Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3
The NM_001908.5(CTSB):c.967T>G(p.Ser323Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).
CTSB (HGNC:2527): (cathepsin B) This gene encodes a member of the C1 family of peptidases. Alternative splicing of this gene results in multiple transcript variants. At least one of these variants encodes a preproprotein that is proteolytically processed to generate multiple protein products. These products include the cathepsin B light and heavy chains, which can dimerize to form the double chain form of the enzyme. This enzyme is a lysosomal cysteine protease with both endopeptidase and exopeptidase activity that may play a role in protein turnover. It is also known as amyloid precursor protein secretase and is involved in the proteolytic processing of amyloid precursor protein (APP). Incomplete proteolytic processing of APP has been suggested to be a causative factor in Alzheimer's disease, the most common cause of dementia. Overexpression of the encoded protein has been associated with esophageal adenocarcinoma and other tumors. Both Cathepsin B and Cathepsin L are involved in the cleavage of the spike protein from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) upon its entry to the human host cell. Multiple pseudogenes of this gene have been identified. [provided by RefSeq, Sep 2020]
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The c.967T>G (p.S323A) alteration is located in exon 10 (coding exon 9) of the CTSB gene. This alteration results from a T to G substitution at nucleotide position 967, causing the serine (S) at amino acid position 323 to be replaced by an alanine (A). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Loss of catalytic residue at S323 (P = 0.0376);Loss of catalytic residue at S323 (P = 0.0376);Loss of catalytic residue at S323 (P = 0.0376);Loss of catalytic residue at S323 (P = 0.0376);Loss of catalytic residue at S323 (P = 0.0376);Loss of catalytic residue at S323 (P = 0.0376);Loss of catalytic residue at S323 (P = 0.0376);