9-123356318-C-T

Position:

• chr9-123356318-C-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_173689.7(CRB2):​c.58C>T​(p.Leu20=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000287 in 1,395,520 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: 31)
  • Exomes 𝑓: 0.0000029 (0 hom.)
• Consequence: CRB2 NM_173689.7 synonymous
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.376

Genes affected

CRB2 (HGNC:18688): (crumbs cell polarity complex component 2) This gene encodes a member of a family of proteins that are components of the Crumbs cell polarity complex. In mammals, members of this family are thought to play a role in many cellular processes in early embryonic development. A similar protein in Drosophila determines apicobasal polarity in embryonic epithelial cells. Mutations in this gene are associated with focal segmental glomerulosclerosis 9, and with ventriculomegaly with cystic kidney disease. [provided by RefSeq, Aug 2016]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.52).
• BP7: Synonymous conserved (PhyloP=0.376 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CRB2	NM_173689.7	c.58C>T	p.Leu20=	synonymous_variant	1/13	ENST00000373631.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CRB2	ENST00000373631.8	c.58C>T	p.Leu20=	synonymous_variant	1/13	1	NM_173689.7	P1
CRB2	ENST00000359999.7	c.58C>T	p.Leu20=	synonymous_variant	1/10	2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000287 AC: 4 AN: 1395520 Hom.: 0 Cov.: 32 AF XY: 0.00000145 AC XY: 1 AN XY: 688370

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: 0.00000278

Gnomad4 OTH exome AF: 0.0000173

GnomAD4 genome Cov.: 31

Bravo AF: 0.00000378

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

GeneDx

Jun 06, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this variant does not alter splicing; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.52
CADD	Benign	6.9
DANN	Benign	0.74

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: rs992216922; hg19: chr9-126118597;