21-25915612-G-T

Variant names:

• chr21-25915612-G-T
• rs214488
• NM_000484.4:c.1688-3650C>A

Variant summary

Our verdict is Benign. The variant received -12 ACMG points: 0P and 12B. BP4_Strong BS1 BS2

The NM_000484.4(APP):​c.1688-3650C>A variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00143 in 152,206 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.0014 (1 hom., cov: 35)
• Consequence: APP NM_000484.4 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.173
• Publications: 9 publications found

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]

APP Gene-Disease associations (from GenCC):

• Alzheimer disease type 1

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• cerebral amyloid angiopathy, APP-related

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• ABeta amyloidosis, Arctic type

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• ABeta amyloidosis, dutch type

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• ABeta amyloidosis, Iowa type

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• ABeta amyloidosis, Italian type

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• ABetaA21G amyloidosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• ABetaL34V amyloidosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• early-onset autosomal dominant Alzheimer disease

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Benign. The variant received -12 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.88).
• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00143 (218/152206) while in subpopulation AFR AF = 0.00489 (203/41488). AF 95% confidence interval is 0.00434. There are 1 homozygotes in GnomAd4. There are 103 alleles in the male GnomAd4 subpopulation. Median coverage is 35. This position passed quality control check.
• BS2: High AC in GnomAd4 at 218 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
APP	NM_000484.4	c.1688-3650C>A		intron_variant	Intron 13 of 17	ENST00000346798.8	NP_000475.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
APP	ENST00000346798.8	c.1688-3650C>A		intron_variant	Intron 13 of 17	1	NM_000484.4	ENSP00000284981.4

Frequencies

GnomAD3 genomes AF: 0.00143 AC: 217 AN: 152088 Hom.: 1 Cov.: 35

Gnomad AFR AF: 0.00488

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000851

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.000478

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome AF: 0.00143 AC: 218 AN: 152206 Hom.: 1 Cov.: 35 AF XY: 0.00138 AC XY: 103 AN XY: 74432

African (AFR) AF: 0.00489 AC: 203 AN: 41488

American (AMR) AF: 0.000850 AC: 13 AN: 15302

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5170

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10610

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68022

Other (OTH) AF: 0.000473 AC: 1 AN: 2112

Alfa AF: 0.00 Hom.: 132207

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.88
CADD	Benign	1.4
DANN	Benign	0.37
PhyloP100		0.17

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

Other links and lift over

dbSNP: rs214488; hg19: chr21-27287924;