19-12899466-A-G

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1 PM2 PP3_Strong PP5_Very_Strong

The NM_000159.4(GCDH):c.1244-2A>G variant causes a splice acceptor 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: GCDH NM_000159.4 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 9.06

Genes affected

GCDH (HGNC:4189): (glutaryl-CoA dehydrogenase) The protein encoded by this gene belongs to the acyl-CoA dehydrogenase family. It catalyzes the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA and CO(2) in the degradative pathway of L-lysine, L-hydroxylysine, and L-tryptophan metabolism. It uses electron transfer flavoprotein as its electron acceptor. The enzyme exists in the mitochondrial matrix as a homotetramer of 45-kD subunits. Mutations in this gene result in the metabolic disorder glutaric aciduria type 1, which is also known as glutaric acidemia type I. Alternative splicing of this gene results in multiple transcript variants. A related pseudogene has been identified on chromosome 12. [provided by RefSeq, Mar 2013]

SYCE2 (HGNC:27411): (synaptonemal complex central element protein 2) The protein encoded by this gene is part of the synaptonemal complex formed between homologous chromosomes during meiotic prophase. The encoded protein associates with SYCP1 and SYCE1 and is found only where chromosome cores are synapsed. [provided by RefSeq, Dec 2012]

ACMG classification

Verdict is Pathogenic. Variant got 22 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 19-12899466-A-G is Pathogenic according to our data. Variant chr19-12899466-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 552962.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-12899466-A-G is described in Lovd as [Pathogenic]. Variant chr19-12899466-A-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GCDH	NM_000159.4	c.1244-2A>G		splice_acceptor_variant		ENST00000222214.10
SYCE2	NM_001105578.2	c.613-81T>C		intron_variant		ENST00000293695.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GCDH	ENST00000222214.10	c.1244-2A>G		splice_acceptor_variant		1	NM_000159.4	P1
SYCE2	ENST00000293695.8	c.613-81T>C		intron_variant		1	NM_001105578.2	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Glutaric aciduria, type 1 Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Oct 05, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Mar 24, 2021	Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. For these reasons, this variant has been classified as Pathogenic. Disruption of this splice site has been observed in individual(s) with glutaric acidemia type I (PMID: 25256449, 27672653). ClinVar contains an entry for this variant (Variation ID: 552962). This variant is not present in population databases (ExAC no frequency). This sequence change affects an acceptor splice site in intron 11 of the GCDH gene. While this variant is not anticipated to result in nonsense mediated decay, it likely alters RNA splicing and results in a disrupted protein product. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Jul 31, 2017	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.37
Cadd	Pathogenic	31
Dann	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D;D;D;D;D
GERP RS		5.3

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.91		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.91		Position offset: 2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs199999619; hg19: chr19-13010280;