16-2090196-TGGGGGCGGCACAGGG-T

Variant names:

• chr16-2090196-TGGGGGCGGCACAGGG-T
• NM_001009944.3:c.12445-17_12445-3delCCCTGTGCCGCCCCC

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001009944.3(PKD1):​c.12445-17_12445-3delCCCTGTGCCGCCCCC variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 34)
• Consequence: PKD1 NM_001009944.3 splice_region, intron
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.38

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 Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PKD1	NM_001009944.3	c.12445-17_12445-3delCCCTGTGCCGCCCCC		splice_region_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.12445-17_12445-3delCCCTGTGCCGCCCCC		splice_region_variant, intron_variant	Intron 45 of 45	1	NM_001009944.3	ENSP00000262304.4
PKD1	ENST00000423118.5	c.12442-17_12442-3delCCCTGTGCCGCCCCC		splice_region_variant, intron_variant	Intron 45 of 45	1		ENSP00000399501.1
MIR1225	ENST00000408729.1	n.74_88delCCCTGTGCCGCCCCC		splice_region_variant, non_coding_transcript_exon_variant	Exon 1 of 1	6
PKD1	ENST00000472577.1	n.473-17_473-3delCCCTGTGCCGCCCCC		splice_region_variant, intron_variant	Intron 2 of 2	2

Frequencies

GnomAD3 genomes Cov.: 34

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 34

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Polycystic kidney disease, adult type Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	Oct 10, 2024	Based on the classification scheme VCGS_Germline_v1.3.5, this variant is classified as VUS-3A. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with polycystic kidney disease 1 (PKD; MIM#173900). (I) 0107 - This gene is associated with autosomal dominant disease. Polycystic kidney disease 1 (MIM#173900) is predominantly caused by monoallelic variants, with rare reports of biallelic variants causing disease (OMIM). (I) 0212 - Non-canonical splice site variant without proven consequence on splicing (no functional evidence available). (SP) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (v2, v3 and v4). (SP) 0505 - Abnormal splicing is predicted by in silico tools and affected nucleotide is highly conserved. (SP) 0705 - No comparable splice variants have previous evidence for pathogenicity. However, another deletion in the same intron affecting overlapping nucleotides has been reported in a large pedigree with autosomal dominant PKD and was shown to activate a cryptic 3' splice site resulting in a frameshift variant; therefore it was regarded as pathogenic (PMID: 11058904, ADPKD database). (I) 0807 - This variant has no previous evidence of pathogenicity. (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Uncertain significance, criteria provided, single submitter	clinical testing	Molecular Genetics, Royal Melbourne Hospital	Mar 30, 2023	This sequence change deletes 15 bp in the splice region of the acceptor site of intron 45 of PKD1. It is absent in a large population cohort (gnomAD v2.1). The nucleotides in the deleted region are moderately to not conserved (100 vertebrates, UCSC), and multiple lines of computational evidence predict an impact on splicing (HSF, MaxEntScan, NNSplice). The predicted effect is loss of the acceptor splice site and activation of a cryptic acceptor site leading to the in-frame retention of 24 bp (excluding the 15 bp deletion) of intron 45, and the insertion of 8 amino acids in the heterotrimeric G-protein binding sequence in the C-terminal cytoplasmic domain (PMID: 20837139). This variant is not reported in relevant medical literature or in the PKD1 mutation database. Based on the classification scheme RMH ACMG Guidelines v1.1.1, this variant is classified as a VARIANT of UNCERTAIN SIGNIFICANCE. Following criteria are met: PM2, PP3. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr16-2140197;