12-123671329-A-G

Variant names:

• chr12-123671329-A-G
• rs767155532
• NM_024809.5:c.82+7A>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_024809.5(TCTN2):​c.82+7A>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,152 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TCTN2 NM_024809.5 splice_region, intron
• Scores: Splicing: ADA: 0.0006043
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.762
• Publications: 0 publications found

Genes affected

TCTN2 (HGNC:25774): (tectonic family member 2) This gene encodes a type I membrane protein that belongs to the tectonic family. Studies in mice suggest that this protein may be involved in hedgehog signaling, and essential for ciliogenesis. Mutations in this gene are associated with Meckel syndrome type 8. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2011]

TCTN2 Gene-Disease associations (from GenCC):

• Joubert syndrome 24

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), PanelApp Australia, G2P, Ambry Genetics
• Meckel syndrome, type 8

  Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia
• Joubert syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Meckel syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.8).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_024809.5. 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
	TCTN2	NM_024809.5	MANE Select	c.82+7A>G		splice_region intron	N/A	NP_079085.2
	TCTN2	NM_001143850.3		c.82+7A>G		splice_region intron	N/A	NP_001137322.1	Q96GX1-2
	TCTN2	NM_001410989.1		c.82+7A>G		splice_region intron	N/A	NP_001397918.1	A0A7P0T8X4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TCTN2	ENST00000303372.7	TSL:1 MANE Select	c.82+7A>G		splice_region intron	N/A	ENSP00000304941.5	Q96GX1-1
	TCTN2	ENST00000426174.6	TSL:2	c.82+7A>G		splice_region intron	N/A	ENSP00000395171.2	Q96GX1-2
	TCTN2	ENST00000965363.1		c.82+7A>G		splice_region intron	N/A	ENSP00000635422.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461152 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 726876

African (AFR) AF: 0.00 AC: 0 AN: 33462

American (AMR) AF: 0.00 AC: 0 AN: 44668

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26110

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39686

South Asian (SAS) AF: 0.00 AC: 0 AN: 86214

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53154

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111738

Other (OTH) AF: 0.00 AC: 0 AN: 60354

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.42
BayesDel_noAF	Benign	-0.80
CADD	Benign	4.1
DANN	Benign	0.77
PhyloP100		-0.76
PromoterAI		-0.048	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00060
dbscSNV1_RF	Benign	0.048
SpliceAI score (max)		0.16		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: rs767155532; hg19: chr12-124155876;