16-2496096-C-T

Variant names:

• chr16-2496096-C-T
• rs549380273
• NM_001199107.2:c.-53C>T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_001199107.2(TBC1D24):​c.-53C>T variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,609,250 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000014 (0 hom.)
• Consequence: TBC1D24 NM_001199107.2 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.206
• Publications: 0 publications found

Genes affected

TBC1D24 (HGNC:29203): (TBC1 domain family member 24) This gene encodes a protein with a conserved domain, referred to as the TBC domain, characteristic of proteins which interact with GTPases. TBC domain proteins may serve as GTPase-activating proteins for a particular group of GTPases, the Rab (Ras-related proteins in brain) small GTPases which are involved in the regulation of membrane trafficking. Mutations in this gene are associated with familial infantile myoclonic epilepsy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2011]

TBC1D24 Gene-Disease associations (from GenCC):

• DOORS syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet, PanelApp Australia, G2P
• familial infantile myoclonic epilepsy

  Inheritance: AR Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Orphanet
• autosomal dominant nonsyndromic hearing loss 65

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• autosomal dominant nonsyndromic hearing loss

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• malignant migrating partial seizures of infancy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• focal epilepsy-intellectual disability-cerebro-cerebellar malformation

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• hearing loss, autosomal recessive

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• progressive myoclonic epilepsy with dystonia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• nonsyndromic genetic hearing loss

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• autosomal recessive nonsyndromic hearing loss 86

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

ENSG00000260272 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.78).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TBC1D24	NM_001199107.2	c.-53C>T		5_prime_UTR_variant	Exon 2 of 8	ENST00000646147.1	NP_001186036.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TBC1D24	ENST00000646147.1	c.-53C>T		5_prime_UTR_variant	Exon 2 of 8		NM_001199107.2	ENSP00000494678.1
ENSG00000260272	ENST00000564543.1	c.-53C>T		5_prime_UTR_variant	Exon 1 of 3	2		ENSP00000455547.1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152258 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000384

Gnomad SAS AF: 0.000414

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.0000137 AC: 20 AN: 1456874 Hom.: 0 Cov.: 31 AF XY: 0.0000193 AC XY: 14 AN XY: 724152

African (AFR) AF: 0.00 AC: 0 AN: 33384

American (AMR) AF: 0.00 AC: 0 AN: 44438

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26000

East Asian (EAS) AF: 0.000101 AC: 4 AN: 39614

South Asian (SAS) AF: 0.0000818 AC: 7 AN: 85584

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52638

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5682

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1109390

Other (OTH) AF: 0.000150 AC: 9 AN: 60144

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152376 Hom.: 0 Cov.: 33 AF XY: 0.0000403 AC XY: 3 AN XY: 74514

African (AFR) AF: 0.00 AC: 0 AN: 41592

American (AMR) AF: 0.00 AC: 0 AN: 15306

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

East Asian (EAS) AF: 0.000385 AC: 2 AN: 5192

South Asian (SAS) AF: 0.000414 AC: 2 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68038

Other (OTH) AF: 0.00 AC: 0 AN: 2116

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000189

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Familial infantile myoclonic epilepsy Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.78
CADD	Benign	4.7
DANN	Benign	0.40
PhyloP100		0.21
PromoterAI		0.025	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs549380273; hg19: chr16-2546097;