Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2
The NM_000548.5(TSC2):c.299C>A(p.Ala100Glu) variant causes a missense change. The variant allele was found at a frequency of 0.000000698 in 1,433,568 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. A100V) 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]
TSC2 Gene-Disease associations (from GenCC):
tuberous sclerosis
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
tuberous sclerosis 2
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Ambry Genetics
lymphangioleiomyomatosis
Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
tuberous sclerosis complex
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
32930
American (AMR)
AF:
0.00
AC:
0
AN:
40718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25558
East Asian (EAS)
AF:
0.0000261
AC:
1
AN:
38248
South Asian (SAS)
AF:
0.00
AC:
0
AN:
81950
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50426
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5490
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1098972
Other (OTH)
AF:
0.00
AC:
0
AN:
59276
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Gain of disorder (P = 0.0493);Gain of disorder (P = 0.0493);Gain of disorder (P = 0.0493);.;Gain of disorder (P = 0.0493);Gain of disorder (P = 0.0493);Gain of disorder (P = 0.0493);Gain of disorder (P = 0.0493);Gain of disorder (P = 0.0493);.;Gain of disorder (P = 0.0493);Gain of disorder (P = 0.0493);Gain of disorder (P = 0.0493);Gain of disorder (P = 0.0493);.;