Our verdict is Likely benign. Variant got -2 ACMG points: 3P and 5B. PM5PP3BP6BS2
The NM_000548.5(TSC2):c.3718C>T(p.Arg1240Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000479 in 1,460,610 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. R1240W) has been classified as Likely pathogenic.
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]
Verdict is Likely_benign. Variant got -2 ACMG points.
PM5
Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.762
BP6
Variant 16-2081702-C-T is Benign according to our data. Variant chr16-2081702-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 50015.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1, not_provided=1}. Variant chr16-2081702-C-T is described in Lovd as [Benign]. Variant chr16-2081702-C-T is described in Lovd as [Likely_benign].
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.R1240C variant (also known as c.3718C>T), located in coding exon 30 of the TSC2 gene, results from a C to T substitution at nucleotide position 3718. The arginine at codon 1240 is replaced by cysteine, an amino acid with highly dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Tuberous sclerosis 2 Benign:1
Oct 10, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter