3-94003764-GG-AA

Variant names:

• chr3-94003764-GG-AA
• NM_001174150.2:c.236_237delGGinsAA
• ARL13B p.Arg79Gln

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PS1 PM5 PP3

The NM_001174150.2(ARL13B):​c.236_237delGGinsAA​(p.Arg79Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R79W) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ARL13B NM_001174150.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.97
• 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: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PS1: Transcript NM_001174150.2 (ARL13B) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-94003763-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 4753888.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

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.236_237delGGinsAA	p.Arg79Gln	missense	N/A	NP_001167621.1	Q3SXY8-1
	ARL13B	NM_182896.3		c.236_237delGGinsAA	p.Arg79Gln	missense	N/A	NP_878899.1	Q3SXY8-1
	ARL13B	NM_001321328.2		c.191_192delGGinsAA	p.Arg64Gln	missense	N/A	NP_001308257.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ARL13B	ENST00000394222.8	TSL:1 MANE Select	c.236_237delGGinsAA	p.Arg79Gln	missense	N/A	ENSP00000377769.3	Q3SXY8-1
	ARL13B	ENST00000471138.5	TSL:1	c.236_237delGGinsAA	p.Arg79Gln	missense	N/A	ENSP00000420780.1	Q3SXY8-1
	ARL13B	ENST00000535334.5	TSL:1	c.-74_-73delGGinsAA		5_prime_UTR	Exon 2 of 9	ENSP00000445145.1	Q3SXY8-3

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		10

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr3-93722608;