9-6556159-A-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.2196T>A(p.Asn732Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 151,874 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. N732N) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

GLDC
NM_000170.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:2

Conservation

PhyloP100: 0.0740

Publications

4 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 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 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, 0.96

PP5

Variant 9-6556159-A-T is Pathogenic according to our data. Variant chr9-6556159-A-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 56063.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GLDC	NM_000170.3 link	c.2196T>A	p.Asn732Lys	missense_variant	Exon 18 of 25	ENST00000321612.8	NP_000161.2	P23378

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GLDC	ENST00000321612.8 link	c.2196T>A	p.Asn732Lys	missense_variant	Exon 18 of 25	1	NM_000170.3	ENSP00000370737.4		P23378

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

151874

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000656

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.00000658

AC:

AN:

151874

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74174

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41304

American (AMR)

AF:

0.0000656

AC:

AN:

15252

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5170

South Asian (SAS)

AF:

0.00

AC:

AN:

4812

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10574

Middle Eastern (MID)

AF:

0.00

AC:

AN:

314

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67980

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000302

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:4Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Glycine encephalopathy

Pathogenic:2Uncertain:1

Feb 19, 2021

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Feb 11, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces asparagine, which is neutral and polar, with lysine, which is basic and polar, at codon 732 of the GLDC protein (p.Asn732Lys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with nonketotic hyperglycinemia (PMID: 16601880). 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: 56063). 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 with a positive predictive value of 80%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)

Significance:Likely pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

Glycine encephalopathy 1

Pathogenic:2

Jan 09, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Aug 30, 2023

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

ACMG classification criteria: PM2 moderate, PM3 strong, PP3 supporting -

Inborn genetic diseases

Uncertain:1

Feb 14, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.2196T>A (p.N732K) alteration is located in exon 18 (coding exon 18) of the GLDC gene. This alteration results from a T to A substitution at nucleotide position 2196, causing the asparagine (N) at amino acid position 732 to be replaced by a lysine (K). 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

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.22

BayesDel_noAF

Uncertain

0.080

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.87

D;.;.

Eigen

Benign

0.088

Eigen_PC

Benign

-0.12

FATHMM_MKL

Uncertain

0.78

LIST_S2

Pathogenic

0.99

D;D;D

M_CAP

Pathogenic

0.79

MetaRNN

Pathogenic

0.96

D;D;D

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

4.2

H;.;.

PhyloP100

0.074

PrimateAI

Pathogenic

0.86

PROVEAN

Pathogenic

-5.8

D;.;.

REVEL

Pathogenic

0.87

Sift

Pathogenic

0.0

D;.;.

Sift4G

Pathogenic

0.0

D;.;.

Polyphen

1.0

D;.;.

Vest4

0.99

MutPred

0.82

Gain of ubiquitination at N732 (P = 0.0369);.;.;

MVP

0.99

MPC

0.32

ClinPred

1.0

GERP RS

-2.2

Varity_R

0.94

gMVP

0.97

Mutation Taster

=3/97

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

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over