rs121964979

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM1PM2PP3_ModeratePP5_Very_Strong

The NM_000170.3(GLDC):​c.1166C>T​(p.Ala389Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000156 in 1,605,198 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. A389A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

GLDC
NM_000170.3 missense

Scores

17
1
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:10

Conservation

PhyloP100: 9.13

Publications

12 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 14 ACMG points.

PM1
In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_000170.3
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.92
PP5
Variant 9-6595109-G-A is Pathogenic according to our data. Variant chr9-6595109-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 11989.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.1166C>T p.Ala389Val missense_variant Exon 9 of 25 ENST00000321612.8 NP_000161.2 P23378

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GLDCENST00000321612.8 linkc.1166C>T p.Ala389Val missense_variant Exon 9 of 25 1 NM_000170.3 ENSP00000370737.4 P23378

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152200
Hom.:
0
Cov.:
33
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:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000279
AC:
7
AN:
251148
AF XY:
0.0000221
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:
0.0000616
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000138
AC:
20
AN:
1452998
Hom.:
0
Cov.:
29
AF XY:
0.0000166
AC XY:
12
AN XY:
723598
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33272
American (AMR)
AF:
0.00
AC:
0
AN:
44712
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26082
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39670
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86054
European-Finnish (FIN)
AF:
0.0000188
AC:
1
AN:
53332
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5744
European-Non Finnish (NFE)
AF:
0.0000154
AC:
17
AN:
1104034
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60098
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.418
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000329
AC:
5
AN:
152200
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74360
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000588
AC:
4
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.545
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000676
Hom.:
2
Bravo
AF:
0.0000378
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000330
AC:
4

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:10
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Glycine encephalopathy Pathogenic:5
Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Across a selection of the available literature, the GLDC c.1166C>T (p.Ala389Val) variant has been identified 25 patients with glycine encephalopathy, including in a homozygous state in 11 patients and in a compound heterozygous state in 14 patients (Applegarth et al. 2004; Dinopoulos et al. 2005; Kure et al. 2006; Swanson et al. 2015; Coughlin et al. 2016). The variant has also been identified in four unaffected family members (Dinopoulos et al. 2005). The p.Ala389Val variant was absent from 300 controls and is reported at a frequency of 0.00006 in the European (non-Finnish) population of the Exome Aggregation Consortium. The Ala389 residue is conserved. Functional expression studies in COS-7 cells showed that the variant enzyme retained from 7.9% to over 10% of the wild type enzymatic activity which may explain the mild phenotype (Dinopoulos et al. 2005; Swanson et al. 2015). The Ala389 residue is highly conserved. Based on the collective evidence, the p. Ala389Val variant is classified as pathogenic for glycine encephalopathy. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -

Dec 27, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 389 of the GLDC protein (p.Ala389Val). This variant is present in population databases (rs121964979, gnomAD 0.008%). This missense change has been observed in individual(s) with glycine encephalopathy (PMID: 15824356, 16450403, 26179960, 26749113). 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: 11989). 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%. Experimental studies have shown that this missense change affects GLDC function (PMID: 15824356, 26179960). For these reasons, this variant has been classified as Pathogenic. -

May 16, 2019
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 20, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Mar 13, 2024
Rady Children's Institute for Genomic Medicine, Rady Children's Hospital San Diego
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1166C>T (p.Ala389Val) variant affects a highly conserved amino acid and is predicted by multiple in silico tools to have a deleterious effect on protein function. This variant has been previously reported as a compound heterozygous and homozygous change in individuals with glycine encephalopathy (PMID: 16450403, 26749113, 26179960, 32421718). Functional studies indicate this variant may lead to reduced enzyme activity (PMID: 26179960). The c.1166C>T (p.Ala389Val) variant is present in the heterozygous state in the gnomAD v4 population database at a frequency of 0.002% (25/1605198) and thus is presumed to be rare. Based on the available evidence, c.1166C>T (p.Ala389Val) is classified as Pathogenic. -

Glycine encephalopathy 1 Pathogenic:3
Oct 30, 2024
Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 12, 2005
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

May 09, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Pathogenic:1
May 07, 2024
Ambry Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1166C>T (p.A389V) alteration is located in exon 9 (coding exon 9) of the GLDC gene. This alteration results from a C to T substitution at nucleotide position 1166, causing the alanine (A) at amino acid position 389 to be replaced by a valine (V). Based on data from gnomAD, the T allele has an overall frequency of 0.003% (9/282552) total alleles studied. The highest observed frequency was 0.007% (9/128976) of European (non-Finnish) alleles. This variant has been identified in the homozygous state and/or in conjunction with other GLDC variant(s) in individual(s) with features consistent with autosomal recessive GLDC-related glycine encephalopathy; in at least one instance, the variants were identified in trans (Kure, 2006; Swanson, 2015; Dinopoulos, 2005). This amino acid position is highly conserved in available vertebrate species. This alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, this alteration is classified as pathogenic. -

not provided Pathogenic:1
Apr 22, 2022
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Homozygous individuals in the literature (Applegarth et al., 2004; Dinopooulos et al., 2005) reported to have milder nonketotic hyperglycinemia phenotype or phenotypic variability; In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at a significant frequency in large population cohorts, and no individuals were reported to be homozygous (gnomAD); This variant is associated with the following publications: (PMID: 26179960, 26749113, 15824356, 15272469, 32421718, 27362913, 16450403) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.93
BayesDel_addAF
Pathogenic
0.44
D
BayesDel_noAF
Pathogenic
0.58
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.82
D;.
Eigen
Pathogenic
0.97
Eigen_PC
Pathogenic
0.88
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
1.0
D;D
M_CAP
Pathogenic
0.50
D
MetaRNN
Pathogenic
0.92
D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
2.9
M;.
PhyloP100
9.1
PrimateAI
Pathogenic
0.79
T
PROVEAN
Uncertain
-4.0
D;.
REVEL
Pathogenic
0.95
Sift
Pathogenic
0.0
D;.
Sift4G
Pathogenic
0.0
D;.
Polyphen
1.0
D;.
Vest4
0.95
MVP
1.0
MPC
0.32
ClinPred
0.97
D
GERP RS
4.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.97
gMVP
0.89
Mutation Taster
=8/92
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: rs121964979; hg19: chr9-6595109; COSMIC: COSV58678308; COSMIC: COSV58678308; API