16-81354723-C-A

Variant names:

• chr16-81354723-C-A
• rs119485090
• NM_022041.4:c.601C>A

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_022041.4(GAN):​c.601C>A​(p.Arg201Arg) variant causes a synonymous change. The variant allele was found at a frequency of 0.00000069 in 1,449,838 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.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: GAN NM_022041.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.70
• Publications: 0 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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.18).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GAN	NM_022041.4	c.601C>A	p.Arg201Arg	synonymous_variant	Exon 3 of 11	ENST00000648994.2	NP_071324.1
GAN	NM_001377486.1	c.-39C>A		5_prime_UTR_variant	Exon 2 of 10		NP_001364415.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GAN	ENST00000648994.2	c.601C>A	p.Arg201Arg	synonymous_variant	Exon 3 of 11		NM_022041.4	ENSP00000497351.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.90e-7 AC: 1 AN: 1449838 Hom.: 0 Cov.: 28 AF XY: 0.00000138 AC XY: 1 AN XY: 722158

⚠️ 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: 33228

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26052

East Asian (EAS) AF: 0.00 AC: 0 AN: 39636

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 85940

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5746

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1101074

Other (OTH) AF: 0.00 AC: 0 AN: 60036

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.18
CADD	Benign	13
DANN	Benign	0.76
PhyloP100		3.7

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: rs119485090; hg19: chr16-81388328;