chr6-16306563-G-C

Variant names:

• chr6-16306563-G-C
• rs377559897
• NM_001128164.2:c.2214C>G

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_Strong BP7 BS2

The NM_001128164.2(ATXN1):​c.2214C>G​(p.Leu738Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000737 in 1,614,100 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. Synonymous variant affecting the same amino acid position (i.e. L738L) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000072 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000074 (0 hom.)
• Consequence: ATXN1 NM_001128164.2 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.477
• Publications: 1 publications found

Genes affected

ATXN1 (HGNC:10548): (ataxin 1) The autosomal dominant cerebellar ataxias (ADCA) are a heterogeneous group of neurodegenerative disorders characterized by progressive degeneration of the cerebellum, brain stem and spinal cord. Clinically, ADCA has been divided into three groups: ADCA types I-III. ADCAI is genetically heterogeneous, with five genetic loci, designated spinocerebellar ataxia (SCA) 1, 2, 3, 4 and 6, being assigned to five different chromosomes. ADCAII, which always presents with retinal degeneration (SCA7), and ADCAIII often referred to as the `pure' cerebellar syndrome (SCA5), are most likely homogeneous disorders. Several SCA genes have been cloned and shown to contain CAG repeats in their coding regions. ADCA is caused by the expansion of the CAG repeats, producing an elongated polyglutamine tract in the corresponding protein. The expanded repeats are variable in size and unstable, usually increasing in size when transmitted to successive generations. The function of the ataxins is not known. This locus has been mapped to chromosome 6, and it has been determined that the diseased allele contains 40-83 CAG repeats, compared to 6-39 in the normal allele, and is associated with spinocerebellar ataxia type 1 (SCA1). Alternative splicing results in multiple transcript variants, with one variant encoding multiple distinct proteins, ATXN1 and Alt-ATXN1, due to the use of overlapping alternate reading frames. [provided by RefSeq, Nov 2017]

ATXN1 Gene-Disease associations (from GenCC):

• spinocerebellar ataxia type 1

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Benign. The variant received -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).
• BP7: Synonymous conserved (PhyloP=0.477 with no splicing effect.
• BS2: High AC in GnomAd4 at 11 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ATXN1	NM_001128164.2	c.2214C>G	p.Leu738Leu	synonymous_variant	Exon 8 of 8	ENST00000436367.6	NP_001121636.1
ATXN1	NM_000332.4	c.2214C>G	p.Leu738Leu	synonymous_variant	Exon 9 of 9		NP_000323.2
ATXN1	NM_001357857.2	c.*1627C>G		3_prime_UTR_variant	Exon 9 of 9		NP_001344786.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ATXN1	ENST00000436367.6	c.2214C>G	p.Leu738Leu	synonymous_variant	Exon 8 of 8	1	NM_001128164.2	ENSP00000416360.1
ATXN1	ENST00000244769.8	c.2214C>G	p.Leu738Leu	synonymous_variant	Exon 9 of 9	1		ENSP00000244769.3

Frequencies

GnomAD3 genomes AF: 0.0000723 AC: 11 AN: 152212 Hom.: 0 Cov.: 33

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: 0.000162

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000875 AC: 22 AN: 251448 AF XY: 0.000103

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000167

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000739 AC: 108 AN: 1461888 Hom.: 0 Cov.: 32 AF XY: 0.0000743 AC XY: 54 AN XY: 727242

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000464 AC: 4 AN: 86256

European-Finnish (FIN) AF: 0.0000562 AC: 3 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000836 AC: 93 AN: 1112012

Other (OTH) AF: 0.000116 AC: 7 AN: 60396

GnomAD4 genome AF: 0.0000723 AC: 11 AN: 152212 Hom.: 0 Cov.: 33 AF XY: 0.0000538 AC XY: 4 AN XY: 74354

African (AFR) AF: 0.00 AC: 0 AN: 41450

American (AMR) AF: 0.00 AC: 0 AN: 15288

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5196

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

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

European-Non Finnish (NFE) AF: 0.000162 AC: 11 AN: 68042

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000559 Hom.: 0

Bravo AF: 0.000106

EpiCase AF: 0.000218

EpiControl AF: 0.000237

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	5.2
DANN	Benign	0.60
PhyloP100		0.48
Mutation Taster		=100/0	polymorphism

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: rs377559897; hg19: chr6-16306794; COSMIC: COSV55216681;