3-139020036-C-G

Variant summary

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

The NM_001013650.2(PRR23B):c.626G>C(p.Arg209Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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: not found (cov: 32)
• Consequence: PRR23B NM_001013650.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0390

Genes affected

PRR23B (HGNC:33764): (proline rich 23B)

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]

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=0.15022469).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PRR23B	NM_001013650.2	c.626G>C	p.Arg209Pro	missense_variant	1/1	ENST00000329447.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PRR23B	ENST00000329447.5	c.626G>C	p.Arg209Pro	missense_variant	1/1		NM_001013650.2	P1
MRPS22	ENST00000495075.5	c.-143+13941C>G		intron_variant		1		P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Bravo AF: 0.0000151

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

Oct 20, 2021

The c.626G>C (p.R209P) alteration is located in exon 1 (coding exon 1) of the PRR23B gene. This alteration results from a G to C substitution at nucleotide position 626, causing the arginine (R) at amino acid position 209 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	0.12
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.44
Cadd	Benign	15
Dann	Benign	0.94
DEOGEN2	Benign	0.023	T
Eigen	Benign	-0.49
Eigen_PC	Benign	-0.75
FATHMM_MKL	Benign	0.013	N
LIST_S2	Benign	0.32	T
M_CAP	Benign	0.0032	T
MetaRNN	Benign	0.15	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.8	L
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.27	T
PROVEAN	Benign	-1.7	N
REVEL	Benign	0.064
Sift	Benign	0.20	T
Sift4G	Benign	0.20	T
Polyphen		0.97	D
Vest4		0.17
MutPred		0.45		Gain of glycosylation at R209 (P = 0.013);
MVP		0.030
MPC		1.6
ClinPred		0.56	D
GERP RS		-0.35
Varity_R		0.25
gMVP		0.12

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1205571748; hg19: chr3-138738878;