12-110614164-C-G

Variant names:

• chr12-110614164-C-G
• rs773061089
• NM_001082538.3:c.-19C>G

Variant summary

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

The NM_001082538.3(TCTN1):​c.-19C>G variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,254 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: TCTN1 NM_001082538.3 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.521
• Publications: 0 publications found

Genes affected

TCTN1 (HGNC:26113): (tectonic family member 1) This gene encodes a member of a family of secreted and transmembrane proteins. The orthologous gene in mouse functions downstream of smoothened and rab23 to modulate hedgehog signal transduction. This protein is a component of the tectonic-like complex, which forms a barrier between the ciliary axoneme and the basal body. A mutation in this gene was found in a family with Joubert syndrome-13. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2016]

TCTN1 Gene-Disease associations (from GenCC):

• Joubert syndrome 13

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, 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=-0.79).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001082538.3. 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
	TCTN1	NM_001082538.3	MANE Select	c.-19C>G		5_prime_UTR_premature_start_codon_gain	Exon 1 of 15	NP_001076007.1	Q2MV58-2
	TCTN1	NM_001082538.3	MANE Select	c.-19C>G		5_prime_UTR	Exon 1 of 15	NP_001076007.1	Q2MV58-2
	TCTN1	NM_001082537.3		c.-19C>G		5_prime_UTR_premature_start_codon_gain	Exon 1 of 15	NP_001076006.1	Q2MV58-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TCTN1	ENST00000397659.9	TSL:1 MANE Select	c.-19C>G		5_prime_UTR_premature_start_codon_gain	Exon 1 of 15	ENSP00000380779.4	Q2MV58-2
	TCTN1	ENST00000551590.5	TSL:1	c.-19C>G		5_prime_UTR_premature_start_codon_gain	Exon 1 of 15	ENSP00000448735.1	Q2MV58-1
	TCTN1	ENST00000397655.7	TSL:1	c.-19C>G		5_prime_UTR_premature_start_codon_gain	Exon 1 of 15	ENSP00000380775.3	Q2MV58-3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152254 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

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152254 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74392

⚠️ 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: 41466

American (AMR) AF: 0.00 AC: 0 AN: 15290

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5200

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10630

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

⚠️ 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: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.79
CADD	Benign	5.8
DANN	Benign	0.41
PhyloP100		-0.52
PromoterAI		-0.0027	Neutral

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

Other links and lift over

dbSNP: rs773061089; hg19: chr12-111051969;