Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2BP4
The NM_000368.5(TSC1):c.2195A>T(p.His732Leu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign 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. H732Y) has been classified as Likely benign.
TSC1 (HGNC:12362): (TSC complex subunit 1) This gene is a tumor suppressor gene that encodes the growth inhibitory protein hamartin. The encoded protein interacts with and stabilizes the GTPase activating protein tuberin. This hamartin-tuberin complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. This protein also functions as a co-chaperone for Hsp90 that inhibits its ATPase activity. This protein functions as a facilitator of Hsp90-mediated folding of kinase and non-kinase clients, including TSC2 and thereby preventing their ubiquitination and proteasomal degradation. Mutations in this gene have been associated with tuberous sclerosis and lymphangioleiomyomatosis. [provided by RefSeq, May 2022]
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.H732L variant (also known as c.2195A>T), located in coding exon 15 of the TSC1 gene, results from an A to T substitution at nucleotide position 2195. The histidine at codon 732 is replaced by leucine, an amino acid with similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -
Loss of catalytic residue at N733 (P = 0.08);.;Loss of catalytic residue at N733 (P = 0.08);.;.;Loss of catalytic residue at N733 (P = 0.08);.;Loss of catalytic residue at N733 (P = 0.08);.;.;.;