9-6588403-C-T

Variant summary

Our verdict is Benign. Variant got -16 ACMG points: 0P and 16B. BP4_StrongBP6_Very_StrongBS2

The NM_000170.3(GLDC):​c.1705G>A​(p.Ala569Thr) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00492 in 1,609,056 control chromosomes in the GnomAD database, including 42 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0040 ( 1 hom., cov: 32)
Exomes 𝑓: 0.0050 ( 41 hom. )

Consequence

GLDC
NM_000170.3 missense, splice_region

Scores

4
14
Splicing: ADA: 0.00002804
2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts P:1U:1B:11

Conservation

PhyloP100: 0.438
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]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -16 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.014870584).
BP6
Variant 9-6588403-C-T is Benign according to our data. Variant chr9-6588403-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 235431.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr9-6588403-C-T is described in Lovd as [Benign]. Variant chr9-6588403-C-T is described in Lovd as [Likely_benign]. Variant chr9-6588403-C-T is described in Lovd as [Likely_pathogenic].
BS2
High Homozygotes in GnomAdExome4 at 41 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
GLDCNM_000170.3 linkuse as main transcriptc.1705G>A p.Ala569Thr missense_variant, splice_region_variant 14/25 ENST00000321612.8 NP_000161.2 P23378

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
GLDCENST00000321612.8 linkuse as main transcriptc.1705G>A p.Ala569Thr missense_variant, splice_region_variant 14/251 NM_000170.3 ENSP00000370737.4 P23378

Frequencies

GnomAD3 genomes
AF:
0.00396
AC:
603
AN:
152082
Hom.:
1
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00113
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00255
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.0176
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00478
Gnomad OTH
AF:
0.00287
GnomAD3 exomes
AF:
0.00430
AC:
1081
AN:
251442
Hom.:
8
AF XY:
0.00407
AC XY:
553
AN XY:
135882
show subpopulations
Gnomad AFR exome
AF:
0.000615
Gnomad AMR exome
AF:
0.00153
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0187
Gnomad NFE exome
AF:
0.00514
Gnomad OTH exome
AF:
0.00489
GnomAD4 exome
AF:
0.00502
AC:
7318
AN:
1456856
Hom.:
41
Cov.:
29
AF XY:
0.00478
AC XY:
3469
AN XY:
725202
show subpopulations
Gnomad4 AFR exome
AF:
0.000719
Gnomad4 AMR exome
AF:
0.00141
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.0198
Gnomad4 NFE exome
AF:
0.00537
Gnomad4 OTH exome
AF:
0.00380
GnomAD4 genome
AF:
0.00396
AC:
603
AN:
152200
Hom.:
1
Cov.:
32
AF XY:
0.00439
AC XY:
327
AN XY:
74408
show subpopulations
Gnomad4 AFR
AF:
0.00113
Gnomad4 AMR
AF:
0.00255
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.0176
Gnomad4 NFE
AF:
0.00478
Gnomad4 OTH
AF:
0.00284
Alfa
AF:
0.00372
Hom.:
2
Bravo
AF:
0.00274
TwinsUK
AF:
0.00863
AC:
32
ALSPAC
AF:
0.00441
AC:
17
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00558
AC:
48
ExAC
AF:
0.00390
AC:
474
EpiCase
AF:
0.00425
EpiControl
AF:
0.00445

ClinVar

Significance: Benign/Likely benign
Submissions summary: Pathogenic:1Uncertain:1Benign:11
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Glycine encephalopathy Pathogenic:1Uncertain:1Benign:4
Benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpFeb 01, 2024- -
Likely benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaApr 27, 2017This 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). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to determine this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -
Benign, no assertion criteria providedclinical testingDiagnostic Laboratory, Department of Genetics, University Medical Center Groningen-- -
Likely benign, criteria provided, single submitterclinical testingInstitute of Human Genetics, University of Leipzig Medical CenterJan 01, 2019- -
Likely pathogenic, flagged submissionclinical testingKnight Diagnostic Laboratories, Oregon Health and Sciences UniversityMar 30, 2016The c.1705G>A (p.Ala569Thr) missense variant in the GLDC gene is known and has been previously reported in at least 7 individuals affected with Glycine encephalopathy (Kure et al., 2006; Narisawa et al., 2012; Swanson et al., 2015). This variant has often been described in trans with another pathogenic variant (Pro765Ser, Pro304Leu) (Kure et al., 2006; Swanson et al., 2015). Multiple in vitro functional assays have demonstrated this variant results in reduced or undetectable GLDC activity (Narisawa et al., 2012; Swanson et al., 2015). This variant is reported at low frequency in the population databases (Exome Sequencing Project = 0.558%; 1000 Genomes = 0.7%; and ExAC = 0.454%). Therefore, this collective evidence supports the classification of the c.1705G>A (p.Ala569Thr) as a recessive Likely pathogenic variant for Glycine encephalopathy. We have confirmed this finding in our laboratory using Sanger sequencing. -
Uncertain significance, flagged submissionclinical testingNatera, Inc.Oct 09, 2019- -
not provided Benign:6
Likely benign, no assertion criteria providedclinical testingLaboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)-- -
Likely benign, no assertion criteria providedclinical testingGenome Diagnostics Laboratory, University Medical Center Utrecht-- -
Likely benign, criteria provided, single submitterclinical testingCenter for Pediatric Genomic Medicine, Children's Mercy Hospital and ClinicsApr 12, 2016- -
Likely benign, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenAug 01, 2024GLDC: BS2 -
Benign, criteria provided, single submitterclinical testingGeneDxJul 04, 2018This variant is associated with the following publications: (PMID: 26179960, 22171071, 16450403, 27362913) -
Benign, criteria provided, single submitterclinical testingAthena DiagnosticsSep 20, 2017- -
not specified Benign:1
Benign, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpJun 27, 2022Variant summary: GLDC c.1705G>A (p.Ala569Thr) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0043 in 252282 control chromosomes in the gnomAD database, including 8 homozygotes. The observed variant frequency is approximately 2-fold of the estimated maximal expected allele frequency for a pathogenic variant in GLDC causing Glycine Encephalopathy (Non-Ketotic Hyperglycinemia) phenotype (0.0031), strongly suggesting that the variant is benign. c.1705G>A has been reported in the literature in individuals affected with Glycine Encephalopathy (Non-Ketotic Hyperglycinemia) without strong evidence for causality (e.g. Kure_2006, Narisawa_2012, Swanson_2015). Functional studies assessing the impact of the variant on protein function have reported 40-75% enzyme activity and normal protein levels (Swanson_2015, Narisawa_2012). Nine assessments for this variant have been submitted to ClinVar after 2014 with conflicting assessments (benign n=3, likely benign n=4, VUS n=1, likely pathogenic n=1). Based on the evidence outlined above, the variant was classified as benign. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.067
BayesDel_addAF
Benign
-0.14
T
BayesDel_noAF
Uncertain
0.030
CADD
Benign
8.7
DANN
Benign
0.94
DEOGEN2
Benign
0.25
T
Eigen
Benign
-1.0
Eigen_PC
Benign
-1.0
FATHMM_MKL
Benign
0.40
N
LIST_S2
Uncertain
0.86
D
MetaRNN
Benign
0.015
T
MetaSVM
Uncertain
0.011
D
MutationAssessor
Benign
0.64
N
PrimateAI
Benign
0.29
T
PROVEAN
Benign
-0.36
N
REVEL
Uncertain
0.58
Sift
Benign
0.085
T
Sift4G
Benign
0.083
T
Polyphen
0.0
B
Vest4
0.21
MVP
0.90
MPC
0.045
ClinPred
0.017
T
GERP RS
-4.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.099
gMVP
0.61

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.000028
dbscSNV1_RF
Benign
0.016
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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs151268759; hg19: chr9-6588403; API