18-22936925-C-T

Position:

• chr18-22936925-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_002894.3(RBBP8):​c.74C>T​(p.Thr25Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,808 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: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: RBBP8 NM_002894.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.57

Genes affected

RBBP8 (HGNC:9891): (RB binding protein 8, endonuclease) The protein encoded by this gene is a ubiquitously expressed nuclear protein. It is found among several proteins that bind directly to retinoblastoma protein, which regulates cell proliferation. This protein complexes with transcriptional co-repressor CTBP. It is also associated with BRCA1 and is thought to modulate the functions of BRCA1 in transcriptional regulation, DNA repair, and/or cell cycle checkpoint control. It is suggested that this gene may itself be a tumor suppressor acting in the same pathway as BRCA1. Three transcript variants encoding two different isoforms have been found for this gene. More transcript variants exist, but their full-length natures have not been determined. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.27470782).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RBBP8	NM_002894.3	c.74C>T	p.Thr25Ile	missense_variant	2/19	ENST00000327155.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RBBP8	ENST00000327155.10	c.74C>T	p.Thr25Ile	missense_variant	2/19	1	NM_002894.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251364 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135868

Gnomad AFR exome AF: 0.00

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: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461808 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 727204

Gnomad4 AFR exome AF: 0.00

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: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000468 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 05, 2021

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with RBBP8-related conditions. This variant is present in population databases (rs751695183, gnomAD 0.0009%). This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 25 of the RBBP8 protein (p.Thr25Ile). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.26
BayesDel_addAF	Benign	-0.097	T
BayesDel_noAF	Benign	-0.38
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.092	T;.;T;.;D;D;.;T;.
Eigen	Benign	-0.091
Eigen_PC	Benign	-0.020
FATHMM_MKL	Benign	0.43	N
LIST_S2	Uncertain	0.91	D;D;D;D;.;D;D;D;D
M_CAP	Benign	0.031	D
MetaRNN	Benign	0.27	T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	0.97	N;N;N;N
PrimateAI	Uncertain	0.49	T
Sift4G	Uncertain	0.0080	D;D;T;D;D;D;D;D;D
Polyphen		0.93	.;.;.;.;P;P;.;.;.
Vest4		0.32, 0.32, 0.39
MutPred		0.58		Loss of disorder (P = 0.0274);Loss of disorder (P = 0.0274);Loss of disorder (P = 0.0274);Loss of disorder (P = 0.0274);Loss of disorder (P = 0.0274);Loss of disorder (P = 0.0274);Loss of disorder (P = 0.0274);Loss of disorder (P = 0.0274);Loss of disorder (P = 0.0274);
MVP		0.32
MPC		0.18
ClinPred		0.87	D
GERP RS		3.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.30
gMVP		0.059

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: rs751695183; hg19: chr18-20516888;