NM_001388492.1:c.8457-379T>C

Variant names:

• chr4-3234905-T-C
• rs2530596
• NM_001388492.1:c.8457-379T>C

Variant summary

Our verdict is Benign. The variant received -12 ACMG points: 0P and 12B. BP4_Strong BA1

The NM_001388492.1(HTT):​c.8457-379T>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.333 in 152,020 control chromosomes in the GnomAD database, including 10,074 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 0.33 (10074 hom., cov: 32)
• Consequence: HTT NM_001388492.1 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -2.40
• Publications: 2 publications found

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 Gene-Disease associations (from GenCC):

• Huntington disease

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), Orphanet
• Lopes-Maciel-Rodan syndrome

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• juvenile Huntington 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=-0.91).
• BA1: GnomAd4 highest subpopulation (EAS) allele frequency at 95% confidence interval = 0.427 is higher than 0.05.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001388492.1. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HTT	NM_001388492.1	MANE Select	c.8457-379T>C		intron	N/A	NP_001375421.1
	HTT	NM_002111.8		c.8457-379T>C		intron	N/A	NP_002102.4

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HTT	ENST00000355072.11	TSL:1 MANE Select	c.8457-379T>C		intron	N/A	ENSP00000347184.5
	HTT	ENST00000510626.5	TSL:1	n.9585-379T>C		intron	N/A
	HTT	ENST00000681528.1		c.8289-379T>C		intron	N/A	ENSP00000506116.1

Frequencies

GnomAD3 genomes AF: 0.333 AC: 50619 AN: 151902 Hom.: 10070 Cov.: 32

Gnomad AFR AF: 0.110

Gnomad AMI AF: 0.402

Gnomad AMR AF: 0.356

Gnomad ASJ AF: 0.451

Gnomad EAS AF: 0.443

Gnomad SAS AF: 0.325

Gnomad FIN AF: 0.468

Gnomad MID AF: 0.266

Gnomad NFE AF: 0.429

Gnomad OTH AF: 0.329

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

GnomAD4 genome AF: 0.333 AC: 50624 AN: 152020 Hom.: 10074 Cov.: 32 AF XY: 0.332 AC XY: 24661 AN XY: 74288

African (AFR) AF: 0.110 AC: 4556 AN: 41488

American (AMR) AF: 0.356 AC: 5442 AN: 15288

Ashkenazi Jewish (ASJ) AF: 0.451 AC: 1566 AN: 3470

East Asian (EAS) AF: 0.442 AC: 2280 AN: 5158

South Asian (SAS) AF: 0.324 AC: 1554 AN: 4800

European-Finnish (FIN) AF: 0.468 AC: 4937 AN: 10560

Middle Eastern (MID) AF: 0.276 AC: 81 AN: 294

European-Non Finnish (NFE) AF: 0.429 AC: 29135 AN: 67946

Other (OTH) AF: 0.336 AC: 707 AN: 2106

Alfa AF: 0.284 Hom.: 2946

Bravo AF: 0.318

Asia WGS AF: 0.374 AC: 1300 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.91
CADD	Benign	0.92
DANN	Benign	0.54
PhyloP100		-2.4
Mutation Taster		=100/0	polymorphism (auto)

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: rs2530596; hg19: chr4-3236632;