16-2090196-T-G

Variant names:

• chr16-2090196-T-G
• rs1555444334
• NM_001009944.3:c.12445-2A>C

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_001009944.3(PKD1):​c.12445-2A>C variant causes a splice acceptor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 34)
• Consequence: PKD1 NM_001009944.3 splice_acceptor, intron
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 3.77

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]

MIR1225 (HGNC:33931): (microRNA 1225) 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 Pathogenic. Variant got 11 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease,
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 16-2090196-T-G is Pathogenic according to our data. Variant chr16-2090196-T-G is described in ClinVar as [Pathogenic]. Clinvar id is 434008.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PKD1	NM_001009944.3	c.12445-2A>C		splice_acceptor_variant, intron_variant	Intron 45 of 45	ENST00000262304.9	NP_001009944.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PKD1	ENST00000262304.9	c.12445-2A>C		splice_acceptor_variant, intron_variant	Intron 45 of 45	1	NM_001009944.3	ENSP00000262304.4
PKD1	ENST00000423118.5	c.12442-2A>C		splice_acceptor_variant, intron_variant	Intron 45 of 45	1		ENSP00000399501.1
MIR1225	ENST00000408729.1	n.89A>C		splice_region_variant, non_coding_transcript_exon_variant	Exon 1 of 1	6
PKD1	ENST00000472577.1	n.473-2A>C		splice_acceptor_variant, intron_variant	Intron 2 of 2	2

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 34

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Polycystic kidney disease Pathogenic:1

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Department of Pathology and Laboratory Medicine, Sinai Health System

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The PKD1 c.12445-2A>C variant was not identified in the literature nor was it identified in the Clinvitae, ClinVar, GeneInsight COGR, MutDB, ADPKD Mutation, PKD1-LOVD, and PKD1-LOVD 3.0 databases. Furthermore, the variant was not listed in the 1000 Genomes Project, the Exome Aggregation Consortium (August 8, 2016) and NHLBI GO Exome Sequencing projects nor was it identified in dbSNP. The c.12445-2A>C variant is predicted to cause abnormal splicing because the nucleotide substitution occurs in the invariant region of the splice consensus sequence. In addition, 5 of 5 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) predict a greater than 10% difference in splicing, predicting the loss of the 3’ splice site in intron 45. In summary, based on the above information, this variant meets our laboratory’s criteria to be classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	-0.070
CADD	Pathogenic	34
DANN	Benign	0.96
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.98	D
GERP RS		4.2

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.86		Position offset: -15
DS_AL_spliceai		0.98		Position offset: -2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555444334; hg19: chr16-2140197;