chr7-77330281-G-A

Variant names:

• chr7-77330281-G-A
• rs147426390
• NM_017439.4:c.1632C>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_017439.4(GSAP):​c.1632C>T​(p.Asn544Asn) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,366 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 0.000013 (0 hom., cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GSAP NM_017439.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.34
• Publications: 0 publications found

Genes affected

GSAP (HGNC:28042): (gamma-secretase activating protein) Accumulation of neurotoxic amyloid-beta is a major hallmark of Alzheimer disease (AD; MIM 104300). Formation of amyloid-beta is catalyzed by gamma-secretase (see PSEN1; MIM 104311), a protease with numerous substrates. PION, or GSAP, selectively increases amyloid-beta production through a mechanism involving its interaction with both gamma-secretase and its substrate, the amyloid-beta precursor protein (APP; MIM 104760) C-terminal fragment (APP-CTF) (He et al., 2010 [PubMed 20811458]).[supplied by OMIM, Nov 2010]

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_017439.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GSAP	NM_017439.4	MANE Select	c.1632C>T	p.Asn544Asn	synonymous	Exon 20 of 31	NP_059135.2	A4D1B5-1
	GSAP	NM_001350896.2		c.1632C>T	p.Asn544Asn	synonymous	Exon 19 of 30	NP_001337825.1
	GSAP	NM_001350897.2		c.1578C>T	p.Asn526Asn	synonymous	Exon 19 of 30	NP_001337826.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GSAP	ENST00000257626.12	TSL:1 MANE Select	c.1632C>T	p.Asn544Asn	synonymous	Exon 20 of 31	ENSP00000257626.7	A4D1B5-1
	GSAP	ENST00000943097.1		c.1686C>T	p.Asn562Asn	synonymous	Exon 20 of 30	ENSP00000613156.1
	GSAP	ENST00000880888.1		c.1632C>T	p.Asn544Asn	synonymous	Exon 20 of 30	ENSP00000550947.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152152 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 250964 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461214 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726928

⚠️ 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: 33464

American (AMR) AF: 0.00 AC: 0 AN: 44694

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86200

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53410

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111486

Other (OTH) AF: 0.00 AC: 0 AN: 60376

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152152 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74312

African (AFR) AF: 0.00 AC: 0 AN: 41444

American (AMR) AF: 0.00 AC: 0 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10592

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000294 AC: 2 AN: 68036

Other (OTH) AF: 0.00 AC: 0 AN: 2086

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.51
CADD	Benign	6.7
DANN	Benign	0.77
PhyloP100		3.3
PromoterAI		-0.12	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.41		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.41		Position offset: -42

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

Other links and lift over

dbSNP: rs147426390; hg19: chr7-76959598;