NM_018196.4:c.830C>T

Variant names:

• chrX-155507063-G-A
• rs1603011521
• NM_018196.4:c.830C>T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_018196.4(TMLHE):​c.830C>T​(p.Ala277Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 22)
• Consequence: TMLHE NM_018196.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.57

Genes affected

TMLHE (HGNC:18308): (trimethyllysine hydroxylase, epsilon) This gene encodes the protein trimethyllysine dioxygenase which is the first enzyme in the carnitine biosynthesis pathway. Carnitine play an essential role in the transport of activated fatty acids across the inner mitochondrial membrane. The encoded protein converts trimethyllysine into hydroxytrimethyllysine. A pseudogene of this gene is found on chromosome X. Alternate splicing results in multiple transcript variants.[provided by RefSeq, May 2010]

TMLHE-AS1 (HGNC:44261): (TMLHE antisense RNA 1)

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.794

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TMLHE	NM_018196.4	c.830C>T	p.Ala277Val	missense_variant	Exon 6 of 8	ENST00000334398.8	NP_060666.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMLHE	ENST00000334398.8	c.830C>T	p.Ala277Val	missense_variant	Exon 6 of 8	1	NM_018196.4	ENSP00000335261.3
TMLHE	ENST00000369439.4	c.830C>T	p.Ala277Val	missense_variant	Exon 6 of 7	1		ENSP00000358447.4
TMLHE	ENST00000675642.1	c.863C>T	p.Ala288Val	missense_variant	Exon 7 of 9			ENSP00000502604.1
TMLHE-AS1	ENST00000452506.1	n.67+17674G>A		intron_variant	Intron 1 of 1	5

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 22

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Feb 13, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.830C>T (p.A277V) alteration is located in exon 6 (coding exon 5) of the TMLHE gene. This alteration results from a C to T substitution at nucleotide position 830, causing the alanine (A) at amino acid position 277 to be replaced by a valine (V). 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	Benign	0.29
BayesDel_addAF	Uncertain	0.077	D
BayesDel_noAF	Benign	-0.13
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Benign	0.20	T;.
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.95	D;D
M_CAP	Uncertain	0.091	D
MetaRNN	Pathogenic	0.79	D;D
MetaSVM	Benign	-0.38	T
MutationAssessor	Benign	1.2	L;L
PrimateAI	Uncertain	0.77	T
PROVEAN	Benign	-1.4	N;N
REVEL	Uncertain	0.57
Sift	Benign	0.19	T;T
Sift4G	Benign	0.68	T;T
Polyphen		0.99	D;D
Vest4		0.77
MutPred		0.67		Gain of stability (P = 0.0932);Gain of stability (P = 0.0932);
MVP		0.97
MPC		0.80
ClinPred		0.94	D
GERP RS		4.4
Varity_R		0.51
gMVP		0.75

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

Other links and lift over

dbSNP: rs1603011521; hg19: chrX-154736724;