X-18642022-GC-CT

Variant names:

• chrX-18642022-GC-CT
• NM_000330.4:c.656_657delGCinsAG

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000330.4(RS1):​c.656_657delGCinsAG​(p.Cys219*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 23)
• Consequence: RS1 NM_000330.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.57

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]

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-18642022-GC-CT is Pathogenic according to our data. Variant chrX-18642022-GC-CT is described in ClinVar as [Pathogenic]. Clinvar id is 2123578.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RS1	NM_000330.4	c.656_657delGCinsAG	p.Cys219*	stop_gained		ENST00000379984.4	NP_000321.1
RS1	XM_047442337.1	c.560_561delGCinsAG	p.Cys187*	stop_gained			XP_047298293.1
CDKL5	NM_001037343.2	c.2714-3985_2714-3984delGCinsCT		intron_variant	Intron 19 of 21		NP_001032420.1
CDKL5	NM_003159.3	c.2714-3985_2714-3984delGCinsCT		intron_variant	Intron 18 of 20		NP_003150.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RS1	ENST00000379984.4	c.656_657delGCinsAG	p.Cys219*	stop_gained		1	NM_000330.4	ENSP00000369320.3
CDKL5	ENST00000379989.6	c.2714-3985_2714-3984delGCinsCT		intron_variant	Intron 19 of 21	1		ENSP00000369325.3
CDKL5	ENST00000379996.7	c.2714-3985_2714-3984delGCinsCT		intron_variant	Intron 18 of 20	1		ENSP00000369332.3
RS1	ENST00000476595.1	n.1147_1148delGCinsAG		non_coding_transcript_exon_variant	Exon 5 of 5	1

Frequencies

GnomAD3 genomes Cov.: 23

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Apr 09, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the RS1 protein in which other variant(s) (p.Cys223Tyr) have been determined to be pathogenic (PMID: 20061330, 22245991; Invitae). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. This variant has not been reported in the literature in individuals affected with RS1-related conditions. Information on the frequency of this variant in the gnomAD database is not available, as this variant may be reported differently in the database. This sequence change creates a premature translational stop signal (p.Cys219*) in the RS1 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 6 amino acid(s) of the RS1 protein. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chrX-18660142;