chrX-18672031-A-G

Variant names:

• chrX-18672031-A-G
• rs104894935
• NM_000330.4:c.38T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2 PP2 PP3_Strong

The NM_000330.4(RS1):​c.38T>C​(p.Leu13Pro) variant causes a missense change. 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 Uncertain significance (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L13I) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 22)
• Consequence: RS1 NM_000330.4 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:3 U:1 O:1
• Conservation: PhyloP100: 4.34
• Publications: 11 publications found

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]

RS1 Gene-Disease associations (from GenCC):

• retinoschisis

  Inheritance: XL Classification: DEFINITIVE Submitted by: G2P
• X-linked retinoschisis

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 110 curated pathogenic missense variants (we use a threshold of 10). The gene has 9 curated benign missense variants. Gene score misZ: 0.96911 (below the threshold of 3.09). Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to X-linked retinoschisis, retinoschisis.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.979

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RS1	NM_000330.4	c.38T>C	p.Leu13Pro	missense_variant	Exon 1 of 6	ENST00000379984.4	NP_000321.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RS1	ENST00000379984.4	c.38T>C	p.Leu13Pro	missense_variant	Exon 1 of 6	1	NM_000330.4	ENSP00000369320.3

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 22

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:3 Uncertain:1 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

not provided Pathogenic:2 Other:1

Oct 08, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine with proline at codon 13 of the RS1 protein (p.Leu13Pro). The leucine residue is highly conserved and there is a moderate physicochemical difference between leucine and proline. This variant is not present in population databases (ExAC no frequency). This variant has been observed in individual(s) with retinoschisis (PMID: 10533068, 30652005, 20809529, Invitae). ClinVar contains an entry for this variant (Variation ID: 9892). Experimental studies have shown that this variant affects RS1 protein function (PMID: 20809529). For these reasons, this variant has been classified as Pathogenic.

Retina International

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

Nov 02, 2023

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Published functional studies demonstrate a damaging effect on expression, consistent with a null allele (PMID: 20809529, 12746437); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 12746437, 36402656, 10533068, 20809529, 22183371, 22245536, 30652005)

Juvenile retinoschisis Pathogenic:1 Uncertain:1

Jan 01, 1999

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Sep 22, 2025

ClinGen X-linked Inherited Retinal Disease Variant Curation Expert Panel, ClinGen

Significance: Uncertain significance

Review Status: reviewed by expert panel

Collection Method: curation

NM_000330.4(RS1):c.38T>C (p.Leu13Pro) is a missense variant encoding the substitution of leucine with proline at amino acid 13. This variant is absent from hemizygous individuals in gnomAD v4.1.0 (PM2_Supporting). At least one proband harboring this variant exhibits a phenotype including appearance of schisis and reduced visual acuity before age 13 years, which together are specific for X-linked retinoschisis (PMID: 30652005, PP4). This variant has been reported in at least 1 proband meeting the PS4 requirement of a male diagnosed with X-linked retinoschisis, as well as a second apparently unrelated proband previously used for the PP4 code (PMID: 10533068, PMID: 20809529, PS4_Supporting). The computational predictor REVEL gives a score of 0.732, which is within the ClinGen X-linked IRD VCEP range between 0.772 to 0.644 and predicts a damaging effect on RS1 function (PP3). The computational splicing predictor SpliceAI gives a delta score of 0.00 for all predictive splice changes, which is below the ClinGen X-linked IRD VCEP threshold of >0.2 and does not predict that the variant disrupts RS1 splicing. COS-7 cells exogenously expressing the variant exhibit reduced levels of RS1 in the cell lysate relative to the wild-type control and loss of detectable RS1 secretion into the medium (PMID: 20809529, 12746437, PS3_Supporting). In summary, this variant is classified as a variant of uncertain significance for X-linked retinoschisis based on the ClinGen X-linked Inherited Retinal Disease Expert Panel Specifications to the ACMG/AMP Variant Interpretation Guidelines for RS1 Version 1.0.0: PM2_supporting, PS3_supporting, PP4, PS4_supporting, and PP3.

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.31
BayesDel_addAF	Pathogenic	0.64	D
BayesDel_noAF	Pathogenic	0.68
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.31	T
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Benign	0.48	T
M_CAP	Pathogenic	0.86	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.2	D
MutationAssessor	Benign	1.9	L
PhyloP100		4.3
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	-0.86	N
REVEL	Pathogenic	0.73
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0030	D
Vest4		0.92
ClinPred		0.83	D
GERP RS		5.7
PromoterAI		-0.0060	Neutral
Varity_R		0.62
gMVP		0.93
Mutation Taster		=19/81	disease causing (ClinVar)

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: rs104894935; hg19: chrX-18690151;