rs760376471

Variant names:

• chr12-123687002-C-T
• rs760376471
• NM_024809.5:c.731C>T

Variant summary

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

The NM_024809.5(TCTN2):​c.731C>T​(p.Thr244Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,614,086 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000016 (0 hom.)
• Consequence: TCTN2 NM_024809.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.94
• 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, G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• Joubert syndrome

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

  Inheritance: AR Classification: SUPPORTIVE Submitted by: 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 (MetaRNN=0.42006394).

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.731C>T	p.Thr244Ile	missense	Exon 6 of 18	NP_079085.2
	TCTN2	NM_001143850.3		c.728C>T	p.Thr243Ile	missense	Exon 6 of 18	NP_001137322.1
	TCTN2	NM_001410989.1		c.731C>T	p.Thr244Ile	missense	Exon 6 of 17	NP_001397918.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TCTN2	ENST00000303372.7	TSL:1 MANE Select	c.731C>T	p.Thr244Ile	missense	Exon 6 of 18	ENSP00000304941.5
	TCTN2	ENST00000426174.6	TSL:2	c.728C>T	p.Thr243Ile	missense	Exon 6 of 18	ENSP00000395171.2
	TCTN2	ENST00000965363.1		c.731C>T	p.Thr244Ile	missense	Exon 6 of 17	ENSP00000635422.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152194 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000795 AC: 2 AN: 251482 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000157 AC: 23 AN: 1461892 Hom.: 0 Cov.: 33 AF XY: 0.0000193 AC XY: 14 AN XY: 727246

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 0.0000189 AC: 21 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152194 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74350

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41460

American (AMR) AF: 0.0000655 AC: 1 AN: 15264

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

South Asian (SAS) AF: 0.00 AC: 0 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68048

Other (OTH) AF: 0.00 AC: 0 AN: 2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.0000282 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Inborn genetic diseases (1)
-	1	-	Meckel-Gruber syndrome;C0431399:Joubert syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.42
BayesDel_addAF	Benign	-0.079	T
BayesDel_noAF	Benign	-0.34
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.63	D
Eigen	Uncertain	0.41
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Benign	0.84	T
M_CAP	Benign	0.043	D
MetaRNN	Benign	0.42	T
MetaSVM	Benign	-0.32	T
MutationAssessor	Benign	1.2	L
PhyloP100		2.9
PrimateAI	Benign	0.37	T
PROVEAN	Uncertain	-3.4	D
REVEL	Benign	0.24
Sift	Uncertain	0.010	D
Sift4G	Uncertain	0.010	D
Polyphen		0.90	P
Vest4		0.38
MutPred		0.46		Gain of catalytic residue at Y249 (P = 8e-04)
MVP		0.94
MPC		0.49
ClinPred		0.90	D
GERP RS		5.0
Varity_R		0.19
gMVP		0.65
Mutation Taster		=81/19	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs760376471; hg19: chr12-124171549;