10-100977677-A-G

Position:

• chr10-100977677-A-G

Variant summary

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

The NM_017893.4(SEMA4G):​c.382A>G​(p.Thr128Ala) variant causes a missense 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 (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SEMA4G NM_017893.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.13

Genes affected

SEMA4G (HGNC:10735): (semaphorin 4G) Semaphorins are a large family of conserved secreted and membrane associated proteins which possess a semaphorin (Sema) domain and a PSI domain (found in plexins, semaphorins and integrins) in the N-terminal extracellular portion. Based on sequence and structural similarities, semaphorins are put into eight classes: invertebrates contain classes 1 and 2, viruses have class V, and vertebrates contain classes 3-7. Semaphorins serve as axon guidance ligands via multimeric receptor complexes, some (if not all) containing plexin proteins. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Feb 2011]

MRPL43 (HGNC:14517): (mitochondrial ribosomal protein L43) Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and help in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. They have an estimated 75% protein to rRNA composition compared to prokaryotic ribosomes, where this ratio is reversed. Another difference between mammalian mitoribosomes and prokaryotic ribosomes is that the latter contain a 5S rRNA. Among different species, the proteins comprising the mitoribosome differ greatly in sequence, and sometimes in biochemical properties, which prevents easy recognition by sequence homology. This gene encodes a 39S subunit protein. This gene and the gene for a semaphorin class 4 protein (SEMA4G) overlap at map location 10q24.31 and are transcribed in opposite directions. Sequence analysis identified multiple transcript variants encoding at least four different protein isoforms. [provided by RefSeq, Jul 2008]

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/exons	MANE	UniProt
SEMA4G	NM_017893.4	c.382A>G	p.Thr128Ala	missense_variant	5/15	ENST00000210633.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SEMA4G	ENST00000210633.4	c.382A>G	p.Thr128Ala	missense_variant	5/15	1	NM_017893.4	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 17, 2023

The c.382A>G (p.T128A) alteration is located in exon 4 (coding exon 4) of the SEMA4G gene. This alteration results from a A to G substitution at nucleotide position 382, causing the threonine (T) at amino acid position 128 to be replaced by an alanine (A). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.42
BayesDel_addAF	Benign	-0.053	T
BayesDel_noAF	Benign	-0.31
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Benign	0.14	.;T;T;.;.
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.37
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.93	D;T;D;D;D
M_CAP	Benign	0.057	D
MetaRNN	Uncertain	0.68	D;D;D;D;D
MetaSVM	Benign	-0.59	T
MutationAssessor	Pathogenic	3.1	.;.;M;M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.56	T
PROVEAN	Uncertain	-3.3	D;D;D;D;D
REVEL	Benign	0.24
Sift	Uncertain	0.0050	D;D;D;D;D
Sift4G	Benign	0.061	T;D;D;D;D
Polyphen		0.88, 0.21	.;.;P;.;B
Vest4		0.58, 0.53, 0.59
MutPred		0.73		Loss of stability (P = 0.0202);Loss of stability (P = 0.0202);Loss of stability (P = 0.0202);Loss of stability (P = 0.0202);Loss of stability (P = 0.0202);
MVP		0.76
MPC		0.34
ClinPred		0.97	D
GERP RS		4.2
Varity_R		0.81
gMVP		0.85

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: rs779061181; hg19: chr10-102737434;