12-110614137-G-C

Variant summary

Our verdict is Benign. Variant got -18 ACMG points: 0P and 18B. BP4_Moderate BP6_Very_Strong BS1 BS2

The NM_001082538.3(TCTN1):c.-46G>C variant causes a 5 prime UTR change. The variant allele was found at a frequency of 0.000871 in 1,541,176 control chromosomes in the GnomAD database, including 14 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0044 (5 hom., cov: 31)
  • Exomes 𝑓: 0.00049 (9 hom.)
• Consequence: TCTN1 NM_001082538.3 5_prime_UTR
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: 4.02

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]

ACMG classification

Verdict is Benign. Variant got -18 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.42).
• BP6: Variant 12-110614137-G-C is Benign according to our data. Variant chr12-110614137-G-C is described in ClinVar as [Likely_benign]. Clinvar id is 307202.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00435 (663/152352) while in subpopulation AFR AF= 0.0153 (635/41588). AF 95% confidence interval is 0.0143. There are 5 homozygotes in gnomad4. There are 291 alleles in male gnomad4 subpopulation. Median coverage is 31. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd at 5 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TCTN1	NM_001082538.3	c.-46G>C		5_prime_UTR_variant	1/15	ENST00000397659.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TCTN1	ENST00000397659.9	c.-46G>C		5_prime_UTR_variant	1/15	1	NM_001082538.3	A1

Frequencies

GnomAD3 genomes AF: 0.00436 AC: 663 AN: 152234 Hom.: 5 Cov.: 31

Gnomad AFR AF: 0.0153

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00124

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00316

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00239

GnomAD3 exomes AF: 0.000938 AC: 129 AN: 137578 Hom.: 1 AF XY: 0.000800 AC XY: 60 AN XY: 74960

Gnomad AFR exome AF: 0.0155

Gnomad AMR exome AF: 0.000903

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000599

Gnomad OTH exome AF: 0.000487

GnomAD4 exome AF: 0.000490 AC: 680 AN: 1388824 Hom.: 9 Cov.: 31 AF XY: 0.000444 AC XY: 304 AN XY: 684612

Gnomad4 AFR exome AF: 0.0179

Gnomad4 AMR exome AF: 0.00110

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000269

Gnomad4 OTH exome AF: 0.000764

GnomAD4 genome AF: 0.00435 AC: 663 AN: 152352 Hom.: 5 Cov.: 31 AF XY: 0.00391 AC XY: 291 AN XY: 74508

Gnomad4 AFR AF: 0.0153

Gnomad4 AMR AF: 0.00124

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.00236

Alfa AF: 0.000258 Hom.: 0

Bravo AF: 0.00492

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Dec 08, 2017

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Joubert syndrome 13 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.42
Cadd	Benign	21
Dann	Benign	0.76

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs538932401; hg19: chr12-111051942;