rs1057516445

Positions:

• chr6-51747933-G-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_138694.4(PKHD1):​c.9683C>A​(p.Ser3228*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,790 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: PKHD1 NM_138694.4 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 1.64

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 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 6-51747933-G-T is Pathogenic according to our data. Variant chr6-51747933-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 370381.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr6-51747933-G-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PKHD1	NM_138694.4	c.9683C>A	p.Ser3228*	stop_gained	58/67	ENST00000371117.8	NP_619639.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PKHD1	ENST00000371117.8	c.9683C>A	p.Ser3228*	stop_gained	58/67	1	NM_138694.4	ENSP00000360158.3
PKHD1	ENST00000340994.4	c.9683C>A	p.Ser3228*	stop_gained	58/61	5		ENSP00000341097.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461790 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727202

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: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Autosomal recessive polycystic kidney disease Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Mar 14, 2020	Loss-of-function variants in PKHD1 are known to be pathogenic (PMID: 19940839). This variant has been observed in individual(s) with autosomal recessive polycystic kidney disease (PMID: 16133180). ClinVar contains an entry for this variant (Variation ID: 370381). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Ser3228*) in the PKHD1 gene. It is expected to result in an absent or disrupted protein product. For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Jan 28, 2016	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jul 11, 2021	Variant summary: PKHD1 c.9683C>A (p.Ser3228X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 251218 control chromosomes. c.9683C>A has been reported in the literature in at-least one compound heterozygote individual affected with Polycystic Kidney Disease (example, Losekoot_2005). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic (n=1)/likely pathogenic (n=1). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.29
CADD	Pathogenic	38
DANN	Uncertain	0.99
Eigen	Uncertain	0.38
Eigen_PC	Benign	0.13
FATHMM_MKL	Benign	0.56	D
Vest4		0.94
GERP RS		2.8

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

Publications

LitVar

Other links and lift over

dbSNP: rs1057516445; hg19: chr6-51612731;