10-95664117-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_015631.6(TCTN3):c.1774C>T(p.Leu592Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L592V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: TCTN3 NM_015631.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.147

Genes affected

TCTN3 (HGNC:24519): (tectonic family member 3) This gene encodes a member of the tectonic gene family which functions in Hedgehog signal transduction and development of the neural tube. Mutations in this gene have been associated with Orofaciodigital Syndrome IV and Joubert Syndrom 18. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Sep 2012]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.062289655).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TCTN3	NM_015631.6	c.1774C>T	p.Leu592Phe	missense_variant	14/14	ENST00000371217.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TCTN3	ENST00000371217.10	c.1774C>T	p.Leu592Phe	missense_variant	14/14	1	NM_015631.6	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461894 Hom.: 0 Cov.: 31 AF XY: 0.00000963 AC XY: 7 AN XY: 727248

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000927

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Orofacial-digital syndrome IV;C3553758:Joubert syndrome 18 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 25, 2022

Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0". The phenylalanine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 592 of the TCTN3 protein (p.Leu592Phe). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TCTN3-related conditions. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.069
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.47
Cadd	Benign	13
Dann	Uncertain	1.0
DEOGEN2	Benign	0.011	T;T;.;.
Eigen	Benign	-0.98
Eigen_PC	Benign	-1.0
FATHMM_MKL	Benign	0.11	N
LIST_S2	Benign	0.52	T;.;T;T
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.062	T;T;T;T
MetaSVM	Benign	-0.87	T
MutationAssessor	Benign	1.4	L;L;.;.
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Benign	0.29	T
Sift4G	Benign	0.15	T;T;T;T
Polyphen		0.0010	B;B;.;.
Vest4		0.070
MutPred		0.26		Gain of catalytic residue at P590 (P = 0.1451);Gain of catalytic residue at P590 (P = 0.1451);.;.;
MVP		0.16
MPC		0.34
ClinPred		0.17	T
GERP RS		-0.92
Varity_R		0.035
gMVP		0.47

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr10-97423874; COSMIC: COSV104556801;