16-2496977-G-T

Variant names:

• chr16-2496977-G-T
• rs754019727
• NM_001199107.2:c.829G>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_001199107.2(TBC1D24):​c.829G>T​(p.Ala277Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,610 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A277T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: TBC1D24 NM_001199107.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.38
• Publications: 1 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: Orphanet, Labcorp Genetics (formerly Invitae), G2P, PanelApp Australia, ClinGen, Ambry Genetics
• familial infantile myoclonic epilepsy

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

  Inheritance: AD Classification: STRONG, MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia
• autosomal recessive nonsyndromic hearing loss 86

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: PanelApp Australia, Ambry Genetics
• developmental and epileptic encephalopathy, 16

  Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia
• 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

ENSG00000260272 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 13 uncertain in NM_001199107.2
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.14119425).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001199107.2. 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
	TBC1D24	NM_001199107.2	MANE Select	c.829G>T	p.Ala277Ser	missense	Exon 2 of 8	NP_001186036.1	Q9ULP9-1
	TBC1D24	NM_020705.3		c.829G>T	p.Ala277Ser	missense	Exon 2 of 7	NP_065756.1	Q9ULP9-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TBC1D24	ENST00000646147.1	MANE Select	c.829G>T	p.Ala277Ser	missense	Exon 2 of 8	ENSP00000494678.1	Q9ULP9-1
	TBC1D24	ENST00000567020.7	TSL:1	c.829G>T	p.Ala277Ser	missense	Exon 2 of 7	ENSP00000454408.1	Q9ULP9-2
	ENSG00000260272	ENST00000564543.1	TSL:2	c.829G>T	p.Ala277Ser	missense	Exon 1 of 3	ENSP00000455547.1	H3BQ06

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000160 AC: 4 AN: 249414 AF XY: 0.00000739

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000116

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461610 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727132

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.000112 AC: 5 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53140

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Developmental and epileptic encephalopathy, 1;C3892048:Autosomal dominant nonsyndromic hearing loss 65;na:Caused by mutation in the TBC1 domain family, member 24 (1)
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.067
BayesDel_addAF	Benign	-0.42	T
BayesDel_noAF	Benign	-0.62
CADD	Benign	16
DANN	Benign	0.91
DEOGEN2	Benign	0.0012	T
Eigen	Benign	-0.31
Eigen_PC	Benign	-0.26
FATHMM_MKL	Benign	0.72	D
LIST_S2	Benign	0.79	T
M_CAP	Benign	0.0081	T
MetaRNN	Benign	0.14	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.3	L
PhyloP100		3.4
PrimateAI	Benign	0.44	T
PROVEAN	Benign	-0.26	N
REVEL	Benign	0.052
Sift	Benign	0.39	T
Sift4G	Benign	0.43	T
Polyphen		0.54	P
Vest4		0.097
MutPred		0.42		Gain of phosphorylation at A277 (P = 0.032)
MVP		0.55
MPC		0.31
ClinPred		0.096	T
GERP RS		3.2
Varity_R		0.039
gMVP		0.25

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: rs754019727; hg19: chr16-2546978;