19-35842124-C-T

Variant names:

• chr19-35842124-C-T
• rs778951863
• NM_004646.4:c.2663G>A

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1 PM2 PP3_Moderate PP5_Very_Strong

The NM_004646.4(NPHS1):​c.2663G>A​(p.Arg888Lys) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: NPHS1 NM_004646.4 missense, splice_region
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3 U:1
• Conservation: PhyloP100: 5.87

Genes affected

NPHS1 (HGNC:7908): (NPHS1 adhesion molecule, nephrin) This gene encodes a member of the immunoglobulin family of cell adhesion molecules that functions in the glomerular filtration barrier in the kidney. The gene is primarily expressed in renal tissues, and the protein is a type-1 transmembrane protein found at the slit diaphragm of glomerular podocytes. The slit diaphragm is thought to function as an ultrafilter to exclude albumin and other plasma macromolecules in the formation of urine. Mutations in this gene result in Finnish-type congenital nephrosis 1, characterized by severe proteinuria and loss of the slit diaphragm and foot processes.[provided by RefSeq, Oct 2009]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PM1: In a disulfide_bond (size 57) in uniprot entity NPHN_HUMAN there are 9 pathogenic changes around while only 1 benign (90%) in NM_004646.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 19-35842124-C-T is Pathogenic according to our data. Variant chr19-35842124-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 554911.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NPHS1	NM_004646.4	c.2663G>A	p.Arg888Lys	missense_variant, splice_region_variant	Exon 19 of 29	ENST00000378910.10	NP_004637.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NPHS1	ENST00000378910.10	c.2663G>A	p.Arg888Lys	missense_variant, splice_region_variant	Exon 19 of 29	1	NM_004646.4	ENSP00000368190.4
NPHS1	ENST00000353632.6	c.2663G>A	p.Arg888Lys	missense_variant, splice_region_variant	Exon 19 of 28	5		ENSP00000343634.5

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Finnish congenital nephrotic syndrome Pathogenic:2 Uncertain:1

Nov 08, 2017

Counsyl

Significance: Uncertain significance

Review Status: flagged submission

Collection Method: clinical testing

- -

Mar 28, 2022

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 26, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: NPHS1 c.2663G>A (p.Arg888Lys) results in a conservative amino acid change located in the Immunoglobulin subtype 2 domain (IPR003598) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. In addition, this variant disrupts the last nucleotide of exon 19, and therefore may affect splicing. Several computational tools predict a significant impact on normal splicing: four predict the variant weakens a 5' donor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 229072 control chromosomes (gnomAD). c.2663G>A has been reported in the literature in both homozygous and compound heterozygous individuals affected with Nephrotic Syndrome (e.g., Wang_2017, Gungor_2021, Rong_2021, AlRiyami_2023). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 31456999, 31587616, 28160156, 34859019, 28204945, 37204080). ClinVar contains an entry for this variant (Variation ID: 554911). Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:1

Jan 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with lysine, which is basic and polar, at codon 888 of the NPHS1 protein (p.Arg888Lys). This variant also falls at the last nucleotide of exon 19, which is part of the consensus splice site for this exon. This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with nephrotic syndrome (PMID: 31456999, 31587616, 34859019). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 554911). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.53
BayesDel_addAF	Benign	-0.015	T
BayesDel_noAF	Benign	-0.26
CADD	Pathogenic	35
DANN	Uncertain	1.0
DEOGEN2	Benign	0.17	T;.
Eigen	Uncertain	0.65
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.74	T;T
M_CAP	Uncertain	0.18	D
MetaRNN	Pathogenic	0.76	D;D
MetaSVM	Benign	-0.35	T
MutationAssessor	Benign	0.74	N;N
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	-0.77	N;N
REVEL	Benign	0.28
Sift	Benign	0.39	T;T
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.68
MutPred		0.57		Gain of ubiquitination at R888 (P = 0.0066);Gain of ubiquitination at R888 (P = 0.0066);
MVP		0.91
MPC		0.52
ClinPred		0.98	D
GERP RS		4.8
Varity_R		0.25
gMVP		0.70

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.98
SpliceAI score (max)		0.60		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.43		Position offset: -38
DS_DL_spliceai		0.60		Position offset: 0

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

Publications

LitVar

Other links and lift over

dbSNP: rs778951863; hg19: chr19-36333026;