NM_000170.3:c.270G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate

The NM_000170.3(GLDC):​c.270G>C​(p.Leu90Phe) variant causes a missense change. The variant allele was found at a frequency of 0.0000819 in 1,611,616 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L90M) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000085 ( 0 hom. )

Consequence

GLDC
NM_000170.3 missense

Scores

7
7
5

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 3.98

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 13 uncertain in NM_000170.3
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.88

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GLDCNM_000170.3 linkc.270G>C p.Leu90Phe missense_variant Exon 2 of 25 ENST00000321612.8 NP_000161.2 P23378

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GLDCENST00000321612.8 linkc.270G>C p.Leu90Phe missense_variant Exon 2 of 25 1 NM_000170.3 ENSP00000370737.4 P23378

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152196
Hom.:
0
Cov.:
31
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:
0.000118
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000836
AC:
21
AN:
251298
AF XY:
0.000110
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000465
Gnomad NFE exome
AF:
0.000158
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000850
AC:
124
AN:
1459302
Hom.:
0
Cov.:
29
AF XY:
0.0000991
AC XY:
72
AN XY:
726178
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33424
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26118
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39684
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86222
European-Finnish (FIN)
AF:
0.0000375
AC:
2
AN:
53294
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.000103
AC:
114
AN:
1109764
Other (OTH)
AF:
0.0000995
AC:
6
AN:
60310
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.457
Heterozygous variant carriers
0
7
15
22
30
37
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:
0.0000525
AC:
8
AN:
152314
Hom.:
0
Cov.:
31
AF XY:
0.0000134
AC XY:
1
AN XY:
74490
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41564
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000118
AC:
8
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
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:
0.000113
Hom.:
0
Bravo
AF:
0.0000604
ExAC
AF:
0.0000576
AC:
7
EpiCase
AF:
0.000218
EpiControl
AF:
0.000119

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Glycine encephalopathy Uncertain:3
Nov 11, 2019
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Aug 08, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 90 of the GLDC protein (p.Leu90Phe). This variant is present in population databases (rs747736821, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with GLDC-related conditions. ClinVar contains an entry for this variant (Variation ID: 531775). 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. 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. -

Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

not provided Uncertain:2
Mar 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

GLDC: PM2 -

Dec 03, 2019
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Inborn genetic diseases Uncertain:1
Jul 09, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.270G>C (p.L90F) alteration is located in exon 2 (coding exon 2) of the GLDC gene. This alteration results from a G to C substitution at nucleotide position 270, causing the leucine (L) at amino acid position 90 to be replaced by a phenylalanine (F). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.54
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Pathogenic
0.31
CADD
Benign
23
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.72
D
Eigen
Benign
0.11
Eigen_PC
Benign
0.16
FATHMM_MKL
Uncertain
0.84
D
LIST_S2
Pathogenic
1.0
D
M_CAP
Pathogenic
0.34
D
MetaRNN
Pathogenic
0.88
D
MetaSVM
Pathogenic
0.93
D
MutationAssessor
Uncertain
2.1
M
PhyloP100
4.0
PrimateAI
Uncertain
0.65
T
PROVEAN
Uncertain
-3.4
D
REVEL
Pathogenic
0.81
Sift
Benign
0.076
T
Sift4G
Benign
0.22
T
Polyphen
0.25
B
Vest4
0.78
MutPred
0.85
Gain of methylation at K93 (P = 0.1086);
MVP
0.99
MPC
0.30
ClinPred
0.24
T
GERP RS
3.8
Varity_R
0.71
gMVP
0.87
Mutation Taster
=3/97
disease causing

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: rs747736821; hg19: chr9-6644678; API