rs775831255

Variant names:

• chr6-51903597-C-T
• rs775831255
• NM_138694.4:c.6996G>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_138694.4(PKHD1):​c.6996G>A​(p.Glu2332Glu) 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
• Publications: 0 publications found

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: Laboratory for Molecular Medicine, G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• Caroli disease

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_138694.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PKHD1	NM_138694.4	MANE Select	c.6996G>A	p.Glu2332Glu	splice_region synonymous	Exon 43 of 67	NP_619639.3
	PKHD1	NM_170724.3		c.6996G>A	p.Glu2332Glu	splice_region synonymous	Exon 43 of 61	NP_733842.2	P08F94-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PKHD1	ENST00000371117.8	TSL:1 MANE Select	c.6996G>A	p.Glu2332Glu	splice_region synonymous	Exon 43 of 67	ENSP00000360158.3	P08F94-1
	PKHD1	ENST00000340994.4	TSL:5	c.6996G>A	p.Glu2332Glu	splice_region synonymous	Exon 43 of 61	ENSP00000341097.4	P08F94-2

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

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33316

American (AMR) AF: 0.00 AC: 0 AN: 44652

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25948

East Asian (EAS) AF: 0.00 AC: 0 AN: 39548

South Asian (SAS) AF: 0.00 AC: 0 AN: 86208

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53098

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5738

European-Non Finnish (NFE) AF: 9.02e-7 AC: 1 AN: 1108946

Other (OTH) AF: 0.00 AC: 0 AN: 60116

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 31

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Autosomal recessive polycystic kidney disease (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.32
CADD	Benign	18
DANN	Benign	0.84
PhyloP100		4.4

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

Other links and lift over

dbSNP: rs775831255; hg19: chr6-51768395;