rs386833587

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong

The NM_000170.3(GLDC):​c.806C>T​(p.Thr269Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000036 in 1,613,244 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. T269T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000038 ( 0 hom. )

Consequence

GLDC
NM_000170.3 missense

Scores

14
4

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:11O:1

Conservation

PhyloP100: 7.46

Publications

6 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

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ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 uncertain in NM_000170.3
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.981
PP5
Variant 9-6605186-G-A is Pathogenic according to our data. Variant chr9-6605186-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 56104.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GLDCNM_000170.3 linkc.806C>T p.Thr269Met missense_variant Exon 6 of 25 ENST00000321612.8 NP_000161.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GLDCENST00000321612.8 linkc.806C>T p.Thr269Met missense_variant Exon 6 of 25 1 NM_000170.3 ENSP00000370737.4

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
151986
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251468
AF XY:
0.0000294
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:
0.0000462
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000383
AC:
56
AN:
1461258
Hom.:
0
Cov.:
31
AF XY:
0.0000385
AC XY:
28
AN XY:
727004
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33456
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86244
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5594
European-Non Finnish (NFE)
AF:
0.0000450
AC:
50
AN:
1111628
Other (OTH)
AF:
0.0000663
AC:
4
AN:
60362
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.452
Heterozygous variant carriers
0
3
6
9
12
15
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
2
AN:
151986
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74222
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41380
American (AMR)
AF:
0.00
AC:
0
AN:
15234
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5174
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4814
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10578
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68016
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000203
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:11Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Glycine encephalopathy Pathogenic:5Other:1
Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

Sep 16, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

GenomeConnect - Brain Gene Registry
Significance:not provided
Review Status:no classification provided
Collection Method:phenotyping only

Variant classified as Pathogenic and reported on 07-23-2022 by GeneDx. Assertions are reported exactly as they appear on the patient provided laboratory report. GenomeConnect does not attempt to reinterpret the variant. The IDDRC-CTSA National Brain Gene Registry (BGR) is a study funded by the U.S. National Center for Advancing Translational Sciences (NCATS) and includes 13 Intellectual and Developmental Disability Research Center (IDDRC) institutions. The study is led by Principal Investigator Dr. Philip Payne from Washington University. The BGR is a data commons of gene variants paired with subject clinical information. This database helps scientists learn more about genetic changes and their impact on the brain and behavior. Participation in the Brain Gene Registry requires participation in GenomeConnect. More information about the Brain Gene Registry can be found on the study website - https://braingeneregistry.wustl.edu/.

Oct 22, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 269 of the GLDC protein (p.Thr269Met). This variant is present in population databases (rs386833587, gnomAD 0.006%). This missense change has been observed in individual(s) with nonketotic hyperglycinemia (PMID: 16450403, 16601880, 27362913). ClinVar contains an entry for this variant (Variation ID: 56104). 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) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on GLDC protein function. Experimental studies have shown that this missense change affects GLDC function (PMID: 26179960). For these reasons, this variant has been classified as Pathogenic.

Sep 28, 2018
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: GLDC c.806C>T (p.Thr269Met) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.6e-05 in 246244 control chromosomes. c.806C>T has been reported in the literature in multiple individuals affected with Glycine Encephalopathy (Non-Ketotic Hyperglycinemia) both as a compound heterozygous and homozygous allele (Conter_2006, Coughlin_2017). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on residual enzyme activity, where <10% of normal activity was observed in vitro (Swanson_2015). One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation and classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic.

Jul 07, 2023
Genetics and Molecular Pathology, SA Pathology
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The GLDC c.806C>T variant is classified as PATHOGENIC (PS3, PS4, PP3) The GLDC c.806C>T variant is a single nucleotide change in exon 6/25 of the GLDC gene, which is predicted to change the amino acid threonine at position 269 in the protein to methionine. This variant has been reported in both homozygous and compound heterozygous state in multiple individuals with Glycine encephalopathy (PMID:16450403, PMID:16601880, PMID:27362913) (PS4). Functional studies show <10% of normal enzyme activity compared to wildtype (PMID:26179960) (PS3). Computational predictions support a deleterious effect on the gene or gene product (PP3). The variant has been reported in dbSNP (rs386833587) and in the HGMD database: CM042354. It has been reported as Pathogenic/Likely pathogenic by other diagnostic laboratories (ClinVar Variation ID: 56104).

not provided Pathogenic:4
Mar 18, 2022
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Published functional studies demonstrate that this variant leads to an unstable protein and reduced enzyme activity (Swanson et al., 2015); Not observed at a significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 15272469, 26179960, 16601880, 16450403, 27362913)

Genome Diagnostics Laboratory, University Medical Center Utrecht
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

Genome Diagnostics Laboratory, Amsterdam University Medical Center
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

Glycine encephalopathy 1 Pathogenic:2
Aug 16, 2017
Counsyl
Significance:Likely pathogenic
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.

Dec 20, 2023
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.45
BayesDel_addAF
Pathogenic
0.42
D
BayesDel_noAF
Pathogenic
0.55
CADD
Pathogenic
30
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.83
D;.
Eigen
Pathogenic
0.94
Eigen_PC
Pathogenic
0.88
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Pathogenic
0.98
D;D
M_CAP
Pathogenic
0.32
D
MetaRNN
Pathogenic
0.98
D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.7
H;.
PhyloP100
7.5
PrimateAI
Uncertain
0.73
T
PROVEAN
Pathogenic
-5.3
D;.
REVEL
Pathogenic
0.94
Sift
Pathogenic
0.0
D;.
Sift4G
Uncertain
0.026
D;.
Vest4
0.91
ClinPred
0.99
D
GERP RS
5.5
PromoterAI
0.027
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.93
gMVP
0.91
Mutation Taster
=9/91
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs386833587; hg19: chr9-6605186; API