NM_138694.4:c.977G>T

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PP3_ModeratePP5

The NM_138694.4(PKHD1):c.977G>T(p.Gly326Val) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000266 in 1,613,942 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 predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. G326G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000028 ( 0 hom. )

Consequence

PKHD1
NM_138694.4 missense, splice_region

Scores

Splicing: ADA: 0.9999

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:3

Conservation

PhyloP100: 5.24

Publications

5 publications found

Variant links:

Genes affected

PKHD1 (HGNC:9016): (PKHD1 ciliary IPT domain containing fibrocystin/polyductin) The protein encoded by this gene is predicted to have a single transmembrane (TM)-spanning domain and multiple copies of an immunoglobulin-like plexin-transcription-factor domain. Alternative splicing results in two transcript variants encoding different isoforms. Other alternatively spliced transcripts have been described, but the full length sequences have not been determined. Several of these transcripts are predicted to encode truncated products which lack the TM and may be secreted. Mutations in this gene cause autosomal recessive polycystic kidney disease, also known as polycystic kidney and hepatic disease-1. [provided by RefSeq, Jul 2008]

PKHD1 Gene-Disease associations (from GenCC):

autosomal recessive polycystic kidney disease
Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Myriad Women’s Health, Orphanet
polycystic kidney disease 4
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Laboratory for Molecular Medicine, Genomics England PanelApp
Caroli disease
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

PKHD1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_138694.4

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.

PP5

Variant 6-52062660-C-A is Pathogenic according to our data. Variant chr6-52062660-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 458610.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PKHD1	NM_138694.4 link	c.977G>T	p.Gly326Val	missense_variant, splice_region_variant	Exon 14 of 67	ENST00000371117.8	NP_619639.3	P08F94-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PKHD1	ENST00000371117.8 link	c.977G>T	p.Gly326Val	missense_variant, splice_region_variant	Exon 14 of 67	1	NM_138694.4	ENSP00000360158.3		P08F94-1
PKHD1	ENST00000340994.4 link	c.977G>T	p.Gly326Val	missense_variant, splice_region_variant	Exon 14 of 61	5		ENSP00000341097.4		P08F94-2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251218

AF XY:

0.00000737

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000881

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000280

AC:

AN:

1461762

Hom.:

Cov.:

AF XY:

0.0000261

AC XY:

AN XY:

727190

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33476

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53408

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000369

AC:

AN:

1111910

Other (OTH)

AF:

0.00

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.459

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74332

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41444

American (AMR)

AF:

0.00

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5200

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10606

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.00000756

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2Uncertain:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Autosomal recessive polycystic kidney disease

Pathogenic:2Uncertain:1

Sep 16, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jan 16, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 326 of the PKHD1 protein (p.Gly326Val). This variant is present in population databases (rs778329699, gnomAD 0.0009%). This missense change has been observed in individual(s) with autosomal recessive polycystic kidney disease (PMID: 15805161; internal data). 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: 458610). 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. 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. -

Apr 22, 2025

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: PKHD1 c.977G>T (p.Gly326Val) results in a non-conservative amino acid change located in the IPT domain (IPR002909) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. Several computational tools predict a significant impact on normal splicing: One predict the variant abolishes the canonical 3' splicing acceptor site. Three predict the variant weakens the canonical 3' splicing 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 251538 control chromosomes. c.977G>T has been observed as a biallelic genotype in individual(s) affected with autosomal recessive Polycystic Kidney And Hepatic Disease (example, Furu_2003 cited in Sharp_2005, internal data). These data indicate that the variant is 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: 15108277, 12874454, 14741187, 15805161). ClinVar contains an entry for this variant (Variation ID: 458610). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

not provided

Uncertain:1

Aug 04, 2022

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at a significant frequency in large population cohorts (gnomAD); 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: 12874454, 15805161) -

Polycystic kidney disease 4

Uncertain:1

Feb 24, 2022

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.83

BayesDel_addAF

Pathogenic

0.47

BayesDel_noAF

Pathogenic

0.44

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.82

D;.

Eigen

Pathogenic

0.84

Eigen_PC

Pathogenic

0.80

FATHMM_MKL

Uncertain

0.96

LIST_S2

Benign

0.85

D;D

M_CAP

Pathogenic

0.61

MetaRNN

Pathogenic

0.99

D;D

MetaSVM

Pathogenic

0.97

MutationAssessor

Pathogenic

3.0

M;M

PhyloP100

5.2

PrimateAI

Uncertain

0.63

PROVEAN

Pathogenic

-7.7

D;D

REVEL

Pathogenic

0.89

Sift

Pathogenic

0.0

D;D

Sift4G

Pathogenic

0.0

D;D

Polyphen

1.0

D;D

Vest4

0.97

MutPred

0.89

Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);

MVP

0.99

MPC

0.42

ClinPred

1.0

GERP RS

5.7

Varity_R

0.96

gMVP

0.94

Mutation Taster

=1/99

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.98

SpliceAI score (max)

0.47

Details are displayed if max score is > 0.2

DS_AL_spliceai

0.47

Position offset: 0

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over