NM_000266.4:c.220C>T

Variant names:

• chrX-43949981-G-A
• rs727504031
• NM_000266.4:c.220C>T

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1 PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_000266.4(NDP):​c.220C>T​(p.Arg74Cys) variant causes a missense change involving the alteration of a 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R74S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 22)
• Consequence: NDP NM_000266.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 9.55
• Publications: 8 publications found

Genes affected

NDP (HGNC:7678): (norrin cystine knot growth factor NDP) This gene encodes a secreted protein with a cystein-knot motif that activates the Wnt/beta-catenin pathway. The protein forms disulfide-linked oligomers in the extracellular matrix. Mutations in this gene result in Norrie disease and X-linked exudative vitreoretinopathy. [provided by RefSeq, Feb 2009]

NDP-AS1 (HGNC:40395): (NDP antisense RNA 1)

ACMG classification

Our verdict: Pathogenic. The variant received 17 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_000266.4
• 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 32 curated pathogenic missense variants (we use a threshold of 10). The gene has 2 curated benign missense variants. Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to Norrie disease, exudative vitreoretinopathy 2, X-linked, exudative vitreoretinopathy, persistent hyperplastic primary vitreous.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.95
• PP5: Variant X-43949981-G-A is Pathogenic according to our data. Variant chrX-43949981-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 167326.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000266.4. 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
	NDP	NM_000266.4	MANE Select	c.220C>T	p.Arg74Cys	missense	Exon 3 of 3	NP_000257.1
	NDP-AS1	NR_046631.1		n.250G>A		non_coding_transcript_exon	Exon 1 of 6

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NDP	ENST00000642620.1	MANE Select	c.220C>T	p.Arg74Cys	missense	Exon 3 of 3	ENSP00000495972.1
	NDP	ENST00000647044.1		c.220C>T	p.Arg74Cys	missense	Exon 4 of 4	ENSP00000495811.1
	NDP	ENST00000868527.1		c.220C>T	p.Arg74Cys	missense	Exon 3 of 3	ENSP00000538586.1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 22

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
2	-	-	not provided (2)
1	-	-	Atrophia bulborum hereditaria (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.71
BayesDel_addAF	Pathogenic	0.67	D
BayesDel_noAF	Pathogenic	0.73
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.91	D
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.89	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Benign	0.90	L
PhyloP100		9.6
PrimateAI	Uncertain	0.74	T
PROVEAN	Uncertain	-3.1	D
REVEL	Pathogenic	0.87
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0090	D
Polyphen		1.0	D
Vest4		0.69
MutPred		0.73		Loss of solvent accessibility (P = 0.002)
MVP		1.0
MPC		1.3
ClinPred		0.99	D
GERP RS		6.0
Varity_R		0.92
gMVP		0.96
Mutation Taster		=12/88	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: rs727504031; hg19: chrX-43809227;