17-57840934-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_016070.4(MRPS23):c.412G>A(p.Ala138Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: MRPS23 NM_016070.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.477

Genes affected

MRPS23 (HGNC:14509): (mitochondrial ribosomal protein S23) 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 28S subunit protein. A pseudogene corresponding to this gene is found on chromosome 7p. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.052520543).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MRPS23	NM_016070.4	c.412G>A	p.Ala138Thr	missense_variant	4/5	ENST00000313608.13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MRPS23	ENST00000313608.13	c.412G>A	p.Ala138Thr	missense_variant	4/5	1	NM_016070.4	P1
MRPS23	ENST00000578444.1	c.412G>A	p.Ala138Thr	missense_variant	4/4	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 24, 2021

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The threonine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. This variant has not been reported in the literature in individuals affected with MRPS23-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces alanine with threonine at codon 138 of the MRPS23 protein (p.Ala138Thr). The alanine residue is weakly conserved and there is a small physicochemical difference between alanine and threonine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.071
BayesDel_addAF	Benign	-0.25	T
BayesDel_noAF	Benign	-0.60
Cadd	Benign	15
Dann	Uncertain	0.98
DEOGEN2	Benign	0.018	T;T
Eigen	Benign	-0.37
Eigen_PC	Benign	-0.25
FATHMM_MKL	Benign	0.76	D
LIST_S2	Benign	0.58	T;T
M_CAP	Benign	0.0055	T
MetaRNN	Benign	0.053	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.8	L;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-0.83	N;.
REVEL	Benign	0.14
Sift	Benign	0.30	T;.
Sift4G	Benign	0.44	T;T
Polyphen		0.011	B;.
Vest4		0.057
MutPred		0.33		Gain of relative solvent accessibility (P = 0.0215);Gain of relative solvent accessibility (P = 0.0215);
MVP		0.25
MPC		0.17
ClinPred		0.12	T
GERP RS		3.1
Varity_R		0.025
gMVP		0.45

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: chr17-55918295;