dbSNP rs1065747: HTT:p.Ala1115Asp (chr4-3148053-C-A) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_001388492.1(HTT):c.3344C>A(p.Ala1115Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,764 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

HTT
NM_001388492.1 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 1.26

Variant links:

Genes affected

HTT (HGNC:4851): (huntingtin) Huntingtin is a disease gene linked to Huntington's disease, a neurodegenerative disorder characterized by loss of striatal neurons. This is thought to be caused by an expanded, unstable trinucleotide repeat in the huntingtin gene, which translates as a polyglutamine repeat in the protein product. A fairly broad range of trinucleotide repeats (9-35) has been identified in normal controls, and repeat numbers in excess of 40 have been described as pathological. The huntingtin locus is large, spanning 180 kb and consisting of 67 exons. The huntingtin gene is widely expressed and is required for normal development. It is expressed as 2 alternatively polyadenylated forms displaying different relative abundance in various fetal and adult tissues. The larger transcript is approximately 13.7 kb and is expressed predominantly in adult and fetal brain whereas the smaller transcript of approximately 10.3 kb is more widely expressed. The genetic defect leading to Huntington's disease may not necessarily eliminate transcription, but may confer a new property on the mRNA or alter the function of the protein. One candidate is the huntingtin-associated protein-1, highly expressed in brain, which has increased affinity for huntingtin protein with expanded polyglutamine repeats. This gene contains an upstream open reading frame in the 5' UTR that inhibits expression of the huntingtin gene product through translational repression. [provided by RefSeq, Jul 2016]

HTT links:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.05509901).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HTT	NM_001388492.1 link	c.3344C>A	p.Ala1115Asp	missense_variant	Exon 26 of 67	ENST00000355072.11	NP_001375421.1
HTT	NM_002111.8 link	c.3344C>A	p.Ala1115Asp	missense_variant	Exon 26 of 67		NP_002102.4	P42858

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HTT	ENST00000355072.11 link	c.3344C>A	p.Ala1115Asp	missense_variant	Exon 26 of 67	1	NM_001388492.1	ENSP00000347184.5		P42858

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000401

AC:

AN:

249370

Hom.:

AF XY:

0.00000739

AC XY:

AN XY:

135304

show subpopulations

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 SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461764

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727192

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000348

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.14

BayesDel_addAF

Benign

-0.31

BayesDel_noAF

Benign

-0.59

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Benign

0.14

Eigen

Benign

-0.64

Eigen_PC

Benign

-0.57

FATHMM_MKL

Benign

0.28

LIST_S2

Benign

0.75

M_CAP

Benign

0.015

MetaRNN

Benign

0.055

MetaSVM

Benign

-0.96

MutationAssessor

Benign

1.5

PrimateAI

Benign

0.35

PROVEAN

Benign

-0.55

REVEL

Benign

0.014

Sift

Uncertain

0.017

Sift4G

Uncertain

0.0020

Polyphen

0.21

Vest4

0.31

MutPred

0.17

Loss of glycosylation at P1117 (P = 0.0287);

MVP

0.23

MPC

0.64

ClinPred

0.23

GERP RS

2.6

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.093

gMVP

0.56

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Computational scores

Splicing

Publications

LitVar

Other links and lift over