Genetic Variant TTLL1:p.Thr334Met (chr22-43046551-G-A) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_012263.5(TTLL1):c.1001C>T(p.Thr334Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000316 in 1,614,100 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000031 ( 0 hom. )

Consequence

TTLL1
NM_012263.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.04

Variant links:

Genes affected

TTLL1 (HGNC:1312): (TTL family tubulin polyglutamylase complex subunit L1) Predicted to enable tubulin binding activity and tubulin-glutamic acid ligase activity. Predicted to be involved in microtubule cytoskeleton organization and protein polyglutamylation. Predicted to act upstream of or within several processes, including cerebellar Purkinje cell differentiation; mucociliary clearance; and regulation of blastocyst development. Predicted to be located in cytoplasm; extracellular region; and microtubule cytoskeleton. Predicted to be active in cilium. [provided by Alliance of Genome Resources, Apr 2022]

TTLL1 links:

TTLL1-AS1 (HGNC:40111): (TTLL1 antisense RNA 1)

TTLL1-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTLL1	NM_012263.5 link	c.1001C>T	p.Thr334Met	missense_variant	Exon 10 of 11	ENST00000266254.12	NP_036395.1	O95922-1A0A024R4U6
TTLL1	NR_027779.2 link	n.1309C>T		non_coding_transcript_exon_variant	Exon 11 of 12
TTLL1-AS1	NR_125362.1 link	n.1771+5250G>A		intron_variant	Intron 2 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTLL1	ENST00000266254.12 link	c.1001C>T	p.Thr334Met	missense_variant	Exon 10 of 11	1	NM_012263.5	ENSP00000266254.7		O95922-1

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152170

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000192

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000597

AC:

AN:

251402

Hom.:

AF XY:

0.0000810

AC XY:

AN XY:

135874

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.0000653

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000615

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000315

AC:

AN:

1461812

Hom.:

Cov.:

AF XY:

0.0000399

AC XY:

AN XY:

727204

show subpopulations

Gnomad4 AFR exome

AF:

0.000119

Gnomad4 AMR exome

AF:

0.0000894

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000812

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000270

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000328

AC:

AN:

152288

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74456

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.0000529

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000576

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

May 26, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1001C>T (p.T334M) alteration is located in exon 10 (coding exon 8) of the TTLL1 gene. This alteration results from a C to T substitution at nucleotide position 1001, causing the threonine (T) at amino acid position 334 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.46

BayesDel_addAF

Benign

-0.21

BayesDel_noAF

Benign

-0.31

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.27

T;.

Eigen

Pathogenic

0.75

Eigen_PC

Pathogenic

0.67

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.98

D;D

M_CAP

Benign

0.071

MetaRNN

Uncertain

0.69

D;D

MetaSVM

Benign

-1.0

MutationAssessor

Uncertain

2.6

M;.

PrimateAI

Uncertain

0.76

PROVEAN

Uncertain

-3.7

D;D

REVEL

Uncertain

0.34

Sift

Uncertain

0.0030

D;D

Sift4G

Uncertain

0.0030

D;D

Polyphen

1.0

D;D

Vest4

0.73

MVP

0.25

MPC

1.2

ClinPred

0.82

GERP RS

4.5

Varity_R

0.35

gMVP

0.80

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.26

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.26

Position offset: -7

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over