3-139006253-G-A

Position:

• chr3-139006253-G-A

Variant summary

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

The NM_001134659.1(PRR23A):​c.16C>T​(p.Arg6Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000946 in 1,374,810 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000095 (0 hom.)
• Consequence: PRR23A NM_001134659.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.294

Genes affected

PRR23A (HGNC:37172): (proline rich 23A)

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=0.1401161).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PRR23A	NM_001134659.1	c.16C>T	p.Arg6Cys	missense_variant	1/1	ENST00000383163.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PRR23A	ENST00000383163.4	c.16C>T	p.Arg6Cys	missense_variant	1/1		NM_001134659.1	P1
MRPS22	ENST00000495075.5	c.-143+158G>A		intron_variant		1		P4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000946 AC: 13 AN: 1374810 Hom.: 0 Cov.: 35 AF XY: 0.00000295 AC XY: 2 AN XY: 678842

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000307

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: 0.0000102

Gnomad4 OTH exome AF: 0.0000175

GnomAD4 genome Cov.: 31

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

Mar 25, 2024

The c.16C>T (p.R6C) alteration is located in exon 1 (coding exon 1) of the PRR23A gene. This alteration results from a C to T substitution at nucleotide position 16, causing the arginine (R) at amino acid position 6 to be replaced by a cysteine (C). 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	0.13
BayesDel_addAF	Benign	-0.092	T
BayesDel_noAF	Benign	-0.37
CADD	Benign	20
DANN	Uncertain	0.98
DEOGEN2	Benign	0.11	T
Eigen	Benign	-0.55
Eigen_PC	Benign	-0.68
FATHMM_MKL	Benign	0.022	N
LIST_S2	Benign	0.70	T
M_CAP	Benign	0.011	T
MetaRNN	Benign	0.14	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Uncertain	2.1	M
MutationTaster	Benign	1.0	N;N
PrimateAI	Uncertain	0.67	T
PROVEAN	Pathogenic	-5.7	D
REVEL	Benign	0.032
Sift	Benign	0.088	T
Sift4G	Benign	0.096	T
Polyphen		0.55	P
Vest4		0.12
MutPred		0.46		Loss of MoRF binding (P = 8e-04);
MVP		0.092
MPC		0.78
ClinPred		0.56	D
GERP RS		1.7
Varity_R		0.12
gMVP		0.17

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: rs1166685278; hg19: chr3-138725095;