rs386833560

Positions:

• chr9-6550883-G-A

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1 PM2 PM5 PP3_Moderate PP5_Very_Strong

The NM_000170.3(GLDC):​c.2489C>T​(p.Thr830Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,612,996 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T830K) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000010 (0 hom.)
• Consequence: GLDC NM_000170.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 9.36

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 Pathogenic. Variant got 16 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000170.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-6550883-G-T is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.916
• PP5: Variant 9-6550883-G-A is Pathogenic according to our data. Variant chr9-6550883-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 56079.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr9-6550883-G-A is described in Lovd as [Pathogenic]. Variant chr9-6550883-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GLDC	NM_000170.3	c.2489C>T	p.Thr830Met	missense_variant	21/25	ENST00000321612.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GLDC	ENST00000321612.8	c.2489C>T	p.Thr830Met	missense_variant	21/25	1	NM_000170.3	P1

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152112 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000239 AC: 6 AN: 251478 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135910

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000217

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000103 AC: 15 AN: 1460884 Hom.: 0 Cov.: 30 AF XY: 0.0000124 AC XY: 9 AN XY: 726866

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000756

Gnomad4 SAS exome AF: 0.0000348

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000630

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000329 AC: 5 AN: 152112 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74304

Gnomad4 AFR AF: 0.0000483

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.0000302

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Non-ketotic hyperglycinemia Pathogenic:4

Likely pathogenic, criteria provided, single submitter	clinical testing	Centre for Translational Omics - GOSgene, University College London	Mar 16, 2018	- -
Likely pathogenic, no assertion criteria provided	literature only	Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 09, 2024	This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 830 of the GLDC protein (p.Thr830Met). This variant is present in population databases (rs386833560, gnomAD 0.03%). This missense change has been observed in individual(s) with non-ketotic hyperglycinemia (PMID: 27362913). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 56079). 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 expected to disrupt GLDC protein function with a positive predictive value of 80%. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.79
BayesDel_addAF	Uncertain	0.041	T
BayesDel_noAF	Uncertain	0.11
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.74	D;.;.;.
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D;D
M_CAP	Uncertain	0.29	D
MetaRNN	Pathogenic	0.92	D;D;D;D
MetaSVM	Pathogenic	0.95	D
MutationAssessor	Pathogenic	4.1	H;.;.;.
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.56	T
PROVEAN	Pathogenic	-4.8	D;.;.;.
REVEL	Pathogenic	0.80
Sift	Pathogenic	0.0	D;.;.;.
Sift4G	Pathogenic	0.0	D;.;.;.
Polyphen		1.0	D;.;.;.
Vest4		0.72
MVP		0.98
MPC		0.26
ClinPred		0.99	D
GERP RS		4.7
Varity_R		0.82
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

LitVar

Other links and lift over

dbSNP: rs386833560; hg19: chr9-6550883; COSMIC: COSV58679063;