3-132697362-C-G

Variant names:

• chr3-132697362-C-G
• rs77533254
• NM_153240.5:c.1986G>C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_153240.5(NPHP3):​c.1986G>C​(p.Arg662Ser) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000139 in 1,441,250 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. R662R) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: NPHP3 NM_153240.5 missense, splice_region
• Scores: Splicing: ADA: 0.8755
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.70

Genes affected

NPHP3 (HGNC:7907): (nephrocystin 3) This gene encodes a protein containing a coiled-coil (CC) domain, a tubulin-tyrosine ligase (TTL) domain, and a tetratrico peptide repeat (TPR) domain. The encoded protein interacts with nephrocystin, it is required for normal ciliary development, and it functions in renal tubular development. Mutations in this gene are associated with nephronophthisis type 3, and also with renal-hepatic-pancreatic dysplasia, and Meckel syndrome type 7. Naturally occurring read-through transcripts exist between this gene and the downstream ACAD11 (acyl-CoA dehydrogenase family, member 11) gene. [provided by RefSeq, Feb 2011]

NPHP3-ACAD11 (HGNC:48351): (NPHP3-ACAD11 readthrough (NMD candidate)) This locus represents naturally occurring read-through transcription between the neighboring NPHP3 (nephronophthisis 3, adolescent) and ACAD11 (acyl-CoA dehydrogenase family, member 11) genes on chromosome 3. The read-through transcript is a candidate for nonsense-mediated mRNA decay (NMD), and is thus unlikely to produce a protein product. [provided by RefSeq, Feb 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.793

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NPHP3	NM_153240.5	c.1986G>C	p.Arg662Ser	missense_variant, splice_region_variant	Exon 14 of 27	ENST00000337331.10	NP_694972.3
NPHP3-ACAD11	NR_037804.1	n.1992G>C		splice_region_variant, non_coding_transcript_exon_variant	Exon 13 of 45

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NPHP3	ENST00000337331.10	c.1986G>C	p.Arg662Ser	missense_variant, splice_region_variant	Exon 14 of 27	1	NM_153240.5	ENSP00000338766.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000139 AC: 2 AN: 1441250 Hom.: 0 Cov.: 27 AF XY: 0.00000278 AC XY: 2 AN XY: 718480

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000195

Gnomad4 NFE exome AF: 9.13e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Nephronophthisis Uncertain:1

Feb 13, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

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, but this prediction has not been confirmed by published transcriptional studies. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with NPHP3-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with serine at codon 662 of the NPHP3 protein (p.Arg662Ser). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and serine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.18
CADD	Pathogenic	30
DANN	Benign	0.97
DEOGEN2	Benign	0.28	T
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.85	T
MetaRNN	Pathogenic	0.79	D
MetaSVM	Uncertain	-0.083	T
MutationAssessor	Benign	1.4	L
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	-1.3	N
REVEL	Uncertain	0.53
Sift	Uncertain	0.0040	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.72
MutPred		0.47		Loss of helix (P = 0.0167);
MVP		0.81
MPC		0.45
ClinPred		0.76	D
GERP RS		3.3
Varity_R		0.38
gMVP		0.55

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.88
dbscSNV1_RF	Pathogenic	0.84
SpliceAI score (max)		0.090		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs77533254; hg19: chr3-132416206;