Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1PM2PM5PP2PP3_Strong
The NM_000021.4(PSEN1):āc.767A>Cā(p.Tyr256Ser) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as not provided (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y256N) has been classified as Pathogenic.
PSEN1 (HGNC:9508): (presenilin 1) Alzheimer's disease (AD) patients with an inherited form of the disease carry mutations in the presenilin proteins (PSEN1; PSEN2) or in the amyloid precursor protein (APP). These disease-linked mutations result in increased production of the longer form of amyloid-beta (main component of amyloid deposits found in AD brains). Presenilins are postulated to regulate APP processing through their effects on gamma-secretase, an enzyme that cleaves APP. Also, it is thought that the presenilins are involved in the cleavage of the Notch receptor, such that they either directly regulate gamma-secretase activity or themselves are protease enzymes. Several alternatively spliced transcript variants encoding different isoforms have been identified for this gene, the full-length nature of only some have been determined. [provided by RefSeq, Aug 2008]
PSEN1 Gene-Disease associations (from GenCC):
Alzheimer disease 3
Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
Pick disease
Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
semantic dementia
Inheritance: AD Classification: STRONG, LIMITED Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
behavioral variant of frontotemporal dementia
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
early-onset autosomal dominant Alzheimer disease
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
familial isolated dilated cardiomyopathy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
acne inversa, familial, 3
Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
dilated cardiomyopathy 1U
Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
dilated cardiomyopathy
Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
Our verdict: Pathogenic. The variant received 11 ACMG points.
PM1
In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 4 uncertain in NM_000021.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr14-73192861-T-A is described in ClinVar as Pathogenic. ClinVar VariationId is 2419054.Status of the report is criteria_provided_single_submitter, 1 stars.
PP2
Missense variant in the PSEN1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 113 curated pathogenic missense variants (we use a threshold of 10). The gene has 14 curated benign missense variants. Gene score misZ: 2.1558 (below the threshold of 3.09). Trascript score misZ: 3.0986 (above the threshold of 3.09). GenCC associations: The gene is linked to Alzheimer disease 3, familial isolated dilated cardiomyopathy, dilated cardiomyopathy 1U, acne inversa, familial, 3, Pick disease, behavioral variant of frontotemporal dementia, semantic dementia, early-onset autosomal dominant Alzheimer disease, dilated cardiomyopathy.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.967