022367.4(SEMA4A):​c.85dupA​(p.Thr29AsnfsTer21) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. T29T) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SEMA4A NM_022367.4 frameshift
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.506

Genes affected

SEMA4A (HGNC:10729): (semaphorin 4A) This gene encodes a member of the semaphorin family of soluble and transmembrane proteins. Semaphorins are involved in numerous functions, including axon guidance, morphogenesis, carcinogenesis, and immunomodulation. The encoded protein is a single-pass type I membrane protein containing an immunoglobulin-like C2-type domain, a PSI domain and a sema domain. It inhibits axonal extension by providing local signals to specify territories inaccessible for growing axons. It is an activator of T-cell-mediated immunity and suppresses vascular endothelial growth factor (VEGF)-mediated endothelial cell migration and proliferation in vitro and angiogenesis in vivo. Mutations in this gene are associated with retinal degenerative diseases including retinitis pigmentosa type 35 (RP35) and cone-rod dystrophy type 10 (CORD10). Multiple alternatively spliced transcript variants encoding different isoforms have been identified.[provided by RefSeq, Sep 2010]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 17 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SEMA4A	NM_022367.4	c.85dupA	p.Thr29AsnfsTer21	frameshift_variant	Exon 2 of 15	ENST00000368285.8	NP_071762.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SEMA4A	ENST00000368285.8	c.85dupA	p.Thr29AsnfsTer21	frameshift_variant	Exon 2 of 15	1	NM_022367.4	ENSP00000357268.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Feb 24, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 affected with SEMA4A-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Thr29Asnfs*21) in the SEMA4A gene. It is expected to result in an absent or disrupted protein product. However, the current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in SEMA4A cause disease. -

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-156124453;