5-81255051-G-A

Variant names:

• chr5-81255051-G-A
• rs576895568
• NM_001099735.2:c.506G>A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_001099735.2(CKMT2):​c.506G>A​(p.Arg169His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000173 in 1,613,924 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000016 (0 hom.)
• Consequence: CKMT2 NM_001099735.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.60

Genes affected

CKMT2 (HGNC:1996): (creatine kinase, mitochondrial 2) Mitochondrial creatine kinase (MtCK) is responsible for the transfer of high energy phosphate from mitochondria to the cytosolic carrier, creatine. It belongs to the creatine kinase isoenzyme family. It exists as two isoenzymes, sarcomeric MtCK and ubiquitous MtCK, encoded by separate genes. Mitochondrial creatine kinase occurs in two different oligomeric forms: dimers and octamers, in contrast to the exclusively dimeric cytosolic creatine kinase isoenzymes. Sarcomeric mitochondrial creatine kinase has 80% homology with the coding exons of ubiquitous mitochondrial creatine kinase. This gene contains sequences homologous to several motifs that are shared among some nuclear genes encoding mitochondrial proteins and thus may be essential for the coordinated activation of these genes during mitochondrial biogenesis. Three transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2008]

CKMT2-AS1 (HGNC:48997): (CKMT2 antisense RNA 1)

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.979

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CKMT2	NM_001099735.2	c.506G>A	p.Arg169His	missense_variant	Exon 5 of 10	ENST00000254035.9	NP_001093205.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CKMT2	ENST00000254035.9	c.506G>A	p.Arg169His	missense_variant	Exon 5 of 10	1	NM_001099735.2	ENSP00000254035.4

Frequencies

GnomAD3 genomes AF: 0.0000328 AC: 5 AN: 152208 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000579

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000359 AC: 9 AN: 250510 Hom.: 0 AF XY: 0.0000295 AC XY: 4 AN XY: 135596

Gnomad AFR exome AF: 0.0000619

Gnomad AMR exome AF: 0.000116

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000109

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000885

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000157 AC: 23 AN: 1461598 Hom.: 0 Cov.: 31 AF XY: 0.0000165 AC XY: 12 AN XY: 727094

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.000112

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000756

Gnomad4 SAS exome AF: 0.0000348

Gnomad4 FIN exome AF: 0.0000188

Gnomad4 NFE exome AF: 0.00000719

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000328 AC: 5 AN: 152326 Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3 AN XY: 74490

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000580

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000529

ExAC AF: 0.0000494 AC: 6

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

May 03, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.506G>A (p.R169H) alteration is located in exon 6 (coding exon 4) of the CKMT2 gene. This alteration results from a G to A substitution at nucleotide position 506, causing the arginine (R) at amino acid position 169 to be replaced by a histidine (H). 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	Pathogenic	0.17	D
BayesDel_noAF	Pathogenic	0.24
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.50	T;.;T;T
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	1.0	.;D;D;.
M_CAP	Benign	0.084	D
MetaRNN	Pathogenic	0.98	D;D;D;D
MetaSVM	Uncertain	0.11	D
MutationAssessor	Pathogenic	4.0	H;.;H;H
PrimateAI	Pathogenic	0.83	D
PROVEAN	Pathogenic	-4.8	D;D;D;D
REVEL	Uncertain	0.59
Sift	Uncertain	0.0040	D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	D;.;D;D
Vest4		0.99
MutPred		0.97		Loss of MoRF binding (P = 0.0133);Loss of MoRF binding (P = 0.0133);Loss of MoRF binding (P = 0.0133);Loss of MoRF binding (P = 0.0133);
MVP		0.87
MPC		1.2
ClinPred		0.99	D
GERP RS		4.9
Varity_R		0.79
gMVP		0.86

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: rs576895568; hg19: chr5-80550870;