chr2-3575351-G-C

Position:

• chr2-3575351-G-C

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PVS1 PM2 PP3_Strong PP5

The NM_001011.4(RPS7):​c.-19+1G>C variant causes a splice donor change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: RPS7 NM_001011.4 splice_donor
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 2.18

Genes affected

RPS7 (HGNC:10440): (ribosomal protein S7) Ribosomes, the organelles that catalyze protein synthesis, consist of a small 40S subunit and a large 60S subunit. Together these subunits are composed of 4 RNA species and approximately 80 structurally distinct proteins. This gene encodes a ribosomal protein that is a component of the 40S subunit. The protein belongs to the S7E family of ribosomal proteins. It is located in the cytoplasm. As is typical for genes encoding ribosomal proteins, there are multiple processed pseudogenes of this gene dispersed through the genome. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 15 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
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 2-3575351-G-C is Pathogenic according to our data. Variant chr2-3575351-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 424204.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RPS7	NM_001011.4	c.-19+1G>C		splice_donor_variant		ENST00000645674.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RPS7	ENST00000645674.2	c.-19+1G>C		splice_donor_variant			NM_001011.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 0

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Diamond-Blackfan anemia 8 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Dec 21, 2023

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Likely pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with Diamond-Blackfan anaemia 8 (MIM#612563). (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0211 - Canonical splice site variant without proven consequence on splicing (no functional evidence available). However, this variant is located within the 5'-UTR and is predicted to result in the loss of the transcription start site. (SP) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0505 - Abnormal splicing is predicted by in silico tool and affected nucleotide is highly conserved. (SP) 0702 - Other variants comparable to the one identified in this case have strong previous evidence for pathogenicity. A substitution affecting the same nucleotide, c.-19+1G>A, was regarded as pathogenic in ClinVar. Another change, c.-19+1G>T, segregated in a Russian family with Diamond-Blackfan anaemia (DBA) and was shown to dramatically decrease mRNA and protein levels (PMID: 36057918). In addition, c.-19+2T>C was detected de novo in an individual with DBA (PMID: 25946618). (SP) 0809 - Previous evidence of pathogenicity for this variant is inconclusive. It has been regarded as VUS by GeneDx in an individual with DBA (ClinVar, personal communication) as well as in a Dutch DBA patient (PMID: 29114930). (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1102 - Strong phenotype match for this individual. (SP) 1206 - This variant has been shown to be paternally inherited but is suspected mosaic in the father. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Mar 13, 2017

The c.-19+1 G>C variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. Several in-silico splice prediction models predict that c.-19+1 G>C destroys the canonical splice donor site of exon 1; however, exon 1 is non-coding. In the absence of RNA/functional studies, the actual effect of this sequence change in this individual is unknown. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.49
CADD	Pathogenic	28
DANN	Benign	0.86
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.90
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.79		Position offset: 3
DS_DL_spliceai		1.0		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs1064796859; hg19: chr2-3622941;