Submissions for variant NM_001082538.3(TCTN1):c.699TAA[1] (p.Asn235del)

dbSNP: rs797046038

Total submissions: 7

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Genetic Services Laboratory, University of Chicago	RCV000193784	SCV000249138	likely benign	not specified	2021-02-08	criteria provided, single submitter	clinical testing
Invitae	RCV001088798	SCV000562433	likely benign	Familial aplasia of the vermis; Meckel-Gruber syndrome	2024-01-29	criteria provided, single submitter	clinical testing
GeneDx	RCV000726711	SCV000577323	uncertain significance	not provided	2018-09-04	criteria provided, single submitter	clinical testing	A variant of uncertain significance has been identified in the TCTN1 gene. The c.702_704delTAA variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The c.702_704delTAA variant is observed in 168/66,738 (0.3%) alleles from individuals of European background (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The c.702_704delTAA results in an in-frame deletion of a single Asparagine residue, denoted p.Asn235del. Based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant.
Eurofins Ntd Llc (ga)	RCV000726711	SCV000702323	uncertain significance	not provided	2016-10-21	criteria provided, single submitter	clinical testing
Ambry Genetics	RCV002517143	SCV003696630	likely benign	Inborn genetic diseases	2022-04-19	criteria provided, single submitter	clinical testing	This alteration is classified as likely benign based on a combination of the following: population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.
PreventionGenetics, part of Exact Sciences	RCV003927810	SCV004744690	likely benign	TCTN1-related condition	2022-02-03	criteria provided, single submitter	clinical testing	This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications).
Department of Pathology and Laboratory Medicine, Sinai Health System	RCV000726711	SCV001550005	likely benign	not provided		no assertion criteria provided	clinical testing	The TCTN1 p.Asn235del variant was not identified in the literature nor was it identified in LOVD 3.0. The variant was identified in dbSNP (ID: rs1179582623) and ClinVar (classified as uncertain significance by Genetic Services Laboratory, University of Chicago, EGL Genetic Diagnostics and GeneDx, and as likely benign by Invitae). The variant was identified in control databases in 455 of 280942 chromosomes (2 homozygous) at a frequency of 0.00162 increasing the likelihood this could be a low frequency benign variant (Genome Aggregation Database March 6, 2019, v2.1.1). The variant was observed in the following populations: European (non-Finnish) in 420 of 128690 chromosomes (freq: 0.003264), Other in 7 of 7148 chromosomes (freq: 0.000979), European (Finnish) in 12 of 25030 chromosomes (freq: 0.000479), African in 11 of 24202 chromosomes (freq: 0.000455) and Latino in 5 of 35374 chromosomes (freq: 0.000141), but was not observed in the Ashkenazi Jewish, East Asian, or South Asian populations. This variant is an in-frame deletion resulting in the removal of a asparagine (asn) residue at codon 235; the impact of this alteration on TCTN1 protein function is not known. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time although we would lean towards a more benign role for this variant. This variant is classified as likely benign.