rs1190709905

chr16-81363917-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_022041.4(GAN):c.1210C>G(p.Gln404Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,050 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. Q404Q) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: GAN NM_022041.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.37

Genes affected

GAN (HGNC:4137): (gigaxonin) This gene encodes a member of the cytoskeletal BTB/kelch (Broad-Complex, Tramtrack and Bric a brac) repeat family. The encoded protein plays a role in neurofilament architecture and is involved in mediating the ubiquitination and degradation of some proteins. Defects in this gene are a cause of giant axonal neuropathy (GAN). [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.834

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GAN	NM_022041.4	c.1210C>G	p.Gln404Glu	missense_variant	7/11	ENST00000648994.2
GAN	NM_001377486.1	c.571C>G	p.Gln191Glu	missense_variant	6/10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GAN	ENST00000648994.2	c.1210C>G	p.Gln404Glu	missense_variant	7/11		NM_022041.4	P1
GAN	ENST00000648349.2	c.*918C>G		3_prime_UTR_variant, NMD_transcript_variant	6/10
GAN	ENST00000650388.1	c.*567C>G		3_prime_UTR_variant, NMD_transcript_variant	5/9

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461050 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726868

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Giant axonal neuropathy 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 11, 2017

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with GAN-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamine with glutamic acid at codon 404 of the GAN protein (p.Gln404Glu). The glutamine residue is moderately conserved and there is a small physicochemical difference between glutamine and glutamic acid. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.16
BayesDel_addAF	Uncertain	0.048	T
BayesDel_noAF	Benign	-0.17
Cadd	Benign	22
Dann	Uncertain	0.99
DEOGEN2	Benign	0.30	T;T
Eigen	Uncertain	0.37
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Benign	0.019	T
MetaRNN	Pathogenic	0.83	D;D
MetaSVM	Benign	-0.31	T
MutationAssessor	Benign	0.72	N;N
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.63	T
Sift4G	Benign	0.13	T;.
Polyphen		0.71	P;P
Vest4		0.72
MutPred		0.75		Loss of MoRF binding (P = 0.0411);Loss of MoRF binding (P = 0.0411);
MVP		0.88
MPC		0.32
ClinPred		0.97	D
GERP RS		5.1
Varity_R		0.76
gMVP		0.81

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: rs1190709905; hg19: chr16-81397522;