9-6533030-C-A

Variant summary

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

The NM_000170.3(GLDC):c.3050G>T(p.Arg1017Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000171 in 1,459,140 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1017K) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.000017 (0 hom.)
• Consequence: GLDC NM_000170.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.04

Genes affected

GLDC (HGNC:4313): (glycine decarboxylase) Degradation of glycine is brought about by the glycine cleavage system, which is composed of four mitochondrial protein components: P protein (a pyridoxal phosphate-dependent glycine decarboxylase), H protein (a lipoic acid-containing protein), T protein (a tetrahydrofolate-requiring enzyme), and L protein (a lipoamide dehydrogenase). The protein encoded by this gene is the P protein, which binds to glycine and enables the methylamine group from glycine to be transferred to the T protein. Defects in this gene are a cause of nonketotic hyperglycinemia (NKH).[provided by RefSeq, Jan 2010]

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
GLDC	NM_000170.3	c.3050G>T	p.Arg1017Met	missense_variant	25/25	ENST00000321612.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GLDC	ENST00000321612.8	c.3050G>T	p.Arg1017Met	missense_variant	25/25	1	NM_000170.3	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.0000171 AC: 25 AN: 1459140 Hom.: 0 Cov.: 29 AF XY: 0.0000179 AC XY: 13 AN XY: 726110

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: 0.0000225

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Non-ketotic hyperglycinemia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 24, 2021

This variant has not been reported in the literature in individuals affected with GLDC-related conditions. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt GLDC protein function. This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with methionine at codon 1017 of the GLDC protein (p.Arg1017Met). The arginine residue is moderately conserved and there is a moderate physicochemical difference between arginine and methionine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.040
Cadd	Pathogenic	26
Dann	Benign	0.96
DEOGEN2	Benign	0.27	T;.;.;.
Eigen	Uncertain	0.43
Eigen_PC	Uncertain	0.44
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Benign	0.83	T;T;T;T
M_CAP	Benign	0.077	D
MetaRNN	Uncertain	0.42	T;T;T;T
MetaSVM	Uncertain	0.21	D
MutationAssessor	Benign	0.0	N;.;.;.
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-0.46	N;.;.;.
REVEL	Uncertain	0.50
Sift	Uncertain	0.0030	D;.;.;.
Sift4G	Uncertain	0.0030	D;.;.;.
Polyphen		0.93	P;.;.;.
Vest4		0.64
MutPred		0.12		Loss of methylation at K1016 (P = 0.0355);.;.;.;
MVP		0.95
MPC		0.21
ClinPred		0.77	D
GERP RS		5.4
Varity_R		0.24
gMVP		0.78

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: chr9-6533030;