rs1555934413

Variant names:

• chrX-19355530-G-A
• rs1555934413
• NM_000284.4:c.759+26G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_000284.4(PDHA1):​c.759+26G>A variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 18)
• Consequence: PDHA1 NM_000284.4 intron
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.598
• Publications: 0 publications found

Genes affected

PDHA1 (HGNC:8806): (pyruvate dehydrogenase E1 subunit alpha 1) The pyruvate dehydrogenase (PDH) complex is a nuclear-encoded mitochondrial multienzyme complex that catalyzes the overall conversion of pyruvate to acetyl-CoA and CO(2), and provides the primary link between glycolysis and the tricarboxylic acid (TCA) cycle. The PDH complex is composed of multiple copies of three enzymatic components: pyruvate dehydrogenase (E1), dihydrolipoamide acetyltransferase (E2) and lipoamide dehydrogenase (E3). The E1 enzyme is a heterotetramer of two alpha and two beta subunits. This gene encodes the E1 alpha 1 subunit containing the E1 active site, and plays a key role in the function of the PDH complex. Mutations in this gene are associated with pyruvate dehydrogenase E1-alpha deficiency and X-linked Leigh syndrome. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Mar 2010]

PDHA1 Gene-Disease associations (from GenCC):

• Leigh syndrome

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• pyruvate dehydrogenase E1-alpha deficiency

  Inheritance: XL, AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet, Ambry Genetics
• Leigh syndrome with leukodystrophy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PDHA1	NM_000284.4	c.759+26G>A		intron_variant	Intron 7 of 10	ENST00000422285.7	NP_000275.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PDHA1	ENST00000422285.7	c.759+26G>A		intron_variant	Intron 7 of 10	1	NM_000284.4	ENSP00000394382.2

Frequencies

GnomAD3 genomes Cov.: 18

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 18

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Pyruvate dehydrogenase E1-alpha deficiency Uncertain:1

Nov 23, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Experimental studies have shown that this intronic change leads to the activation of a cryptic in-frame donor splice site in intron 7 that would result in the inclusion of 15 aberrant amino acids into the PDHA1 protein (PMID: 12551913). This sequence change falls in intron 7 of the PDHA1 gene. It does not directly change the encoded amino acid sequence of the PDHA1 protein. This variant is not present in population databases (ExAC no frequency). This variant has been reported in an individual affected with lactic acidosis (PMID: 12551913). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.70
CADD	Benign	1.5
DANN	Benign	0.88
PhyloP100		0.60
PromoterAI		0.025	Neutral
Mutation Taster		=20/80	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.33		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.33		Position offset: -26

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

Other links and lift over

dbSNP: rs1555934413; hg19: chrX-19373648;