3-124446759-A-C

Variant names:

• chr3-124446759-A-C
• rs77701768
• NM_001388419.1:c.3430-4A>C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001388419.1(KALRN):​c.3430-4A>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 2/2 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KALRN NM_001388419.1 splice_region, intron
• Scores: Splicing: ADA: 0.00009608
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.394

Genes affected

KALRN (HGNC:4814): (kalirin RhoGEF kinase) Huntington's disease (HD), a neurodegenerative disorder characterized by loss of striatal neurons, is caused by an expansion of a polyglutamine tract in the HD protein huntingtin. This gene encodes a protein that interacts with the huntingtin-associated protein 1, which is a huntingtin binding protein that may function in vesicle trafficking. [provided by RefSeq, Apr 2016]

ACMG classification

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 (BayesDel_noAF=-0.78).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KALRN	NM_001388419.1	c.3430-4A>C		splice_region_variant, intron_variant	Intron 20 of 59	ENST00000682506.1	NP_001375348.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KALRN	ENST00000682506.1	c.3430-4A>C		splice_region_variant, intron_variant	Intron 20 of 59		NM_001388419.1	ENSP00000508359.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.78
CADD	Benign	6.5
DANN	Benign	0.67

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000096
dbscSNV1_RF	Benign	0.0

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

Publications

LitVar

Other links and lift over

dbSNP: rs77701768; hg19: chr3-124165606;