rs371077650

chr20-428988-A-G

Variant summary

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

The NM_031229.4(RBCK1):c.1346A>G(p.Gln449Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000931 in 1,611,516 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: RBCK1 NM_031229.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.708

Genes affected

RBCK1 (HGNC:15864): (RANBP2-type and C3HC4-type zinc finger containing 1) Enables several functions, including identical protein binding activity; protein sequestering activity; and ubiquitin binding activity. Involved in several processes, including T cell receptor signaling pathway; cellular protein metabolic process; and regulation of DNA-binding transcription factor activity. Part of LUBAC complex. Implicated in glycogen storage disease. [provided by Alliance of Genome Resources, Apr 2022]

TBC1D20 (HGNC:16133): (TBC1 domain family member 20) This gene encodes a protein that belongs to a family of GTPase activator proteins of Rab-like small GTPases. The encoded protein and its cognate GTPase, Rab1, bind the nonstructural protein 5A (NS5A) of the hepatitis C virus (HCV) to mediate viral replication. Depletion of this protein inhibits replication of the virus and HCV infection. Mutations in this gene are associated with Warburg micro syndrome 4. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Mar 2014]

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=0.070827514).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RBCK1	NM_031229.4	c.1346A>G	p.Gln449Arg	missense_variant	11/12	ENST00000356286.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RBCK1	ENST00000356286.10	c.1346A>G	p.Gln449Arg	missense_variant	11/12	1	NM_031229.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152148 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000724

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: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000243 AC: 6 AN: 246990 Hom.: 0 AF XY: 0.0000149 AC XY: 2 AN XY: 134432

Gnomad AFR exome AF: 0.000188

Gnomad AMR exome AF: 0.00

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: 0.0000270

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000822 AC: 12 AN: 1459368 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 726096

Gnomad4 AFR exome AF: 0.000149

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: 0.00000360

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152148 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74318

Gnomad4 AFR AF: 0.0000724

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: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000658 Hom.: 0

Bravo AF: 0.0000642

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.0000412 AC: 5

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Polyglucosan body myopathy type 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 09, 2022

This sequence change replaces glutamine, which is neutral and polar, with arginine, which is basic and polar, at codon 449 of the RBCK1 protein (p.Gln449Arg). This variant is present in population databases (rs371077650, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with RBCK1-related conditions. ClinVar contains an entry for this variant (Variation ID: 575892). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The arginine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.066
BayesDel_addAF	Benign	-0.31	T
BayesDel_noAF	Benign	-0.40
Cadd	Benign	18
Dann	Uncertain	0.99
DEOGEN2	Benign	0.15	T;.;.;.
Eigen	Benign	-0.55
Eigen_PC	Benign	-0.37
FATHMM_MKL	Benign	0.27	N
LIST_S2	Benign	0.80	T;T;T;.
M_CAP	Benign	0.0058	T
MetaRNN	Benign	0.071	T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	-0.69	N;.;.;.
MutationTaster	Benign	0.98	N;N;N
PrimateAI	Benign	0.33	T
PROVEAN	Benign	-0.64	N;.;N;N
REVEL	Benign	0.038
Sift	Benign	0.52	T;.;T;T
Sift4G	Benign	0.45	T;.;T;T
Polyphen		0.0010	B;B;B;B
Vest4		0.23
MVP		0.53
MPC		0.45
ClinPred		0.055	T
GERP RS		3.9
Varity_R		0.062
gMVP		0.30

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs371077650; hg19: chr20-409632;