3-94039910-C-G

Variant names:

• chr3-94039910-C-G
• rs752196300
• NM_001174150.2:c.720C>G

Variant summary

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

The NM_001174150.2(ARL13B):​c.720C>G​(p.Leu240Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,778 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. L240L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: ARL13B NM_001174150.2 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -1.69
• Publications: 0 publications found

Genes affected

ARL13B (HGNC:25419): (ADP ribosylation factor like GTPase 13B) This gene encodes a member of the ADP-ribosylation factor-like family. The encoded protein is a small GTPase that contains both N-terminal and C-terminal guanine nucleotide-binding motifs. This protein is localized in the cilia and plays a role in cilia formation and in maintenance of cilia. Mutations in this gene are the cause of Joubert syndrome 8. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Mar 2010]

ARL13B Gene-Disease associations (from GenCC):

• Joubert syndrome

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• Joubert syndrome 8

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics

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=-0.87).
• BP7: Synonymous conserved (PhyloP=-1.69 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001174150.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ARL13B	NM_001174150.2	MANE Select	c.720C>G	p.Leu240Leu	synonymous	Exon 6 of 10	NP_001167621.1	Q3SXY8-1
	ARL13B	NM_182896.3		c.720C>G	p.Leu240Leu	synonymous	Exon 6 of 11	NP_878899.1	Q3SXY8-1
	ARL13B	NM_001321328.2		c.675C>G	p.Leu225Leu	synonymous	Exon 7 of 11	NP_001308257.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ARL13B	ENST00000394222.8	TSL:1 MANE Select	c.720C>G	p.Leu240Leu	synonymous	Exon 6 of 10	ENSP00000377769.3	Q3SXY8-1
	ARL13B	ENST00000471138.5	TSL:1	c.720C>G	p.Leu240Leu	synonymous	Exon 6 of 11	ENSP00000420780.1	Q3SXY8-1
	ARL13B	ENST00000535334.5	TSL:1	c.411C>G	p.Leu137Leu	synonymous	Exon 5 of 9	ENSP00000445145.1	Q3SXY8-3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461778 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 727176

⚠️ 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: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39678

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86226

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111976

Other (OTH) AF: 0.00 AC: 0 AN: 60392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00139817), 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	-0.87
CADD	Benign	0.15
DANN	Benign	0.40
PhyloP100		-1.7

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: rs752196300; hg19: chr3-93758754;