chr5-126595120-C-G

Position:

• chr5-126595120-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001182.5(ALDH7A1):​c.79G>C​(p.Ala27Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000028 in 1,428,958 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: ALDH7A1 NM_001182.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 2.36

Genes affected

ALDH7A1 (HGNC:877): (aldehyde dehydrogenase 7 family member A1) The protein encoded by this gene is a member of subfamily 7 in the aldehyde dehydrogenase gene family. These enzymes are thought to play a major role in the detoxification of aldehydes generated by alcohol metabolism and lipid peroxidation. This particular member has homology to a previously described protein from the green garden pea, the 26g pea turgor protein. It is also involved in lysine catabolism that is known to occur in the mitochondrial matrix. Recent reports show that this protein is found both in the cytosol and the mitochondria, and the two forms likely arise from the use of alternative translation initiation sites. An additional variant encoding a different isoform has also been found for this gene. Mutations in this gene are associated with pyridoxine-dependent epilepsy. Several related pseudogenes have also been identified. [provided by RefSeq, Jan 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ALDH7A1	NM_001182.5	c.79G>C	p.Ala27Pro	missense_variant	1/18	ENST00000409134.8	NP_001173.2
ALDH7A1	NM_001202404.2	c.79G>C	p.Ala27Pro	missense_variant	1/16		NP_001189333.2
ALDH7A1	NM_001201377.2	c.-6G>C		5_prime_UTR_variant	1/18		NP_001188306.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ALDH7A1	ENST00000409134.8	c.79G>C	p.Ala27Pro	missense_variant	1/18	1	NM_001182.5	ENSP00000387123	P4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000280 AC: 4 AN: 1428958 Hom.: 0 Cov.: 32 AF XY: 0.00000282 AC XY: 2 AN XY: 707986

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000365

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Pyridoxine-dependent epilepsy Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Apr 11, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 27, 2021	This sequence change replaces alanine with proline at codon 27 of the ALDH7A1 protein (p.Ala27Pro). The alanine residue is weakly conserved and there is a small physicochemical difference between alanine and proline. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with ALDH7A1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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. -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 09, 2022

The c.79G>C (p.A27P) alteration is located in exon 1 (coding exon 1) of the ALDH7A1 gene. This alteration results from a G to C substitution at nucleotide position 79, causing the alanine (A) at amino acid position 27 to be replaced by a proline (P). 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	Benign	0.11
BayesDel_addAF	Uncertain	0.16	D
BayesDel_noAF	Uncertain	-0.010
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Benign	0.023	T;T;T;.;T;.;.;.;T;T;T;T
Eigen	Benign	0.019
Eigen_PC	Benign	0.17
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.93	D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Uncertain	0.51	D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	-0.11	T
MutationAssessor	Benign	1.6	.;L;.;.;.;.;.;L;.;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.49	T
PROVEAN	Benign	-0.64	.;N;.;.;.;.;.;N;.;.;N;N
REVEL	Uncertain	0.40
Sift	Uncertain	0.026	.;D;.;.;.;.;.;T;.;.;D;T
Sift4G	Benign	0.062	.;T;.;.;.;.;.;T;.;T;.;.
Polyphen		0.0020	.;B;.;.;.;.;.;.;.;.;.;.
Vest4		0.27, 0.28, 0.34
MutPred		0.52		Gain of sheet (P = 0.0266);Gain of sheet (P = 0.0266);Gain of sheet (P = 0.0266);Gain of sheet (P = 0.0266);Gain of sheet (P = 0.0266);Gain of sheet (P = 0.0266);Gain of sheet (P = 0.0266);Gain of sheet (P = 0.0266);Gain of sheet (P = 0.0266);Gain of sheet (P = 0.0266);.;Gain of sheet (P = 0.0266);
MVP		0.89
MPC		0.20
ClinPred		0.85	D
GERP RS		5.0
Varity_R		0.33
gMVP		0.75

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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

Other links and lift over

dbSNP: rs1060502950; hg19: chr5-125930812;