6-43671871-G-A

Position:

• chr6-43671871-G-A

Variant summary

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

The NM_018135.4(MRPS18A):​c.482C>T​(p.Pro161Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,312 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MRPS18A NM_018135.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.87

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]

RSPH9 (HGNC:21057): (radial spoke head component 9) This gene encodes a protein thought to be a component of the radial spoke head in motile cilia and flagella. Mutations in this gene are associated with primary ciliary dyskinesia 12. Alternative splicing results in multiple transcript variants.[provided by RefSeq, Jul 2010]

POLR1C (HGNC:20194): (RNA polymerase I and III subunit C) The protein encoded by this gene is a subunit of both RNA polymerase I and RNA polymerase III complexes. The encoded protein is part of the Pol core element. Mutations in this gene have been associated with Treacher Collins syndrome (TCS) and hypomyelinating leukodystrophy 11. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2016]

RSPH9 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MRPS18A	NM_018135.4	c.482C>T	p.Pro161Leu	missense_variant	6/6	ENST00000372133.8	NP_060605.1
RSPH9	NM_152732.5	c.*922G>A		3_prime_UTR_variant	5/5	ENST00000372163.5	NP_689945.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MRPS18A	ENST00000372133.8	c.482C>T	p.Pro161Leu	missense_variant	6/6	1	NM_018135.4	ENSP00000361206.3
RSPH9	ENST00000372163.5	c.*922G>A		3_prime_UTR_variant	5/5	1	NM_152732.5	ENSP00000361236.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461312 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726938

Gnomad4 AFR exome AF: 0.0000299

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000370 Hom.: 0

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

Dec 14, 2023

The c.482C>T (p.P161L) alteration is located in exon 6 (coding exon 6) of the MRPS18A gene. This alteration results from a C to T substitution at nucleotide position 482, causing the proline (P) at amino acid position 161 to be replaced by a leucine (L). 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	Pathogenic	0.63
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.19	T;T
Eigen	Pathogenic	0.77
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.88	D;D
M_CAP	Uncertain	0.11	D
MetaRNN	Uncertain	0.71	D;D
MetaSVM	Benign	-0.29	T
MutationAssessor	Uncertain	2.7	M;.
PrimateAI	Uncertain	0.61	T
PROVEAN	Uncertain	-3.0	D;D
REVEL	Uncertain	0.38
Sift	Uncertain	0.0030	D;D
Sift4G	Pathogenic	0.0	D;.
Polyphen		0.82	P;.
Vest4		0.71
MVP		0.48
MPC		0.58
ClinPred		0.99	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.73
gMVP		0.82

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: rs1043011545; hg19: chr6-43639608; COSMIC: COSV64522310;