6-51747891-C-G

Variant names:

• chr6-51747891-C-G
• rs886044327
• NM_138694.4:c.9725G>C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PM5 PP3_Moderate

The NM_138694.4(PKHD1):​c.9725G>C​(p.Gly3242Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G3242V) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PKHD1 NM_138694.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.16

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-51747891-C-A is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.865

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PKHD1	NM_138694.4	c.9725G>C	p.Gly3242Ala	missense_variant	Exon 58 of 67	ENST00000371117.8	NP_619639.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PKHD1	ENST00000371117.8	c.9725G>C	p.Gly3242Ala	missense_variant	Exon 58 of 67	1	NM_138694.4	ENSP00000360158.3
PKHD1	ENST00000340994.4	c.9725G>C	p.Gly3242Ala	missense_variant	Exon 58 of 61	5		ENSP00000341097.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Autosomal recessive polycystic kidney disease Uncertain:1

Jun 16, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine with alanine at codon 3242 of the PKHD1 protein (p.Gly3242Ala). The glycine residue is moderately conserved and there is a small physicochemical difference between glycine and alanine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with a PKHD1-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, this variant has uncertain impact on PKHD1 function. The available evidence is currently insufficient to determine its role in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.31
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.34
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.69	D;.
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.86	D;D
M_CAP	Uncertain	0.19	D
MetaRNN	Pathogenic	0.87	D;D
MetaSVM	Pathogenic	0.83	D
MutationAssessor	Uncertain	2.8	M;M
PrimateAI	Uncertain	0.53	T
PROVEAN	Pathogenic	-5.2	D;D
REVEL	Pathogenic	0.78
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.92
MutPred		0.59		Gain of sheet (P = 0.0827);Gain of sheet (P = 0.0827);
MVP		0.96
MPC		0.39
ClinPred		0.99	D
GERP RS		5.7
Varity_R		0.89
gMVP		0.87

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: rs886044327; hg19: chr6-51612689;