2-63605370-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_005917.4(MDH1):c.766G>A(p.Asp256Asn) variant causes a missense change. The variant allele was found at a frequency of 0.000242 in 1,614,088 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00018 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00025 (0 hom.)
• Consequence: MDH1 NM_005917.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.50

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2518741).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MDH1	NM_005917.4	c.766G>A	p.Asp256Asn	missense_variant	7/9	ENST00000233114.13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MDH1	ENST00000233114.13	c.766G>A	p.Asp256Asn	missense_variant	7/9	1	NM_005917.4	P1

Frequencies

GnomAD3 genomes AF: 0.000177 AC: 27 AN: 152216 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.000121

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000115 AC: 29 AN: 251256 Hom.: 0 AF XY: 0.000110 AC XY: 15 AN XY: 135820

Gnomad AFR exome AF: 0.000123

Gnomad AMR exome AF: 0.00

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: 0.000238

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000249 AC: 364 AN: 1461754 Hom.: 0 Cov.: 30 AF XY: 0.000256 AC XY: 186 AN XY: 727186

Gnomad4 AFR exome AF: 0.0000299

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: 0.0000374

Gnomad4 NFE exome AF: 0.000317

Gnomad4 OTH exome AF: 0.000149

GnomAD4 genome AF: 0.000177 AC: 27 AN: 152334 Hom.: 0 Cov.: 33 AF XY: 0.000134 AC XY: 10 AN XY: 74492

Gnomad4 AFR AF: 0.000120

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000163 Hom.: 0

Bravo AF: 0.000121

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.000165 AC: 20

EpiCase AF: 0.000164

EpiControl AF: 0.0000593

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

Dec 28, 2023

The c.820G>A (p.D274N) 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 820, causing the aspartic acid (D) at amino acid position 274 to be replaced by an asparagine (N). 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	Uncertain	0.41
BayesDel_addAF	Benign	-0.38	T
BayesDel_noAF	Benign	-0.49
Cadd	Uncertain	25
Dann	Pathogenic	1.0
DEOGEN2	Uncertain	0.79	D;T;T;.;.
Eigen	Uncertain	0.31
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.93	D;D;D;D;D
M_CAP	Benign	0.024	T
MetaRNN	Benign	0.25	T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Uncertain	2.5	M;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Uncertain	0.77	T
PROVEAN	Uncertain	-3.6	D;D;D;D;D
REVEL	Benign	0.22
Sift	Benign	0.044	D;D;D;D;D
Sift4G	Benign	0.067	T;T;T;T;T
Polyphen		1.0	D;.;.;.;.
Vest4		0.47
MVP		0.61
MPC		0.44
ClinPred		0.22	T
GERP RS		4.8
Varity_R		0.37
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: rs116232314; hg19: chr2-63832504;