16-2106622-G-T

Position:

• chr16-2106622-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The ENST00000262304.9(PKD1):​c.7265C>A​(p.Thr2422Lys) variant causes a missense change involving the alteration of a conserved nucleotide. 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 (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: PKD1 ENST00000262304.9 missense
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: 9.44

Genes affected

PKD1 (HGNC:9008): (polycystin 1, transient receptor potential channel interacting) This gene encodes a member of the polycystin protein family. The encoded glycoprotein contains a large N-terminal extracellular region, multiple transmembrane domains and a cytoplasmic C-tail. It is an integral membrane protein that functions as a regulator of calcium permeable cation channels and intracellular calcium homoeostasis. It is also involved in cell-cell/matrix interactions and may modulate G-protein-coupled signal-transduction pathways. It plays a role in renal tubular development, and mutations in this gene cause autosomal dominant polycystic kidney disease type 1 (ADPKD1). ADPKD1 is characterized by the growth of fluid-filled cysts that replace normal renal tissue and result in end-stage renal failure. Splice variants encoding different isoforms have been noted for this gene. Also, six pseudogenes, closely linked in a known duplicated region on chromosome 16p, have been described. [provided by RefSeq, Oct 2008]

MIR6511B1 (HGNC:50228): (microRNA 6511b-1) microRNAs (miRNAs) are short (20-24 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. miRNAs are transcribed by RNA polymerase II as part of capped and polyadenylated primary transcripts (pri-miRNAs) that can be either protein-coding or non-coding. The primary transcript is cleaved by the Drosha ribonuclease III enzyme to produce an approximately 70-nt stem-loop precursor miRNA (pre-miRNA), which is further cleaved by the cytoplasmic Dicer ribonuclease to generate the mature miRNA and antisense miRNA star (miRNA*) products. The mature miRNA is incorporated into a RNA-induced silencing complex (RISC), which recognizes target mRNAs through imperfect base pairing with the miRNA and most commonly results in translational inhibition or destabilization of the target mRNA. The RefSeq represents the predicted microRNA stem-loop. [provided by RefSeq, Sep 2009]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in ENST00000262304.9
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.942

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PKD1	NM_001009944.3	c.7265C>A	p.Thr2422Lys	missense_variant	18/46	ENST00000262304.9	NP_001009944.3
MIR6511B1	NR_106775.1			downstream_gene_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PKD1	ENST00000262304.9	c.7265C>A	p.Thr2422Lys	missense_variant	18/46	1	NM_001009944.3	ENSP00000262304	P5
MIR6511B1	ENST00000612014.1			downstream_gene_variant

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 1446338 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 720044

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

Submissions by phenotype

Polycystic kidney disease Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The PKD1 p.Thr2422Lys variant was identified in 2 of 214 proband chromosomes (frequency: 0.009) from individuals or families with polycystic kidney disease and classified probably pathogenic (Garcia-Gonzalez 2007, Tan 2009). The variant was also identified in ADPKD Mutation Database and classified as highly likely pathogenic. The variant was not identified in dbSNP, NHLBI GO Exome Sequencing Project, the Exome Aggregation Consortium database, Clinvitae, ClinVar, GeneInsight COGR, PKD1-LOVD, and PKD1-LOVD 3.0 databases. The p.Thr2422 residue is conserved across mammals and other organisms, and four of five computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) suggest that the variant may impact the protein; however, this information is not predictive enough to assume pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) do not predict a difference in splicing. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.090
CADD	Uncertain	26
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.78	D;.
Eigen	Pathogenic	0.72
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.83	T;T
M_CAP	Pathogenic	0.93	D
MetaRNN	Pathogenic	0.94	D;D
MetaSVM	Uncertain	0.35	D
MutationAssessor	Uncertain	2.7	M;M
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-4.5	D;D
REVEL	Pathogenic	0.74
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.82
MutPred		0.66		Gain of ubiquitination at T2422 (P = 0.0082);Gain of ubiquitination at T2422 (P = 0.0082);
MVP		0.93
ClinPred		0.99	D
GERP RS		4.8
Varity_R		0.86
gMVP		0.90

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: rs1555453210; hg19: chr16-2156623;