15-43596485-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001375484.1(CKMT1B):c.830G>A(p.Gly277Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000686 in 1,458,186 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 (★).

• Frequency:
  • Genomes: not found (cov: 26)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: CKMT1B NM_001375484.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.99

Genes affected

CKMT1B (HGNC:1995): (creatine kinase, mitochondrial 1B) Mitochondrial creatine (MtCK) kinase 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. Many malignant cancers with poor prognosis have shown overexpression of ubiquitous mitochondrial creatine kinase; this may be related to high energy turnover and failure to eliminate cancer cells via apoptosis. Ubiquitous mitochondrial creatine kinase has 80% homology with the coding exons of sarcomeric mitochondrial creatine kinase. Two genes located near each other on chromosome 15 have been identified which encode identical mitochondrial creatine kinase proteins. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.928

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CKMT1B	NM_001375484.1	c.830G>A	p.Gly277Asp	missense_variant	6/9	ENST00000441322.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CKMT1B	ENST00000441322.6	c.830G>A	p.Gly277Asp	missense_variant	6/9	1	NM_001375484.1	P1
CKMT1B	ENST00000300283.10	c.830G>A	p.Gly277Asp	missense_variant	7/10	5		P1
CKMT1B	ENST00000627381.1	c.830G>A	p.Gly277Asp	missense_variant	6/7	5
CKMT1B	ENST00000437534.3	c.830G>A	p.Gly277Asp	missense_variant, NMD_transcript_variant	6/9	2

Frequencies

GnomAD3 genomes Cov.: 26

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1458186 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 725526

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 26

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 16, 2023

The c.830G>A (p.G277D) alteration is located in exon 7 (coding exon 6) of the CKMT1B gene. This alteration results from a G to A substitution at nucleotide position 830, causing the glycine (G) at amino acid position 277 to be replaced by an aspartic acid (D). 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
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.090
Cadd	Pathogenic	26
Dann	Uncertain	1.0
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Benign	0.079	D
MetaRNN	Pathogenic	0.93	D;D;D
MetaSVM	Benign	-0.75	T
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-6.7	D;D;.
REVEL	Uncertain	0.60
Sift	Benign	0.068	T;T;.
Sift4G	Uncertain	0.058	T;T;T
Vest4		0.96
MutPred		0.79		Loss of catalytic residue at G277 (P = 0.0256);Loss of catalytic residue at G277 (P = 0.0256);Loss of catalytic residue at G277 (P = 0.0256);
MVP		0.76
MPC		2.2
ClinPred		0.99	D
GERP RS		4.5
gMVP		0.90

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr15-43888683;