NM_020191.4:c.283A>G

Variant names:

• chr3-139346988-A-G
• rs73866065
• NM_020191.4:c.283A>G

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_020191.4(MRPS22):​c.283A>G​(p.Ile95Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000322 in 1,614,084 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I95L) has been classified as Benign.

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000032 (0 hom.)
• Consequence: MRPS22 NM_020191.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.359
• Publications: 6 publications found

Genes affected

MRPS22 (HGNC:14508): (mitochondrial ribosomal protein S22) 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 that does not seem to have a counterpart in prokaryotic and fungal-mitochondrial ribosomes. This gene lies telomeric of and is transcribed in the opposite direction from the forkhead box L2 gene. A pseudogene corresponding to this gene is found on chromosome Xq. [provided by RefSeq, Jul 2008]

MRPS22 Gene-Disease associations (from GenCC):

• mitochondrial disease

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• hypotonia with lactic acidemia and hyperammonemia

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, G2P
• 46 XX gonadal dysgenesis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• ovarian dysgenesis 7

  Inheritance: AR Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.01939243).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020191.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MRPS22	NM_020191.4	MANE Select	c.283A>G	p.Ile95Val	missense	Exon 2 of 8	NP_064576.1
	MRPS22	NM_001363893.1		c.280A>G	p.Ile94Val	missense	Exon 2 of 8	NP_001350822.1
	MRPS22	NM_001363857.1		c.160A>G	p.Ile54Val	missense	Exon 2 of 8	NP_001350786.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MRPS22	ENST00000680020.1	MANE Select	c.283A>G	p.Ile95Val	missense	Exon 2 of 8	ENSP00000505414.1
	MRPS22	ENST00000495075.5	TSL:1	c.283A>G	p.Ile95Val	missense	Exon 4 of 10	ENSP00000418008.1
	MRPS22	ENST00000310776.9	TSL:1	c.280A>G	p.Ile94Val	missense	Exon 2 of 8	ENSP00000310785.5

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152204 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000828

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000239 AC: 6 AN: 251450 AF XY: 0.0000368

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000322 AC: 47 AN: 1461880 Hom.: 0 Cov.: 31 AF XY: 0.0000385 AC XY: 28 AN XY: 727240

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

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.0000504 AC: 2 AN: 39696

South Asian (SAS) AF: 0.000348 AC: 30 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 0.0000126 AC: 14 AN: 1112004

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome AF: 0.0000329 AC: 5 AN: 152204 Hom.: 0 Cov.: 32 AF XY: 0.0000538 AC XY: 4 AN XY: 74360

African (AFR) AF: 0.00 AC: 0 AN: 41438

American (AMR) AF: 0.00 AC: 0 AN: 15288

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5196

South Asian (SAS) AF: 0.000828 AC: 4 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10630

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68030

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 60

Bravo AF: 0.0000113

ExAC AF: 0.0000247 AC: 3

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

May 27, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 95 of the MRPS22 protein (p.Ile95Val). This variant is present in population databases (rs73866065, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with MRPS22-related conditions. 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 valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.067
BayesDel_addAF	Benign	-0.32	T
BayesDel_noAF	Benign	-0.43
CADD	Benign	0.0050
DANN	Benign	0.60
DEOGEN2	Benign	0.16	T
Eigen	Benign	-1.8
Eigen_PC	Benign	-1.9
FATHMM_MKL	Benign	0.048	N
LIST_S2	Benign	0.64	T
M_CAP	Benign	0.0086	T
MetaRNN	Benign	0.019	T
MetaSVM	Benign	-0.93	T
MutationAssessor	Benign	0.55	N
PhyloP100		-0.36
PrimateAI	Benign	0.25	T
PROVEAN	Benign	0.35	N
REVEL	Benign	0.19
Sift	Benign	0.44	T
Sift4G	Benign	0.33	T
Polyphen		0.0010	B
Vest4		0.11
MutPred		0.25		Gain of glycosylation at T90 (P = 0.0202)
MVP		0.38
MPC		0.24
ClinPred		0.027	T
GERP RS		-11
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.015
gMVP		0.17
Mutation Taster		=98/2	polymorphism

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

Other links and lift over

dbSNP: rs73866065; hg19: chr3-139065830;