rs745770404

chr6-52050157-C-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1 PM2 PP3_Strong PP5_Very_Strong

The NM_138694.4(PKHD1):c.2279G>A(p.Arg760His) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000112 in 1,613,866 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/2 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R760C) has been classified as Benign.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000011 (0 hom.)
• Consequence: PKHD1 NM_138694.4 missense, splice_region
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 4.89

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]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 6 uncertain in NM_138694.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 6-52050157-C-T is Pathogenic according to our data. Variant chr6-52050157-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 188876.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr6-52050157-C-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PKHD1	NM_138694.4	c.2279G>A	p.Arg760His	missense_variant, splice_region_variant	22/67	ENST00000371117.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PKHD1	ENST00000371117.8	c.2279G>A	p.Arg760His	missense_variant, splice_region_variant	22/67	1	NM_138694.4	P2
PKHD1	ENST00000340994.4	c.2279G>A	p.Arg760His	missense_variant, splice_region_variant	22/61	5		A2

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152196 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251138 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135728

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

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: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000109 AC: 16 AN: 1461670 Hom.: 0 Cov.: 32 AF XY: 0.0000110 AC XY: 8 AN XY: 727124

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000894

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000719

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152196 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74350

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000481 Hom.: 0

Bravo AF: 0.0000113

ExAC AF: 0.0000247 AC: 3

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Autosomal recessive polycystic kidney disease Pathogenic:5

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 25, 2024	This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 760 of the PKHD1 protein (p.Arg760His). This variant also falls at the last nucleotide of exon 22, which is part of the consensus splice site for this exon. This variant is present in population databases (rs745770404, gnomAD 0.006%). This missense change has been observed in individual(s) with autosomal recessive polycystic kidney disease (PMID: 11898128, 15698423, 20413436). 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: 188876). 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. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this missense change alters mRNA splicing and is expected to lead to the loss of protein expression (PMID: 24984783). For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Jul 11, 2014	- -
Likely pathogenic, criteria provided, single submitter	research	Molecular Biology Laboratory, Fundació Puigvert	Feb 01, 2020	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Jul 28, 2018	- -
Pathogenic, criteria provided, single submitter	research	Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard	-	The heterozygous p.Arg760His variant was identified in the compound heterozygous state by our study in one individual with autosomal recessive polycystic kidney disease. The p.Arg760His variant is believed to be pathogenic based on numberous reports by other laboratories in the literature (Onuchic 2002, Bergmann 2005, Sharp 2005, Gunay-Aygun 2010). -

Polycystic kidney disease 4 Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 05, 2019	This variant was determined to be pathogenic according to ACMG Guidelines, 2015 [PMID:25741868]. -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center	Mar 26, 2024	- -
Pathogenic, no assertion criteria provided	clinical testing	Biochemical Molecular Genetic Laboratory, King Abdulaziz Medical City	Sep 10, 2020	- -

PKHD1-related condition Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Oct 31, 2023

The PKHD1 c.2279G>A variant is predicted to result in the amino acid substitution p.Arg760His. This substitution occurs at the last nucleotide of exon 22 and is predicted to substantially affect normal splicing by available splicing prediction programs (Alamut Visual Plus v1.6.1). This variant has been reported in individuals with autosomal recessive polycystic kidney disease (ARPKD) (Onuchic et al. 2002. PubMed ID: 11898128; Jordan et al. 2022. PubMed ID: 35005812). Of note, we have previously observed this variant at PreventionGenetics in the homozygous state in an affected child and the heterozygous state in other PKD patients who have another pathogenic PKHD1 variant. The c.2279G>A variant is reported in 0.0058% of alleles in individuals of Latino descent in gnomAD (http://gnomad.broadinstitute.org/variant/6-51914955-C-T). This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.073
BayesDel_addAF	Uncertain	0.022	T
BayesDel_noAF	Uncertain	-0.030
Cadd	Uncertain	25
Dann	Pathogenic	1.0
DEOGEN2	Benign	0.34	T;.
Eigen	Uncertain	0.50
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Benign	0.72	D
LIST_S2	Benign	0.69	T;T
M_CAP	Benign	0.074	D
MetaRNN	Benign	0.29	T;T
MetaSVM	Uncertain	-0.061	T
MutationAssessor	Benign	1.4	L;L
MutationTaster	Benign	0.79	D;D
PrimateAI	Benign	0.20	T
PROVEAN	Benign	-1.3	N;N
REVEL	Uncertain	0.49
Sift	Benign	0.53	T;T
Sift4G	Benign	0.075	T;T
Polyphen		0.99	D;D
Vest4		0.16
MVP		0.96
MPC		0.22
ClinPred		0.93	D
GERP RS		5.6
Varity_R		0.056
gMVP		0.37

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.54		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.54		Position offset: 0

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

Publications

LitVar

Other links and lift over

dbSNP: rs745770404; hg19: chr6-51914955; COSMIC: COSV61868056;