chr14-50302999-G-T

Variant names:

• chr14-50302999-G-T
• rs2297995
• NM_024884.3:c.159C>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_024884.3(L2HGDH):​c.159C>A​(p.Ile53Ile) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,459,060 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. I53I) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: L2HGDH NM_024884.3 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.255
• Publications: 33 publications found

Genes affected

L2HGDH (HGNC:20499): (L-2-hydroxyglutarate dehydrogenase) This gene encodes L-2-hydroxyglutarate dehydrogenase, a FAD-dependent enzyme that oxidizes L-2-hydroxyglutarate to alpha-ketoglutarate in a variety of mammalian tissues. Mutations in this gene cause L-2-hydroxyglutaric aciduria, a rare autosomal recessive neurometabolic disorder resulting in moderate to severe cognitive disability. [provided by RefSeq, Jul 2008]

L2HGDH Gene-Disease associations (from GenCC):

• L-2-hydroxyglutaric aciduria

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Orphanet
• mitochondrial disease

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
L2HGDH	NM_024884.3	c.159C>A	p.Ile53Ile	synonymous_variant	Exon 2 of 10	ENST00000267436.9	NP_079160.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
L2HGDH	ENST00000267436.9	c.159C>A	p.Ile53Ile	synonymous_variant	Exon 2 of 10	1	NM_024884.3	ENSP00000267436.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459060 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726120

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33414

American (AMR) AF: 0.0000224 AC: 1 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26118

East Asian (EAS) AF: 0.00 AC: 0 AN: 39680

South Asian (SAS) AF: 0.00 AC: 0 AN: 86220

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53360

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1109470

Other (OTH) AF: 0.00 AC: 0 AN: 60312

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 68365

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.54
CADD	Benign	0.16
DANN	Benign	0.60
PhyloP100		-0.26

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.44		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.44		Position offset: 18

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

Other links and lift over

dbSNP: rs2297995; hg19: chr14-50769717;