Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2PP3BP6
The NM_000548.5(TSC2):c.5374C>A(p.Gln1792Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,610,722 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q1792H) has been classified as Benign.
TSC2 (HGNC:12363): (TSC complex subunit 2) This gene is a tumor suppressor gene that encodes the growth inhibitory protein tuberin. Tuberin interacts with hamartin to form the TSC protein complex which functions in the control of cell growth. This TSC protein complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. Mutations in this gene have been associated with tuberous sclerosis and lymphangioleiomyomatosis. [provided by RefSeq, May 2022]
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]
Verdict is Uncertain_significance. Variant got 2 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.828
BP6
Variant 16-2088560-C-A is Benign according to our data. Variant chr16-2088560-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 405999.We mark this variant Likely_benign, oryginal submissions are: {Benign=1, Uncertain_significance=2}.
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.Q1792K variant (also known as c.5374C>A), located in coding exon 41 of the TSC2 gene, results from a C to A substitution at nucleotide position 5374. The glutamine at codon 1792 is replaced by lysine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -