4-83456130-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_016067.4(MRPS18C):c.53A>C(p.His18Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,613,406 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000015 (0 hom.)
• Consequence: MRPS18C NM_016067.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.770

Genes affected

MRPS18C (HGNC:16633): (mitochondrial ribosomal protein S18C) 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. Pseudogenes corresponding to this gene are found on chromosomes 8p, 12p, 15q, and 22q. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.103428155).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MRPS18C	NM_016067.4	c.53A>C	p.His18Pro	missense_variant	1/6	ENST00000295491.9
MRPS18C	NM_001297767.2	c.53A>C	p.His18Pro	missense_variant	1/5
MRPS18C	NM_001297769.2	c.53A>C	p.His18Pro	missense_variant	1/5
MRPS18C	NM_001297770.2	c.53A>C	p.His18Pro	missense_variant	1/4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MRPS18C	ENST00000295491.9	c.53A>C	p.His18Pro	missense_variant	1/6	1	NM_016067.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152118 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: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.0000151 AC: 22 AN: 1461288 Hom.: 0 Cov.: 32 AF XY: 0.0000138 AC XY: 10 AN XY: 726974

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000198

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152118 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74308

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

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

Jul 08, 2022

The c.53A>C (p.H18P) alteration is located in exon 1 (coding exon 1) of the MRPS18C gene. This alteration results from a A to C substitution at nucleotide position 53, causing the histidine (H) at amino acid position 18 to be replaced by a proline (P). 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	0.065
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.39
Cadd	Benign	0.69
Dann	Benign	0.53
DEOGEN2	Benign	0.020	T;.;T;.
Eigen	Benign	-1.6
Eigen_PC	Benign	-1.8
FATHMM_MKL	Benign	0.0088	N
LIST_S2	Benign	0.32	T;T;T;T
M_CAP	Benign	0.0016	T
MetaRNN	Benign	0.10	T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.7	L;.;.;.
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Benign	0.23	T
PROVEAN	Benign	-0.28	N;N;D;N
REVEL	Benign	0.16
Sift	Benign	0.27	T;T;T;T
Sift4G	Benign	0.28	T;T;T;T
Polyphen		0.0	B;.;.;.
Vest4		0.086
MutPred		0.41		Loss of sheet (P = 0.0228);Loss of sheet (P = 0.0228);Loss of sheet (P = 0.0228);.;
MVP		0.030
MPC		0.084
ClinPred		0.88	D
GERP RS		-9.6
Varity_R		0.073
gMVP		0.53

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: rs1446473381; hg19: chr4-84377283;