chr18-22982394-G-A

Variant names:

• chr18-22982394-G-A
• rs587780432
• NM_002894.3:c.604+1G>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_002894.3(RBBP8):​c.604+1G>A variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.000000684 in 1,461,534 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: RBBP8 NM_002894.3 splice_donor, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.88
• Publications: 0 publications found

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]

RBBP8 Gene-Disease associations (from GenCC):

• Jawad syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet
• Seckel syndrome 2

  Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics
• Seckel syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002894.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RBBP8	NM_002894.3	MANE Select	c.604+1G>A		splice_donor intron	N/A	NP_002885.1
	RBBP8	NM_203291.2		c.604+1G>A		splice_donor intron	N/A	NP_976036.1
	RBBP8	NM_203292.2		c.604+1G>A		splice_donor intron	N/A	NP_976037.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RBBP8	ENST00000327155.10	TSL:1 MANE Select	c.604+1G>A		splice_donor intron	N/A	ENSP00000323050.5
	RBBP8	ENST00000360790.9	TSL:1	c.604+1G>A		splice_donor intron	N/A	ENSP00000354024.5
	RBBP8	ENST00000399722.6	TSL:1	c.604+1G>A		splice_donor intron	N/A	ENSP00000382628.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461534 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727086

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39682

South Asian (SAS) AF: 0.00 AC: 0 AN: 86234

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53210

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111918

Other (OTH) AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	-0.080
CADD	Pathogenic	32
DANN	Benign	0.96
Eigen	Pathogenic	0.74
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Uncertain	0.91	D
PhyloP100		5.9
GERP RS		4.3
Mutation Taster		=3/97	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.92
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DL_spliceai		1.0		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs587780432; hg19: chr18-20562357;