rs775831255

Positions:

• chr6-51903597-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_138694.4(PKHD1):​c.6996G>A​(p.Glu2332=) variant causes a splice region, synonymous change. The variant allele was found at a frequency of 0.000000686 in 1,457,570 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: PKHD1 NM_138694.4 splice_region, synonymous
• Scores: Splicing: ADA: 0.9995
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.43

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PKHD1	NM_138694.4	c.6996G>A	p.Glu2332=	splice_region_variant, synonymous_variant	43/67	ENST00000371117.8	NP_619639.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PKHD1	ENST00000371117.8	c.6996G>A	p.Glu2332=	splice_region_variant, synonymous_variant	43/67	1	NM_138694.4	ENSP00000360158	P2
PKHD1	ENST00000340994.4	c.6996G>A	p.Glu2332=	splice_region_variant, synonymous_variant	43/61	5		ENSP00000341097	A2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1457570 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 725252

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: 9.02e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Autosomal recessive polycystic kidney disease Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 06, 2015

In summary, this is a novel silent change with uncertain impact on splicing. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of silent changes on mRNA splicing suggest that this variant may alter mRNA splicing, but this prediction has not been confirmed by published transcriptional studies. This variant has not been published in the literature and is not present in population databases. This sequence change affects codon 2332 of the PKHD1 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the PKHD1 protein. It also falls at the last nucleotide of exon 43 of the PKHD1 mRNA. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.32
CADD	Benign	18
DANN	Benign	0.84

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.97
SpliceAI score (max)		0.72		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.72		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: rs775831255; hg19: chr6-51768395;