chr3-63912702-A-G

Variant names:

• chr3-63912702-A-G
• rs772918244
• NM_001377405.1:c.104A>G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001377405.1(ATXN7):​c.104A>G​(p.Gln35Arg) variant causes a missense 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. 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. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q35P) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: ATXN7 NM_001377405.1 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.496

Genes affected

ATXN7 (HGNC:10560): (ataxin 7) 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. This locus has been mapped to chromosome 3, and it has been determined that the diseased allele associated with spinocerebellar ataxia-7 contains 37-306 CAG repeats (near the N-terminus), compared to 4-35 in the normal allele. The encoded protein is a component of the SPT3/TAF9/GCN5 acetyltransferase (STAGA) and TBP-free TAF-containing (TFTC) chromatin remodeling complexes, and it thus plays a role in transcriptional regulation. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2016]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.09314895).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ATXN7	NM_001377405.1	c.104A>G	p.Gln35Arg	missense_variant	Exon 3 of 13	ENST00000674280.1	NP_001364334.1
ATXN7	NM_001177387.1	c.104A>G	p.Gln35Arg	missense_variant	Exon 2 of 13		NP_001170858.1
ATXN7	NM_000333.4	c.104A>G	p.Gln35Arg	missense_variant	Exon 3 of 13		NP_000324.1
ATXN7	NM_001377406.1	c.104A>G	p.Gln35Arg	missense_variant	Exon 2 of 12		NP_001364335.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ATXN7	ENST00000674280.1	c.104A>G	p.Gln35Arg	missense_variant	Exon 3 of 13		NM_001377405.1	ENSP00000501377.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1037690 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 496306

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.50
CADD	Benign	8.8
DANN	Benign	0.51
DEOGEN2	Benign	0.089	.;T;.;T;.
Eigen	Benign	-0.23
Eigen_PC	Benign	-0.29
FATHMM_MKL	Benign	0.40	N
LIST_S2	Benign	0.25	T;T;T;.;.
M_CAP	Benign	0.012	T
MetaRNN	Benign	0.093	T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.34	.;N;N;N;N
PrimateAI	Pathogenic	0.81	D
PROVEAN	Benign	-0.27	.;N;N;N;.
REVEL	Benign	0.10
Sift	Benign	0.88	.;T;T;T;.
Sift4G	Benign	0.44	.;T;T;T;.
Polyphen		0.91, 0.94	.;P;P;P;P
Vest4		0.27, 0.27, 0.28
MutPred		0.15		Gain of MoRF binding (P = 0.0294);Gain of MoRF binding (P = 0.0294);Gain of MoRF binding (P = 0.0294);Gain of MoRF binding (P = 0.0294);Gain of MoRF binding (P = 0.0294);
MVP		0.67
ClinPred		0.14	T
GERP RS		2.8
Varity_R		0.058
gMVP		0.23

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: rs772918244; hg19: chr3-63898378;