chr1-5978347-G-T

Variant names:

• chr1-5978347-G-T
• rs771873685
• NM_015102.5:c.202C>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_015102.5(NPHP4):​c.202C>A​(p.Arg68Arg) variant causes a synonymous change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 29)
• Consequence: NPHP4 NM_015102.5 synonymous
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.03
• Publications: 0 publications found

Genes affected

NPHP4 (HGNC:19104): (nephrocystin 4) This gene encodes a protein involved in renal tubular development and function. This protein interacts with nephrocystin, and belongs to a multifunctional complex that is localized to actin- and microtubule-based structures. Mutations in this gene are associated with nephronophthisis type 4, a renal disease, and with Senior-Loken syndrome type 4, a combination of nephronophthisis and retinitis pigmentosa. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Apr 2014]

NPHP4 Gene-Disease associations (from GenCC):

• nephronophthisis 4

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), G2P
• Senior-Loken syndrome 4

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• nephronophthisis 1

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Senior-Loken syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NPHP4	NM_015102.5	c.202C>A	p.Arg68Arg	synonymous_variant	Exon 3 of 30	ENST00000378156.9	NP_055917.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NPHP4	ENST00000378156.9	c.202C>A	p.Arg68Arg	synonymous_variant	Exon 3 of 30	1	NM_015102.5	ENSP00000367398.4
NPHP4	ENST00000378169.7	n.202C>A		non_coding_transcript_exon_variant	Exon 3 of 27	1		ENSP00000367411.3
NPHP4	ENST00000489180.6	n.202C>A		non_coding_transcript_exon_variant	Exon 3 of 33	2		ENSP00000423747.1

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 29

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Nephronophthisis Uncertain:1

Feb 01, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, this is a novel silent change with uncertain impact on splicing. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may alter RNA splicing, but this prediction has not been confirmed by published transcriptional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a NPHP4-related disease. This sequence change affects codon 68 of the NPHP4 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the NPHP4 protein. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.41
CADD	Uncertain	24
DANN	Benign	0.71
PhyloP100		4.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.85		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.85		Position offset: -2

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

Other links and lift over

dbSNP: rs771873685; hg19: chr1-6038407;