6-43678549-C-T

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_ModerateBS2

The NM_018135.4(MRPS18A):c.221G>A(p.Arg74His) variant causes a missense change. The variant allele was found at a frequency of 0.0000725 in 1,613,680 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts 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. R74C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000073 ( 2 hom. )

Consequence

MRPS18A
NM_018135.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.38

Variant links:

Genes affected

MRPS18A (HGNC:14515): (mitochondrial ribosomal protein S18A) 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 belongs to the ribosomal protein S18P family. The encoded protein is one of three that has significant sequence similarity to bacterial S18 proteins. The primary sequences of the three human mitochondrial S18 proteins are no more closely related to each other than they are to the prokaryotic S18 proteins. A pseudogene corresponding to this gene is found on chromosome 3p. Alternative splicing results in multiple transcript variants.[provided by RefSeq, Jul 2010]

MRPS18A links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.26337525).

BS2

High Homozygotes in GnomAdExome4 at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MRPS18A	NM_018135.4 link	c.221G>A	p.Arg74His	missense_variant	Exon 3 of 6	ENST00000372133.8	NP_060605.1	Q9NVS2-1
MRPS18A	NM_001193343.2 link	c.221G>A	p.Arg74His	missense_variant	Exon 3 of 5		NP_001180272.1	Q9NVS2-3
MRPS18A	XM_006715134.4 link	c.221G>A	p.Arg74His	missense_variant	Exon 3 of 5		XP_006715197.1	Q9NVS2-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
MRPS18A	ENST00000372133.8 link	c.221G>A	p.Arg74His	missense_variant	Exon 3 of 6	1	NM_018135.4	ENSP00000361206.3	Q9NVS2-1
MRPS18A	ENST00000427312.1 link	c.221G>A	p.Arg74His	missense_variant	Exon 3 of 5	1		ENSP00000398679.1	Q5QPA5
MRPS18A	ENST00000372116.5 link	c.221G>A	p.Arg74His	missense_variant	Exon 3 of 5	2		ENSP00000361188.1	Q9NVS2-3

Frequencies

GnomAD3 genomes

AF:

0.0000657

AC:

AN:

152166

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00104

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000103

AC:

AN:

251476

Hom.:

AF XY:

0.000125

AC XY:

AN XY:

135914

show subpopulations

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 SAS exome

AF:

0.000621

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000527

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000732

AC:

107

AN:

1461514

Hom.:

Cov.:

AF XY:

0.0000839

AC XY:

AN XY:

727072

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.000603

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000468

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000657

AC:

AN:

152166

Hom.:

Cov.:

AF XY:

0.0000942

AC XY:

AN XY:

74332

show subpopulations

Gnomad4 AFR

AF:

0.0000724

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00104

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000900

Hom.:

Bravo

AF:

0.0000340

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000988

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Dec 20, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.221G>A (p.R74H) alteration is located in exon 3 (coding exon 3) of the MRPS18A gene. This alteration results from a G to A substitution at nucleotide position 221, causing the arginine (R) at amino acid position 74 to be replaced by a histidine (H). 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

Benign

0.17

BayesDel_addAF

Uncertain

0.12

BayesDel_noAF

Pathogenic

0.28

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.36

T;.;T

Eigen

Pathogenic

0.84

Eigen_PC

Pathogenic

0.81

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.81

T;T;T

M_CAP

Benign

0.066

MetaRNN

Benign

0.26

T;T;T

MetaSVM

Uncertain

-0.10

MutationAssessor

Uncertain

2.6

M;M;.

PrimateAI

Uncertain

0.67

PROVEAN

Benign

-2.3

N;N;D

REVEL

Benign

0.23

Sift

Uncertain

0.0090

D;D;D

Sift4G

Uncertain

0.013

D;T;.

Polyphen

1.0

D;.;D

Vest4

0.83

MVP

0.66

MPC

0.62

ClinPred

0.56

GERP RS

5.7

Varity_R

0.41

gMVP

0.73

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over