NM_020191.4:c.605G>T

Variant names:

• chr3-139350279-G-T
• rs753345594
• NM_020191.4:c.605G>T

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_020191.4(MRPS22):​c.605G>T​(p.Arg202Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R202H) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MRPS22 NM_020191.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.13
• Publications: 10 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_pathogenic. The variant received 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-139350279-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 441255.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MRPS22	NM_020191.4	c.605G>T	p.Arg202Leu	missense_variant	Exon 4 of 8	ENST00000680020.1	NP_064576.1
MRPS22	NM_001363893.1	c.602G>T	p.Arg201Leu	missense_variant	Exon 4 of 8		NP_001350822.1
MRPS22	NM_001363857.1	c.482G>T	p.Arg161Leu	missense_variant	Exon 4 of 8		NP_001350786.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MRPS22	ENST00000680020.1	c.605G>T	p.Arg202Leu	missense_variant	Exon 4 of 8		NM_020191.4	ENSP00000505414.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251424 AF XY: 0.00

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 Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.88
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.88	D;D;D;.
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	.;D;D;D
M_CAP	Pathogenic	0.34	D
MetaRNN	Pathogenic	0.99	D;D;D;D
MetaSVM	Pathogenic	0.88	D
MutationAssessor	Pathogenic	3.2	M;M;.;.
PhyloP100		9.1
PrimateAI	Benign	0.47	T
PROVEAN	Pathogenic	-6.1	D;D;D;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0020	D;D;D;D
Sift4G	Uncertain	0.0030	D;D;D;D
Polyphen		1.0	D;D;D;D
Vest4		0.96
MutPred		0.96		Loss of glycosylation at P198 (P = 0.0489);Loss of glycosylation at P198 (P = 0.0489);.;.;
MVP		0.98
MPC		1.1
ClinPred		0.99	D
GERP RS		4.6
Varity_R		0.71
gMVP		0.89
Mutation Taster		=12/88	disease causing

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: rs753345594; hg19: chr3-139069121;