9-6604613-G-T

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1PM2PP3_StrongPP5

The NM_000170.3(GLDC):c.1033C>A(p.Pro345Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,612,612 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 Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. P345P) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

GLDC
NM_000170.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2

Conservation

PhyloP100: 9.32

Publications

0 publications found

Variant links:

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]

GLDC Gene-Disease associations (from GenCC):

glycine encephalopathy
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Myriad Women’s Health, Labcorp Genetics (formerly Invitae), ClinGen
glycine encephalopathy 1
Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
infantile glycine encephalopathy
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
neonatal glycine encephalopathy
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
atypical glycine encephalopathy
Inheritance: Unknown Classification: SUPPORTIVE Submitted by: Orphanet

GLDC links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in NM_000170.3

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.96

PP5

Variant 9-6604613-G-T is Pathogenic according to our data. Variant chr9-6604613-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 554913.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000170.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GLDC	NM_000170.3	MANE Select	c.1033C>A	p.Pro345Thr	missense	Exon 7 of 25	NP_000161.2

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
GLDC	ENST00000321612.8	TSL:1 MANE Select	c.1033C>A	p.Pro345Thr	missense	Exon 7 of 25	ENSP00000370737.4
GLDC	ENST00000639443.1	TSL:1	n.601C>A		non_coding_transcript_exon	Exon 3 of 21
GLDC	ENST00000638654.1	TSL:3	c.280C>A	p.Pro94Thr	missense	Exon 2 of 4	ENSP00000491101.1

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152090

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000796

AC:

AN:

251356

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1460522

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

726598

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33450

American (AMR)

AF:

0.00

AC:

AN:

44716

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86204

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

4812

European-Non Finnish (NFE)

AF:

0.00000270

AC:

AN:

1111840

Other (OTH)

AF:

0.0000166

AC:

AN:

60248

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.450

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000132

AC:

AN:

152090

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74298

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41412

American (AMR)

AF:

0.00

AC:

AN:

15268

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4818

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10604

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68010

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.650

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Glycine encephalopathy

Pathogenic:1

Jan 23, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 345 of the GLDC protein (p.Pro345Thr). This variant is present in population databases (rs373263202, gnomAD 0.002%). This missense change has been observed in individual(s) with glycine encephalopathy (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: 554913). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt GLDC protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic.

not specified

Uncertain:1

Jun 13, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: GLDC c.1033C>A (p.Pro345Thr) results in a non-conservative amino acid change located in the Glycine cleavage system P-protein, N-terminal domain (IPR049315) of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be disruptive. The variant allele was found at a frequency of 8e-06 in 251356 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1033C>A has been reported in the literature in at-least one compound heterozygous individual affected with Glycine Encephalopathy (Non-Ketotic Hyperglycinemia) (example: Coughlin_2017). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 27362913). ClinVar contains an entry for this variant (Variation ID: 554913). Based on the evidence outlined above, the variant was classified as uncertain significance.

Glycine encephalopathy 1

Uncertain:1

Nov 08, 2017

Counsyl

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.93

BayesDel_addAF

Pathogenic

0.57

BayesDel_noAF

Pathogenic

0.60

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.90

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.99

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.99

M_CAP

Pathogenic

0.79

MetaRNN

Pathogenic

0.96

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

4.6

PhyloP100

9.3

PrimateAI

Uncertain

0.77

PROVEAN

Pathogenic

-7.9

REVEL

Pathogenic

0.98

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.98

MVP

1.0

MPC

0.33

ClinPred

1.0

GERP RS

5.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.98

gMVP

0.93

Mutation Taster

=9/91

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over