Genetic Variant NM_004646.4:c.3312-1G>C (chr19-35831372-C-G) – ACMG Classification: Pathogenic (18 pts)

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_004646.4(NPHS1):c.3312-1G>C variant causes a splice acceptor, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,842 control chromosomes in the GnomAD database, with no homozygous occurrence. 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)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

NPHS1
NM_004646.4 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 3.33

Variant links:

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]

NPHS1 links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 19-35831372-C-G is Pathogenic according to our data. Variant chr19-35831372-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2145832.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 link	c.3312-1G>C		splice_acceptor_variant, intron_variant	Intron 25 of 28	ENST00000378910.10	NP_004637.1	O60500-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NPHS1	ENST00000378910.10 link	c.3312-1G>C		splice_acceptor_variant, intron_variant	Intron 25 of 28	1	NM_004646.4	ENSP00000368190.4		O60500-1
NPHS1	ENST00000353632.6 link	c.3192-1G>C		splice_acceptor_variant, intron_variant	Intron 24 of 27	5		ENSP00000343634.5		O60500-2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251476

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135912

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1461842

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727228

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Finnish congenital nephrotic syndrome

Pathogenic:2

Nov 06, 2024

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: NPHS1 c.3312-1G>C is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing and loss of NPHS1 function. Several computational tools predict a significant impact on normal splicing: Three predict the variant abolishes a 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 4e-06 in 251476 control chromosomes. c.3312-1G>C has been reported in the literature in at least one homozygous individual affected with Nephrotic Syndrome (e.g. Caridi_2009). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 19406966). ClinVar contains an entry for this variant (Variation ID: 2145832). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Feb 04, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Pathogenic:1

Jan 22, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This sequence change affects an acceptor splice site in intron 25 of the NPHS1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in NPHS1 are known to be pathogenic (PMID: 11317351, 11854170, 12039988). This variant is present in population databases (no rsID available, gnomAD 0.006%). Disruption of this splice site has been observed in individual(s) with NPHS1-related conditions (PMID: 19406966). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.50

BayesDel_noAF

Benign

-0.15

CADD

Pathogenic

DANN

Benign

0.97

Eigen

Pathogenic

0.77

Eigen_PC

Uncertain

0.55

FATHMM_MKL

Uncertain

0.95

GERP RS

4.1

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.79

SpliceAI score (max)

0.98

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.38

Position offset: -9

DS_AL_spliceai

0.98

Position offset: -1

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over