Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP2
The NM_000368.5(TSC1):c.1672C>A(p.Pro558Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,460,130 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P558S) has been classified as Uncertain significance.
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]
Verdict is Uncertain_significance. Variant got 3 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TSC1. . Gene score misZ 2.3217 (greater than the threshold 3.09). Trascript score misZ 3.6986 (greater than threshold 3.09). GenCC has associacion of gene with lung lymphangioleiomyomatosis, tuberous sclerosis 1, tuberous sclerosis, tuberous sclerosis complex, lymphangioleiomyomatosis.
Gain of glycosylation at P558 (P = 0.0235);.;Gain of glycosylation at P558 (P = 0.0235);.;.;Gain of glycosylation at P558 (P = 0.0235);.;Gain of glycosylation at P558 (P = 0.0235);.;Gain of glycosylation at P558 (P = 0.0235);.;