chr21-25881476-T-G

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_StrongBS1_SupportingBS2

The NM_000484.4(APP):​c.*194A>C variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000304 in 660,646 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.00018 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00034 ( 0 hom. )

Consequence

APP
NM_000484.4 3_prime_UTR

Scores

2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -0.971
Variant links:
Genes affected
APP (HGNC:620): (amyloid beta precursor protein) This gene encodes a cell surface receptor and transmembrane precursor protein that is cleaved by secretases to form a number of peptides. Some of these peptides are secreted and can bind to the acetyltransferase complex APBB1/TIP60 to promote transcriptional activation, while others form the protein basis of the amyloid plaques found in the brains of patients with Alzheimer disease. In addition, two of the peptides are antimicrobial peptides, having been shown to have bacteriocidal and antifungal activities. Mutations in this gene have been implicated in autosomal dominant Alzheimer disease and cerebroarterial amyloidosis (cerebral amyloid angiopathy). Multiple transcript variants encoding several different isoforms have been found for this gene. [provided by RefSeq, Aug 2014]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -9 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.51).
BS1
Variant frequency is greater than expected in population eas. gnomad4_exome allele frequency = 0.000342 (174/508436) while in subpopulation EAS AF= 0.00355 (111/31298). AF 95% confidence interval is 0.00301. There are 0 homozygotes in gnomad4_exome. There are 92 alleles in male gnomad4_exome subpopulation. Median coverage is 5. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
BS2
High AC in GnomAd4 at 27 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
APPNM_000484.4 linkuse as main transcriptc.*194A>C 3_prime_UTR_variant 18/18 ENST00000346798.8

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
APPENST00000346798.8 linkuse as main transcriptc.*194A>C 3_prime_UTR_variant 18/181 NM_000484.4 P05067-1

Frequencies

GnomAD3 genomes
AF:
0.000177
AC:
27
AN:
152210
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000338
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000196
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000192
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000132
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.000342
AC:
174
AN:
508436
Hom.:
0
Cov.:
5
AF XY:
0.000339
AC XY:
92
AN XY:
271210
show subpopulations
Gnomad4 AFR exome
AF:
0.000210
Gnomad4 AMR exome
AF:
0.0000706
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00355
Gnomad4 SAS exome
AF:
0.000190
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.000132
Gnomad4 OTH exome
AF:
0.000282
GnomAD4 genome
AF:
0.000177
AC:
27
AN:
152210
Hom.:
0
Cov.:
32
AF XY:
0.000175
AC XY:
13
AN XY:
74362
show subpopulations
Gnomad4 AFR
AF:
0.000338
Gnomad4 AMR
AF:
0.000196
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.000192
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000132
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000214
Hom.:
0
Bravo
AF:
0.000132
Asia WGS
AF:
0.000577
AC:
2
AN:
3478

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Alzheimer disease Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 12, 2018This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.51
CADD
Benign
14
DANN
Benign
0.83

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs199977643; hg19: chr21-27253787; API