rs1252273429

Variant names:

• chr16-81315225-G-A
• rs1252273429
• NM_022041.4:c.112G>A

Your query was ambiguous. Multiple possible variants found:

• chr16-81315225-G-A
• chr16-81315225-G-C
• chr16-81315225-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_022041.4(GAN):​c.112G>A​(p.Gly38Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000699 in 1,431,072 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 (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: GAN NM_022041.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.91
• Publications: 1 publications found

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]

GAN Gene-Disease associations (from GenCC):

• giant axonal neuropathy 1

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 11 curated pathogenic missense variants (we use a threshold of 10). The gene has 3 curated benign missense variants. Trascript score misZ: -2.0288 (below the threshold of 3.09). GenCC associations: The gene is linked to giant axonal neuropathy 1.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.931

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GAN	NM_022041.4	c.112G>A	p.Gly38Arg	missense_variant	Exon 1 of 11	ENST00000648994.2	NP_071324.1
GAN	NM_001377486.1	c.-413G>A		5_prime_UTR_variant	Exon 1 of 10		NP_001364415.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GAN	ENST00000648994.2	c.112G>A	p.Gly38Arg	missense_variant	Exon 1 of 11		NM_022041.4	ENSP00000497351.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.99e-7 AC: 1 AN: 1431072 Hom.: 0 Cov.: 32 AF XY: 0.00000141 AC XY: 1 AN XY: 711206

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 30382

American (AMR) AF: 0.00 AC: 0 AN: 41614

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25220

East Asian (EAS) AF: 0.00 AC: 0 AN: 36574

South Asian (SAS) AF: 0.00 AC: 0 AN: 82132

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51572

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5630

European-Non Finnish (NFE) AF: 9.10e-7 AC: 1 AN: 1098896

Other (OTH) AF: 0.00 AC: 0 AN: 59052

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Giant axonal neuropathy 1 Uncertain:1

Oct 15, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. 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: "Probably 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 glycine with arginine at codon 38 of the GAN protein (p.Gly38Arg). The glycine residue is moderately conserved and there is a moderate physicochemical difference between glycine and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.44
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.060
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.83	D;D
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.92	.;D
M_CAP	Pathogenic	1.0	D
MetaRNN	Pathogenic	0.93	D;D
MetaSVM	Uncertain	0.035	D
MutationAssessor	Uncertain	2.4	M;M
PhyloP100		8.9
PrimateAI	Pathogenic	0.95	D
Sift4G	Benign	0.40	T;.
Polyphen		0.97	D;D
Vest4		0.36
MutPred		0.74		Gain of solvent accessibility (P = 0.0584);Gain of solvent accessibility (P = 0.0584);
MVP		0.87
MPC		0.59
ClinPred		0.98	D
GERP RS		4.2
PromoterAI		0.048	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.81
gMVP		0.76

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: rs1252273429; hg19: chr16-81348830;