rs362305

Positions:

• chr4-3240433-C-G

Variant summary

Our verdict is Benign. Variant got -12 ACMG points: 0P and 12B. BP4_Strong BA1

The ENST00000355072.11(HTT):​c.*374C>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.141 in 307,298 control chromosomes in the GnomAD database, including 4,285 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 0.17 (3012 hom., cov: 34)
  • Exomes 𝑓: 0.11 (1273 hom.)
• Consequence: HTT ENST00000355072.11 3_prime_UTR
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.240

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]

ACMG classification

Verdict is Benign. Variant got -12 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.77).
• BA1: GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.333 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HTT	NM_001388492.1	c.*374C>G		3_prime_UTR_variant	67/67	ENST00000355072.11	NP_001375421.1
HTT	NM_002111.8	c.*374C>G		3_prime_UTR_variant	67/67		NP_002102.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HTT	ENST00000355072.11	c.*374C>G		3_prime_UTR_variant	67/67	1	NM_001388492.1	ENSP00000347184	P2

Frequencies

GnomAD3 genomes AF: 0.168 AC: 25554 AN: 152182 Hom.: 3003 Cov.: 34

Gnomad AFR AF: 0.337

Gnomad AMI AF: 0.0822

Gnomad AMR AF: 0.102

Gnomad ASJ AF: 0.152

Gnomad EAS AF: 0.00577

Gnomad SAS AF: 0.103

Gnomad FIN AF: 0.110

Gnomad MID AF: 0.206

Gnomad NFE AF: 0.108

Gnomad OTH AF: 0.150

GnomAD4 exome AF: 0.114 AC: 17595 AN: 154998 Hom.: 1273 Cov.: 0 AF XY: 0.111 AC XY: 9238 AN XY: 82878

Gnomad4 AFR exome AF: 0.355

Gnomad4 AMR exome AF: 0.0915

Gnomad4 ASJ exome AF: 0.160

Gnomad4 EAS exome AF: 0.00632

Gnomad4 SAS exome AF: 0.105

Gnomad4 FIN exome AF: 0.112

Gnomad4 NFE exome AF: 0.109

Gnomad4 OTH exome AF: 0.122

GnomAD4 genome AF: 0.168 AC: 25587 AN: 152300 Hom.: 3012 Cov.: 34 AF XY: 0.165 AC XY: 12284 AN XY: 74482

Gnomad4 AFR AF: 0.337

Gnomad4 AMR AF: 0.102

Gnomad4 ASJ AF: 0.152

Gnomad4 EAS AF: 0.00578

Gnomad4 SAS AF: 0.103

Gnomad4 FIN AF: 0.110

Gnomad4 NFE AF: 0.108

Gnomad4 OTH AF: 0.148

Alfa AF: 0.147 Hom.: 276

Bravo AF: 0.174

Asia WGS AF: 0.0700 AC: 241 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.77
CADD	Benign	6.7
DANN	Benign	0.75

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

Other links and lift over

dbSNP: rs362305; hg19: chr4-3242160;