1-53210798-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_000098.3(CPT2):c.1124G>T(p.Gly375Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,878 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. G375D) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: CPT2 NM_000098.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:7
• Conservation: PhyloP100: 10.0

Genes affected

CPT2 (HGNC:2330): (carnitine palmitoyltransferase 2) The protein encoded by this gene is a nuclear protein which is transported to the mitochondrial inner membrane. Together with carnitine palmitoyltransferase I, the encoded protein oxidizes long-chain fatty acids in the mitochondria. Defects in this gene are associated with mitochondrial long-chain fatty-acid (LCFA) oxidation disorders. [provided by RefSeq, Jul 2008]

(HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000098.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.929

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CPT2	NM_000098.3	c.1124G>T	p.Gly375Val	missense_variant	4/5	ENST00000371486.4
CPT2	NM_001330589.2	c.1124G>T	p.Gly375Val	missense_variant	4/5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CPT2	ENST00000371486.4	c.1124G>T	p.Gly375Val	missense_variant	4/5	1	NM_000098.3	P1
	ENST00000629810.1	n.286-389C>A		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251394 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135878

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000868

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS 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: 0.00000274 AC: 4 AN: 1461878 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727238

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000894

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Carnitine palmitoyl transferase II deficiency, myopathic form;C1833511:Carnitine palmitoyl transferase II deficiency, severe infantile form;C1833518:Carnitine palmitoyl transferase II deficiency, neonatal form;C3280160:Encephalopathy, acute, infection-induced, susceptibility to, 4 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Nov 24, 2021

- -

Carnitine palmitoyl transferase II deficiency, neonatal form Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 17, 2022

The c.1124G>T (p.G375V) alteration is located in exon 4 (coding exon 4) of the CPT2 gene. This alteration results from a G to T substitution at nucleotide position 1124, causing the glycine (G) at amino acid position 375 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Carnitine palmitoyl transferase II deficiency, myopathic form Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

Encephalopathy, acute, infection-induced, susceptibility to, 4 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

Carnitine palmitoyl transferase II deficiency, severe infantile form Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

Carnitine palmitoyltransferase II deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 01, 2022

This sequence change replaces glycine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 375 of the CPT2 protein (p.Gly375Val). This variant is present in population databases (rs772843417, gnomAD 0.009%). This variant has not been reported in the literature in individuals affected with CPT2-related conditions. ClinVar contains an entry for this variant (Variation ID: 1423479). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CPT2 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	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.40
Cadd	Pathogenic	27
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.60	D;.;.;T;T
Eigen	Uncertain	0.66
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;D;D;D;D
M_CAP	Uncertain	0.13	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D
MetaSVM	Uncertain	0.31	D
MutationAssessor	Benign	1.6	L;.;.;.;.
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.63	T
PROVEAN	Pathogenic	-8.6	D;.;.;.;.
REVEL	Pathogenic	0.77
Sift	Pathogenic	0.0	D;.;.;.;.
Sift4G	Pathogenic	0.0	D;.;.;.;.
Polyphen		1.0	D;.;.;.;.
Vest4		0.96
MutPred		0.73		Loss of catalytic residue at G375 (P = 0.0778);Loss of catalytic residue at G375 (P = 0.0778);Loss of catalytic residue at G375 (P = 0.0778);Loss of catalytic residue at G375 (P = 0.0778);Loss of catalytic residue at G375 (P = 0.0778);
MVP		0.99
MPC		0.62
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.95
gMVP		0.76

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: rs772843417; hg19: chr1-53676470;