16-81377309-T-C

Variant names:

• chr16-81377309-T-C
• rs141592516
• NM_022041.4:c.1593T>C

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_022041.4(GAN):​c.1593T>C​(p.Val531Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000691 in 1,447,746 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. V531V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: GAN NM_022041.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.0370
• 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: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.7).
• BP7: Synonymous conserved (PhyloP=0.037 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_022041.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAN	NM_022041.4	MANE Select	c.1593T>C	p.Val531Val	synonymous	Exon 10 of 11	NP_071324.1
	GAN	NM_001377486.1		c.954T>C	p.Val318Val	synonymous	Exon 9 of 10	NP_001364415.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAN	ENST00000648994.2	MANE Select	c.1593T>C	p.Val531Val	synonymous	Exon 10 of 11	ENSP00000497351.1
	GAN	ENST00000718305.1		c.1593T>C	p.Val531Val	synonymous	Exon 10 of 11	ENSP00000520738.1
	GAN	ENST00000648349.3		n.*1301T>C		non_coding_transcript_exon	Exon 9 of 10	ENSP00000498114.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.91e-7 AC: 1 AN: 1447746 Hom.: 0 Cov.: 26 AF XY: 0.00 AC XY: 0 AN XY: 721302

⚠️ 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: 33210

American (AMR) AF: 0.0000224 AC: 1 AN: 44698

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26016

East Asian (EAS) AF: 0.00 AC: 0 AN: 39618

South Asian (SAS) AF: 0.00 AC: 0 AN: 85978

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

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5734

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1099184

Other (OTH) AF: 0.00 AC: 0 AN: 59894

⚠️ 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.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.70
CADD	Benign	1.6
DANN	Benign	0.68
PhyloP100		0.037

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: rs141592516; hg19: chr16-81410914;