Genetic Variant TTLL1:p.His256Arg (chr22-43059508-T-C) – 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.767A>G(p.His256Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000753 in 1,461,250 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

TTLL1
NM_012263.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.95

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:

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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.767A>G	p.His256Arg	missense_variant	Exon 8 of 11	ENST00000266254.12	NP_036395.1	O95922-1A0A024R4U6
TTLL1	NR_027779.2 link	n.1075A>G		non_coding_transcript_exon_variant	Exon 9 of 12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTLL1	ENST00000266254.12 link	c.767A>G	p.His256Arg	missense_variant	Exon 8 of 11	1	NM_012263.5	ENSP00000266254.7		O95922-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000401

AC:

AN:

249084

Hom.:

AF XY:

0.00

AC XY:

AN XY:

134608

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000328

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000753

AC:

AN:

1461250

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

726894

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000899

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Aug 04, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.767A>G (p.H256R) alteration is located in exon 8 (coding exon 6) of the TTLL1 gene. This alteration results from a A to G substitution at nucleotide position 767, causing the histidine (H) at amino acid position 256 to be replaced by an arginine (R). 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

Pathogenic

0.99

BayesDel_addAF

Uncertain

0.068

BayesDel_noAF

Uncertain

-0.040

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.28

T;.

Eigen

Uncertain

0.50

Eigen_PC

Uncertain

0.54

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.84

T;D

M_CAP

Benign

0.018

MetaRNN

Uncertain

0.69

D;D

MetaSVM

Uncertain

-0.15

MutationAssessor

Uncertain

2.6

M;M

PrimateAI

Pathogenic

0.82

PROVEAN

Pathogenic

-7.2

D;D

REVEL

Uncertain

0.44

Sift

Uncertain

0.0010

D;D

Sift4G

Uncertain

0.049

D;T

Polyphen

0.99

D;P

Vest4

0.70

MutPred

0.56

Gain of solvent accessibility (P = 0.0074);Gain of solvent accessibility (P = 0.0074);

MVP

0.57

MPC

1.4

ClinPred

0.99

GERP RS

5.3

Varity_R

0.85

gMVP

0.67

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

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