NM_000098.3:c.509_510delTTinsGC

Variant names:

• chr1-53210183-TT-GC
• rs1553169607
• NM_000098.3:c.509_510delTTinsGC

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1

The NM_000098.3(CPT2):​c.509_510delTTinsGC​(p.Leu170Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. The variant is present in control chromosomes in GnomAd MNV project. The variant allele was found at a frequency of 0.0000199 in 5 alleles, including 0 homozygotes. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Uncertain significance (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar.

• Frequency: GnomAD MNV: 𝑓 0.000020 Genomes: not found (cov: 32)
• Consequence: CPT2 NM_000098.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.15
• Publications: 0 publications found

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]

CPT2 Gene-Disease associations (from GenCC):

• carnitine palmitoyltransferase II deficiency

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, Myriad Women’s Health
• carnitine palmitoyl transferase II deficiency, myopathic form

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, PanelApp Australia
• carnitine palmitoyl transferase II deficiency, neonatal form

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), PanelApp Australia
• carnitine palmitoyl transferase II deficiency, severe infantile form

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Orphanet
• encephalopathy, acute, infection-induced, susceptibility to, 4

  Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ENSG00000236723 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 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, 6 uncertain in NM_000098.3

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CPT2	NM_000098.3	c.509_510delTTinsGC	p.Leu170Arg	missense_variant		ENST00000371486.4	NP_000089.1
CPT2	NM_001330589.2	c.509_510delTTinsGC	p.Leu170Arg	missense_variant			NP_001317518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CPT2	ENST00000371486.4	c.509_510delTTinsGC	p.Leu170Arg	missense_variant		1	NM_000098.3	ENSP00000360541.3

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

GnomAD MNV AF: 0.0000199 AC: 5 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Carnitine palmitoyltransferase II deficiency Uncertain:1

Jan 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 170 of the CPT2 protein (p.Leu170Arg). This variant is present in population databases (no rsID available, gnomAD 0.002%). 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: 529863). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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
PhyloP100		3.2

Splicing

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

Other links and lift over

dbSNP: rs1553169607; hg19: chr1-53675855;