6-121090851-A-C

Variant names:

• chr6-121090851-A-C
• NM_152730.6:c.3654+2T>G

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_152730.6(TBC1D32):​c.3654+2T>G variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TBC1D32 NM_152730.6 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.76
• Publications: 0 publications found

Genes affected

TBC1D32 (HGNC:21485): (TBC1 domain family member 32) This gene encodes a TBC-domain containing protein. Studies of a similar protein in mouse and zebrafish suggest that the encoded protein is involved in sonic hedgehog signaling, and that it interacts with and stabilizes cell cycle-related kinase. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2014]

TBC1D32 Gene-Disease associations (from GenCC):

• ciliopathy

  Inheritance: AR Classification: DEFINITIVE, MODERATE Submitted by: Illumina, G2P
• orofaciodigital syndrome

  Inheritance: AR Classification: MODERATE Submitted by: Franklin by Genoox
• orofaciodigital syndrome IX

  Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.05007949 fraction of the gene. Cryptic splice site detected, with MaxEntScore 7, offset of 4, new splice context is: gaaGTatgt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TBC1D32	NM_152730.6	c.3654+2T>G		splice_donor_variant, intron_variant	Intron 31 of 31	ENST00000398212.7	NP_689943.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TBC1D32	ENST00000398212.7	c.3654+2T>G		splice_donor_variant, intron_variant	Intron 31 of 31	5	NM_152730.6	ENSP00000381270.2
TBC1D32	ENST00000275159.11	c.3777+2T>G		splice_donor_variant, intron_variant	Intron 32 of 32	5		ENSP00000275159.6
TBC1D32	ENST00000464622.5	n.*4294+2T>G		splice_donor_variant, intron_variant	Intron 35 of 35	2		ENSP00000428839.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Ciliopathy Uncertain:1

Apr 21, 2023

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: research

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Pathogenic	32
DANN	Uncertain	0.98
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		8.8
GERP RS		4.0
Mutation Taster		=1/99	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.92
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: 2

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

Other links and lift over

hg19: chr6-121411997;