2-63605301-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_005917.4(MDH1):c.697G>A(p.Ala233Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,484 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MDH1 NM_005917.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.29

Genes affected

MDH1 (HGNC:6970): (malate dehydrogenase 1) This gene encodes an enzyme that catalyzes the NAD/NADH-dependent, reversible oxidation of malate to oxaloacetate in many metabolic pathways, including the citric acid cycle. Two main isozymes are known to exist in eukaryotic cells: one is found in the mitochondrial matrix and the other in the cytoplasm. This gene encodes the cytosolic isozyme, which plays a key role in the malate-aspartate shuttle that allows malate to pass through the mitochondrial membrane to be transformed into oxaloacetate for further cellular processes. Alternatively spliced transcript variants have been found for this gene. A recent study showed that a C-terminally extended isoform is produced by use of an alternative in-frame translation termination codon via a stop codon readthrough mechanism, and that this isoform is localized in the peroxisomes. Pseudogenes have been identified on chromosomes X and 6. [provided by RefSeq, Feb 2016]

WDPCP (HGNC:28027): (WD repeat containing planar cell polarity effector) This gene encodes a cytoplasmic WD40 repeat protein. A similar gene in frogs encodes a planar cell polarity protein that plays a critical role in collective cell movement and ciliogenesis by mediating septin localization. Mutations in this gene are associated with Bardet-Biedl syndrome 15 and may also play a role in Meckel-Gruber syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jun 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MDH1	NM_005917.4	c.697G>A	p.Ala233Thr	missense_variant	7/9	ENST00000233114.13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MDH1	ENST00000233114.13	c.697G>A	p.Ala233Thr	missense_variant	7/9	1	NM_005917.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461484 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 727070

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.: 33

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

Oct 25, 2022

The c.751G>A (p.A251T) alteration is located in exon 7 (coding exon 7) of the MDH1 gene. This alteration results from a G to A substitution at nucleotide position 751, causing the alanine (A) at amino acid position 251 to be replaced by a threonine (T). 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	0.21
BayesDel_addAF	Uncertain	0.053	T
BayesDel_noAF	Benign	-0.16
Cadd	Uncertain	25
Dann	Pathogenic	1.0
DEOGEN2	Uncertain	0.77	D;T;T;.;.
Eigen	Pathogenic	0.72
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.98	D;D;D;D;D
M_CAP	Benign	0.053	D
MetaRNN	Uncertain	0.59	D;D;D;D;D
MetaSVM	Uncertain	0.14	D
MutationAssessor	Pathogenic	3.3	M;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Uncertain	0.64	T
PROVEAN	Uncertain	-3.3	D;D;D;D;D
REVEL	Uncertain	0.44
Sift	Uncertain	0.026	D;D;D;D;D
Sift4G	Uncertain	0.051	T;D;T;T;T
Polyphen		1.0	D;.;.;.;.
Vest4		0.56
MutPred		0.54		Gain of phosphorylation at A233 (P = 0.116);.;.;.;.;
MVP		0.78
MPC		0.73
ClinPred		0.98	D
GERP RS		4.6
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.7
Varity_R		0.33
gMVP		0.57

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: chr2-63832435;