14-75902152-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_015072.5(TTLL5):c.3751G>A(p.Ala1251Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000155 in 1,614,002 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 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. A1251V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000016 (0 hom.)
• Consequence: TTLL5 NM_015072.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -2.70

Genes affected

TTLL5 (HGNC:19963): (tubulin tyrosine ligase like 5) This gene encodes a member of the tubulin tyrosine ligase like protein family. This protein interacts with two glucocorticoid receptor coactivators, transcriptional intermediary factor 2 and steroid receptor coactivator 1. This protein may function as a coregulator of glucocorticoid receptor mediated gene induction and repression. This protein may also function as an alpha tubulin polyglutamylase.[provided by RefSeq, Feb 2010]

IFT43 (HGNC:29669): (intraflagellar transport 43) This gene encodes a subunit of the intraflagellar transport complex A (IFT-A). IFT-A is a multiprotein complex that plays an important role in cilia assembly and maintenance by mediating retrograde ciliary transport. Mutations in this gene are a cause of cranioectodermal dysplasia-3 (CED3), also known as Sensenbrenner syndrome. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Dec 2011]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.010039866).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTLL5	NM_015072.5	c.3751G>A	p.Ala1251Thr	missense_variant	31/32	ENST00000298832.14

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTLL5	ENST00000298832.14	c.3751G>A	p.Ala1251Thr	missense_variant	31/32	1	NM_015072.5	P4

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152148 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.0000157 AC: 23 AN: 1461854 Hom.: 0 Cov.: 30 AF XY: 0.0000124 AC XY: 9 AN XY: 727234

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.0000224

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: 0.0000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152148 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74310

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000151

TwinsUK AF: 0.00 AC: 0

ALSPAC AF: 0.000259 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 01, 2021

This sequence change replaces alanine with threonine at codon 1251 of the TTLL5 protein (p.Ala1251Thr). The alanine residue is weakly conserved and there is a small physicochemical difference between alanine and threonine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with TTLL5-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The threonine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.064
BayesDel_addAF	Benign	-0.45	T
BayesDel_noAF	Benign	-0.89
Cadd	Benign	0.055
Dann	Benign	0.75
DEOGEN2	Benign	0.0097	T
Eigen	Benign	-2.1
Eigen_PC	Benign	-2.1
FATHMM_MKL	Benign	0.0055	N
LIST_S2	Benign	0.66	T
M_CAP	Benign	0.0025	T
MetaRNN	Benign	0.010	T
MetaSVM	Benign	-0.96	T
MutationAssessor	Benign	-0.26	N
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.21	T
PROVEAN	Benign	0.16	N
REVEL	Benign	0.052
Sift	Benign	1.0	T
Sift4G	Benign	0.92	T
Polyphen		0.0	B
Vest4		0.026
MutPred		0.064		Gain of relative solvent accessibility (P = 0.0166);
MVP		0.030
MPC		0.085
ClinPred		0.060	T
GERP RS		-11
Varity_R		0.022
gMVP		0.17

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

Publications

LitVar

Other links and lift over

dbSNP: rs749147754; hg19: chr14-76368495; COSMIC: COSV54039933;