2-27781660-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_022128.3(RBKS):c.924G>C(p.Gln308His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000409 in 1,613,780 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000042 (0 hom.)
• Consequence: RBKS NM_022128.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.914

Genes affected

RBKS (HGNC:30325): (ribokinase) This gene encodes a member of the carbohydrate kinase PfkB family. The encoded protein phosphorylates ribose to form ribose-5-phosphate in the presence of ATP and magnesium as a first step in ribose metabolism. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2013]

MRPL33 (HGNC:14487): (mitochondrial ribosomal protein L33) 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 39S subunit protein. Alternatively spliced transcript variants encoding different isoforms have been described. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.883

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RBKS	NM_022128.3	c.924G>C	p.Gln308His	missense_variant	8/8	ENST00000302188.8
RBKS	NM_001287580.2	c.723G>C	p.Gln241His	missense_variant	9/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RBKS	ENST00000302188.8	c.924G>C	p.Gln308His	missense_variant	8/8	1	NM_022128.3	P1
RBKS	ENST00000449378.1	c.*1851G>C		3_prime_UTR_variant, NMD_transcript_variant	9/9	1
MRPL33	ENST00000448427.1	c.42-912C>G		intron_variant, NMD_transcript_variant		4

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152092 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

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

GnomAD3 exomes AF: 0.0000518 AC: 13 AN: 251188 Hom.: 0 AF XY: 0.0000442 AC XY: 6 AN XY: 135770

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000174

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000616

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000424 AC: 62 AN: 1461688 Hom.: 0 Cov.: 30 AF XY: 0.0000275 AC XY: 20 AN XY: 727160

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000895

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: 0.0000522

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152092 Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3 AN XY: 74276

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000131

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: 0.0000453

ExAC AF: 0.0000576 AC: 7

EpiCase AF: 0.0000545

EpiControl AF: 0.000119

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 29, 2021

The c.924G>C (p.Q308H) alteration is located in exon 8 (coding exon 8) of the RBKS gene. This alteration results from a G to C substitution at nucleotide position 924, causing the glutamine (Q) at amino acid position 308 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	Pathogenic	0.98
BayesDel_addAF	Uncertain	0.098	D
BayesDel_noAF	Pathogenic	0.17
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.68	D
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.88	D
M_CAP	Uncertain	0.20	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Uncertain	0.58	D
MutationAssessor	Pathogenic	3.3	M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.54	T
PROVEAN	Uncertain	-4.0	D
REVEL	Pathogenic	0.74
Sift	Benign	0.15	T
Sift4G	Benign	0.076	T
Polyphen		1.0	D
Vest4		0.84
MutPred		0.68		Loss of solvent accessibility (P = 0.0022);
MVP		0.93
MPC		0.26
ClinPred		0.71	D
GERP RS		5.8
Varity_R		0.73
gMVP		0.86

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: rs888816409; hg19: chr2-28004527; COSMIC: COSV99941368; COSMIC: COSV99941368;