9-6554726-T-G

Variant names:

• chr9-6554726-T-G
• rs386833547
• NM_000170.3:c.2258A>C

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_000170.3(GLDC):​c.2258A>C​(p.His753Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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 Likely pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H753Q) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: GLDC NM_000170.3 missense
• Clinical Significance: Likely pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.65
• Publications: 3 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PM1: In a hotspot region, there are 7 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
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-6554725-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1382260.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 9-6554726-T-G is Pathogenic according to our data. Variant chr9-6554726-T-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 56066.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000170.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GLDC	NM_000170.3	MANE Select	c.2258A>C	p.His753Pro	missense	Exon 19 of 25	NP_000161.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GLDC	ENST00000321612.8	TSL:1 MANE Select	c.2258A>C	p.His753Pro	missense	Exon 19 of 25	ENSP00000370737.4
	GLDC	ENST00000638233.1	TSL:1	n.693A>C		non_coding_transcript_exon	Exon 5 of 11
	GLDC	ENST00000639443.1	TSL:1	n.1826A>C		non_coding_transcript_exon	Exon 15 of 21

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions as Germline

Significance: Likely pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	Glycine encephalopathy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	32
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.87	D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.83	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Pathogenic	4.5	H
PhyloP100		7.6
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-9.5	D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.96		Gain of ubiquitination at K754 (P = 0.0645)
MVP		1.0
MPC		0.38
ClinPred		1.0	D
GERP RS		5.4
PromoterAI		-0.013	Neutral
Varity_R		0.99
gMVP		0.99
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

Other links and lift over

dbSNP: rs386833547; hg19: chr9-6554726;