chr20-968119-GC-G

Variant names:

• chr20-968119-GC-G
• rs768138495
• NM_001029871.4:c.98delG

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_001029871.4(RSPO4):​c.98delG​(p.Gly33AlafsTer193) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,730 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: RSPO4 NM_001029871.4 frameshift
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.44
• Publications: 0 publications found

Genes affected

RSPO4 (HGNC:16175): (R-spondin 4) This gene encodes a member of the R-spondin family of proteins that share a common domain organization consisting of a signal peptide, cysteine-rich/furin-like domain, thrombospondin domain and a C-terminal basic region. The encoded protein may be involved in activation of Wnt/beta-catenin signaling pathways. Mutations in this gene are associated with anonychia congenital. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Sep 2009]

RSPO4 Gene-Disease associations (from GenCC):

• nonsyndromic congenital nail disorder 4

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, G2P, PanelApp Australia, Orphanet, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 9 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001029871.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RSPO4	NM_001029871.4	MANE Select	c.98delG	p.Gly33AlafsTer193	frameshift	Exon 2 of 5	NP_001025042.2	Q2I0M5-1
	RSPO4	NM_001040007.3		c.98delG	p.Gly33AlafsTer131	frameshift	Exon 2 of 4	NP_001035096.1	Q2I0M5-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RSPO4	ENST00000217260.9	TSL:1 MANE Select	c.98delG	p.Gly33AlafsTer193	frameshift	Exon 2 of 5	ENSP00000217260.4	Q2I0M5-1
	RSPO4	ENST00000400634.2	TSL:1	c.98delG	p.Gly33AlafsTer131	frameshift	Exon 2 of 4	ENSP00000383475.2	Q2I0M5-2
	RSPO4	ENST00000922623.1		c.98delG	p.Gly33AlafsTer84	frameshift	Exon 2 of 3	ENSP00000592682.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461730 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727168

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: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53308

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5752

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111986

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.4

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

Other links and lift over

dbSNP: rs768138495; hg19: chr20-948762; COSMIC: COSV99448852;