rs987899301

Variant names:

• chr12-123686959-G-A
• rs987899301
• NM_024809.5:c.688G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_024809.5(TCTN2):​c.688G>A​(p.Asp230Asn) variant causes a missense change. The variant allele was found at a frequency of 0.0000149 in 1,614,032 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. D230D) has been classified as Likely benign.

• 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: 5.62
• 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: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

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.688G>A	p.Asp230Asn	missense	Exon 6 of 18	NP_079085.2
	TCTN2	NM_001143850.3		c.685G>A	p.Asp229Asn	missense	Exon 6 of 18	NP_001137322.1	Q96GX1-2
	TCTN2	NM_001410989.1		c.688G>A	p.Asp230Asn	missense	Exon 6 of 17	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.688G>A	p.Asp230Asn	missense	Exon 6 of 18	ENSP00000304941.5	Q96GX1-1
	TCTN2	ENST00000426174.6	TSL:2	c.685G>A	p.Asp229Asn	missense	Exon 6 of 18	ENSP00000395171.2	Q96GX1-2
	TCTN2	ENST00000965363.1		c.688G>A	p.Asp230Asn	missense	Exon 6 of 17	ENSP00000635422.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152140 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000795 AC: 2 AN: 251486 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: 0.0000151 AC XY: 11 AN XY: 727246

African (AFR) AF: 0.00 AC: 0 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: 0.00 AC: 0 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: 0.0000331 AC: 2 AN: 60394

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152140 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74300

African (AFR) AF: 0.00 AC: 0 AN: 41436

American (AMR) AF: 0.00 AC: 0 AN: 15256

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5184

South Asian (SAS) AF: 0.00 AC: 0 AN: 4818

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68040

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.0000302

EpiCase AF: 0.000109

EpiControl AF: 0.00

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Inborn genetic diseases (1)
-	1	-	Meckel-Gruber syndrome;C5979921:Joubert syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.46
CADD	Benign	19
DANN	Uncertain	0.99
DEOGEN2	Benign	0.40	T
Eigen	Benign	-0.34
Eigen_PC	Benign	-0.34
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Benign	0.64	T
M_CAP	Uncertain	0.18	D
MetaRNN	Uncertain	0.44	T
MetaSVM	Benign	-0.53	T
MutationAssessor	Benign	1.9	L
PhyloP100		5.6
PrimateAI	Benign	0.36	T
PROVEAN	Uncertain	-2.8	D
REVEL	Uncertain	0.36
Sift	Benign	0.10	T
Sift4G	Uncertain	0.050	T
Polyphen		0.30	B
Vest4		0.22
MVP		0.78
MPC		0.32
ClinPred		0.36	T
GERP RS		4.1
Varity_R		0.070
gMVP		0.74
Mutation Taster		=83/17	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs987899301; hg19: chr12-124171506;