rs1554227162

Positions:

• chr6-52079898-AC-A

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Moderate PM2 PP3_Moderate PP5_Very_Strong

The NM_138694.4(PKHD1):​c.390+1del variant causes a splice donor change. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PKHD1 NM_138694.4 splice_donor
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 4.16

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 14 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.0088343555 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.8, offset of 0 (no position change), new splice context is: caaGTgggt. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 6-52079898-AC-A is Pathogenic according to our data. Variant chr6-52079898-AC-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 556777.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PKHD1	NM_138694.4	c.390+1del		splice_donor_variant		ENST00000371117.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PKHD1	ENST00000371117.8	c.390+1del		splice_donor_variant		1	NM_138694.4	P2
PKHD1	ENST00000340994.4	c.390+1del		splice_donor_variant		5		A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 23

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Autosomal recessive polycystic kidney disease Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jul 19, 2022	This sequence change creates a premature translational stop signal (p.Lys130Asnfs*23) in the PKHD1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in PKHD1 are known to be pathogenic (PMID: 19940839). This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with clinical features of PKHD1-related conditions (PMID: 33282801; Invitae). This variant is also known as c.390+1del. ClinVar contains an entry for this variant (Variation ID: 556777). 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. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Feb 20, 2018	- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.94		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.68		Position offset: -21
DS_DL_spliceai		0.94		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1554227162; hg19: chr6-51944696;