2-110178520-A-G

Variant names:

• chr2-110178520-A-G
• rs140446520
• NM_001128178.3:c.232T>C

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The NM_001128178.3(NPHP1):​c.232T>C​(p.Tyr78His) variant causes a missense change. The variant allele was found at a frequency of 0.00197 in 1,613,778 control chromosomes in the GnomAD database, including 17 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0012 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0020 (17 hom.)
• Consequence: NPHP1 NM_001128178.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8 B:3
• Conservation: PhyloP100: 5.99
• Publications: 9 publications found

Genes affected

NPHP1 (HGNC:7905): (nephrocystin 1) This gene encodes a protein with src homology domain 3 (SH3) patterns. This protein interacts with Crk-associated substrate, and it appears to function in the control of cell division, as well as in cell-cell and cell-matrix adhesion signaling, likely as part of a multifunctional complex localized in actin- and microtubule-based structures. Mutations in this gene cause familial juvenile nephronophthisis type 1, a kidney disorder involving both tubules and glomeruli. Defects in this gene are also associated with Senior-Loken syndrome type 1, also referred to as juvenile nephronophthisis with Leber amaurosis, which is characterized by kidney and eye disease, and with Joubert syndrome type 4, which is characterized by cerebellar ataxia, oculomotor apraxia, psychomotor delay and neonatal breathing abnormalities, sometimes including retinal dystrophy and renal disease. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

NPHP1 Gene-Disease associations (from GenCC):

• Joubert syndrome with renal defect

  Inheritance: AR Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, G2P
• nephronophthisis 1

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, ClinGen, Labcorp Genetics (formerly Invitae)
• Bardet-Biedl syndrome

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

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Benign. The variant received -9 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.010531783).
• BS1: Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.00122 (186/152314) while in subpopulation NFE AF = 0.00212 (144/68026). AF 95% confidence interval is 0.00183. There are 0 homozygotes in GnomAd4. There are 87 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High Homozygotes in GnomAdExome4 at 17 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NPHP1	NM_001128178.3	c.232T>C	p.Tyr78His	missense_variant	Exon 4 of 20	ENST00000445609.7	NP_001121650.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NPHP1	ENST00000445609.7	c.232T>C	p.Tyr78His	missense_variant	Exon 4 of 20	1	NM_001128178.3	ENSP00000389879.3

Frequencies

GnomAD3 genomes AF: 0.00122 AC: 186 AN: 152196 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000507

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

Gnomad ASJ AF: 0.00461

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00212

Gnomad OTH AF: 0.000479

GnomAD2 exomes AF: 0.00133 AC: 333 AN: 251250 AF XY: 0.00130

Gnomad AFR exome AF: 0.000431

Gnomad AMR exome AF: 0.000347

Gnomad ASJ exome AF: 0.00546

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000924

Gnomad NFE exome AF: 0.00212

Gnomad OTH exome AF: 0.000653

GnomAD4 exome AF: 0.00204 AC: 2986 AN: 1461464 Hom.: 17 Cov.: 30 AF XY: 0.00202 AC XY: 1467 AN XY: 727038

African (AFR) AF: 0.000269 AC: 9 AN: 33474

American (AMR) AF: 0.000537 AC: 24 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00551 AC: 144 AN: 26124

East Asian (EAS) AF: 0.00 AC: 0 AN: 39654

South Asian (SAS) AF: 0.000487 AC: 42 AN: 86234

European-Finnish (FIN) AF: 0.0000749 AC: 4 AN: 53372

Middle Eastern (MID) AF: 0.000347 AC: 2 AN: 5764

European-Non Finnish (NFE) AF: 0.00241 AC: 2684 AN: 1111746

Other (OTH) AF: 0.00128 AC: 77 AN: 60380

GnomAD4 genome AF: 0.00122 AC: 186 AN: 152314 Hom.: 0 Cov.: 32 AF XY: 0.00117 AC XY: 87 AN XY: 74480

African (AFR) AF: 0.000505 AC: 21 AN: 41576

American (AMR) AF: 0.000196 AC: 3 AN: 15300

Ashkenazi Jewish (ASJ) AF: 0.00461 AC: 16 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5190

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10606

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00212 AC: 144 AN: 68026

Other (OTH) AF: 0.000474 AC: 1 AN: 2110

Alfa AF: 0.00181 Hom.: 4

Bravo AF: 0.00132

TwinsUK AF: 0.00378 AC: 14

ALSPAC AF: 0.00104 AC: 4

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00198 AC: 17

ExAC AF: 0.00122 AC: 148

Asia WGS AF: 0.000289 AC: 1 AN: 3476

EpiCase AF: 0.00169

EpiControl AF: 0.00166

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:8 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Nephronophthisis 1 Uncertain:2

Apr 30, 2019

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was classified as: Uncertain significance. -

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not provided Uncertain:2

Jul 15, 2025

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 32483926, 34426522, 30108342, 37296294) -

Jan 27, 2023

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

BS1, BP4 -

not specified Uncertain:1 Benign:1

Jul 06, 2022

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: NPHP1 c.232T>C (p.Tyr78His) results in a conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0013 in 251250 control chromosomes (gnomAD), predominantly at a frequency of 0.0021 within the Non-Finnish European subpopulation in the gnomAD database, including 1 homozygote. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database is approximately 4 fold of the estimated maximal expected allele frequency for a pathogenic variant in NPHP1 causing Joubert Syndrome And Related Disorders phenotype (0.00056), strongly suggesting that the variant is a benign polymorphism found primarily in populations of Non-Finnish European origin. c.232T>C has been reported in the literature in two individuals affected with periventricular pseudocysts in utero, these individuals also carried a full gene deletion in trans (Reches_2018). 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. Six ClinVar submitters have assessed the variant since 2014: four classified the variant as of uncertain significance, and two as likely benign. Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -

May 25, 2018

Eurofins Ntd Llc (ga)

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Senior-Loken syndrome 1 Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Joubert syndrome with renal defect Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Joubert syndrome with renal defect;C1855681:Nephronophthisis 1;C4551559:Senior-Loken syndrome 1 Uncertain:1

May 23, 2017

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

NPHP1-related disorder Benign:1

Aug 06, 2024

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Nephronophthisis Benign:1

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.61
BayesDel_addAF	Benign	-0.21	T
BayesDel_noAF	Uncertain	-0.080
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.37	.;.;T;T;.
Eigen	Uncertain	0.48
Eigen_PC	Uncertain	0.38
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.88	D;D;D;D;D
M_CAP	Uncertain	0.11	D
MetaRNN	Benign	0.011	T;T;T;T;T
MetaSVM	Uncertain	-0.13	T
MutationAssessor	Uncertain	2.7	M;M;M;.;.
PhyloP100		6.0
PrimateAI	Uncertain	0.55	T
PROVEAN	Benign	-2.2	N;N;N;N;D
REVEL	Benign	0.19
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Benign	0.11	T;T;T;T;T
Polyphen		1.0	D;D;D;D;D
Vest4		0.42
MVP		0.88
MPC		0.50
ClinPred		0.056	T
GERP RS		5.6
Varity_R		0.49
gMVP		0.28
Mutation Taster		=47/53	disease causing

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: rs140446520; hg19: chr2-110936097;