6-52050158-G-C

Variant names:

• chr6-52050158-G-C
• rs9370096
• NM_138694.4:c.2278C>G

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 6P and 2B. PM1 PM2 PM5 BP4_Moderate

The NM_138694.4(PKHD1):​c.2278C>G​(p.Arg760Gly) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,600 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 18/26 in silico tools predict a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R760H) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PKHD1 NM_138694.4 missense, splice_region
• Scores: Splicing: ADA: 0.0002755
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.479
• 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 4 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 9 uncertain in NM_138694.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-52050157-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 188876.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP4: Computational evidence support a benign effect (MetaRNN=0.099618345).

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.2278C>G	p.Arg760Gly	missense splice_region	Exon 22 of 67	NP_619639.3
	PKHD1	NM_170724.3		c.2278C>G	p.Arg760Gly	missense splice_region	Exon 22 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.2278C>G	p.Arg760Gly	missense splice_region	Exon 22 of 67	ENSP00000360158.3	P08F94-1
	PKHD1	ENST00000340994.4	TSL:5	c.2278C>G	p.Arg760Gly	missense splice_region	Exon 22 of 61	ENSP00000341097.4	P08F94-2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461600 Hom.: 0 Cov.: 46 AF XY: 0.00000138 AC XY: 1 AN XY: 727080

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39680

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5690

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111872

Other (OTH) AF: 0.00 AC: 0 AN: 60372

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.083
BayesDel_addAF	Benign	-0.072	T
BayesDel_noAF	Benign	-0.34
CADD	Benign	5.2
DANN	Benign	0.93
DEOGEN2	Benign	0.13	T
Eigen	Benign	-0.97
Eigen_PC	Benign	-1.0
FATHMM_MKL	Benign	0.027	N
LIST_S2	Benign	0.74	T
M_CAP	Benign	0.061	D
MetaRNN	Benign	0.10	T
MetaSVM	Benign	-0.73	T
MutationAssessor	Benign	1.0	L
PhyloP100		-0.48
PrimateAI	Benign	0.20	T
PROVEAN	Benign	1.1	N
REVEL	Benign	0.27
Sift	Benign	0.67	T
Sift4G	Benign	0.57	T
Polyphen		0.56	P
Vest4		0.24
MutPred		0.43		Loss of sheet (P = 0.0084)
MVP		0.77
MPC		0.10
ClinPred		0.26	T
GERP RS		-6.3
Varity_R		0.076
gMVP		0.53
Mutation Taster		=94/6	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00028
dbscSNV1_RF	Benign	0.010
SpliceAI score (max)		0.25		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.25		Position offset: -1

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

Other links and lift over

dbSNP: rs9370096; hg19: chr6-51914956;