X-18644454-G-T

Position:

• chrX-18644454-G-T

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_000330.4(RS1):​c.498C>A​(p.Tyr166*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 22)
• Consequence: RS1 NM_000330.4 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 2.46

Genes affected

RS1 (HGNC:10457): (retinoschisin 1) This gene encodes an extracellular protein that plays a crucial role in the cellular organization of the retina. The encoded protein is assembled and secreted from photoreceptors and bipolar cells as a homo-oligomeric protein complex. Mutations in this gene are responsible for X-linked retinoschisis, a common, early-onset macular degeneration in males that results in a splitting of the inner layers of the retina and severe loss in vision. [provided by RefSeq, Oct 2008]

CDKL5 (HGNC:11411): (cyclin dependent kinase like 5) This gene is a member of Ser/Thr protein kinase family and encodes a phosphorylated protein with protein kinase activity. Mutations in this gene have been associated with X-linked infantile spasm syndrome (ISSX), also known as X-linked West syndrome, and Rett syndrome (RTT). Alternate transcriptional splice variants have been characterized. [provided by RefSeq, Jul 2008]

RS1 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 13 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-18644454-G-T is Pathogenic according to our data. Variant chrX-18644454-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 370754.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RS1	NM_000330.4	c.498C>A	p.Tyr166*	stop_gained	5/6	ENST00000379984.4	NP_000321.1
RS1	XM_047442337.1	c.402C>A	p.Tyr134*	stop_gained	3/4		XP_047298293.1
CDKL5	NM_001037343.2	c.2714-1553G>T		intron_variant			NP_001032420.1
CDKL5	NM_003159.3	c.2714-1553G>T		intron_variant			NP_003150.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RS1	ENST00000379984.4	c.498C>A	p.Tyr166*	stop_gained	5/6	1	NM_000330.4	ENSP00000369320.3
CDKL5	ENST00000379989.6	c.2714-1553G>T		intron_variant		1		ENSP00000369325.3
CDKL5	ENST00000379996.7	c.2714-1553G>T		intron_variant		1		ENSP00000369332.3
RS1	ENST00000476595.1	n.989C>A		non_coding_transcript_exon_variant	4/5	1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 22

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Juvenile retinoschisis Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Counsyl

Apr 06, 2016

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 28, 2020

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the C-terminus of the RS1 protein. Other variant(s) that disrupt this region (p.Trp206*) have been determined to be pathogenic (PMID: 17515881, 9618178, Invitae). This suggests that variants that disrupt this region of the protein are likely to be causative of disease. This variant has not been reported in the literature in individuals with RS1-related conditions. ClinVar contains an entry for this variant (Variation ID: 370754). This variant is not present in population databases (ExAC no frequency). This sequence change results in a premature translational stop signal in the RS1 gene (p.Tyr166*). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 59 amino acids of the RS1 protein. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	34
DANN	Uncertain	0.99
FATHMM_MKL	Uncertain	0.86	D
Vest4		0.99
GERP RS		-1.7

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: rs1057516744; hg19: chrX-18662574;