chrX-55009259-A-G

Variant names:

• chrX-55009259-A-G
• NM_000032.5:c.1685T>C

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_000032.5(ALAS2):​c.1685T>C​(p.Val562Ala) 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. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: ALAS2 NM_000032.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.32
• Publications: 1 publications found

Genes affected

ALAS2 (HGNC:397): (5'-aminolevulinate synthase 2) The product of this gene specifies an erythroid-specific mitochondrially located enzyme. The encoded protein catalyzes the first step in the heme biosynthetic pathway. Defects in this gene cause X-linked pyridoxine-responsive sideroblastic anemia. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]

APEX2 (HGNC:17889): (apurinic/apyrimidinic endodeoxyribonuclease 2) Apurinic/apyrimidinic (AP) sites occur frequently in DNA molecules by spontaneous hydrolysis, by DNA damaging agents or by DNA glycosylases that remove specific abnormal bases. AP sites are pre-mutagenic lesions that can prevent normal DNA replication so the cell contains systems to identify and repair such sites. Class II AP endonucleases cleave the phosphodiester backbone 5' to the AP site. This gene encodes a protein shown to have a weak class II AP endonuclease activity. Most of the encoded protein is located in the nucleus but some is also present in mitochondria. This protein may play an important role in both nuclear and mitochondrial base excision repair. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Nov 2012]

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 4 uncertain in NM_000032.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.78

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000032.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ALAS2	NM_000032.5	MANE Select	c.1685T>C	p.Val562Ala	missense	Exon 11 of 11	NP_000023.2	P22557-1
	ALAS2	NM_001037968.4		c.1646T>C	p.Val549Ala	missense	Exon 11 of 11	NP_001033057.1	P22557-4
	ALAS2	NM_001037967.4		c.1574T>C	p.Val525Ala	missense	Exon 10 of 10	NP_001033056.1	P22557-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ALAS2	ENST00000650242.1	MANE Select	c.1685T>C	p.Val562Ala	missense	Exon 11 of 11	ENSP00000497236.1	P22557-1
	ALAS2	ENST00000396198.7	TSL:5	c.1646T>C	p.Val549Ala	missense	Exon 11 of 11	ENSP00000379501.3	P22557-4
	ALAS2	ENST00000335854.8	TSL:2	c.1574T>C	p.Val525Ala	missense	Exon 10 of 10	ENSP00000337131.4	P22557-2

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 23

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	2	-	not provided (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.30
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Benign	0.32	T
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Benign	0.86	D
M_CAP	Pathogenic	0.82	D
MetaRNN	Pathogenic	0.78	D
MetaSVM	Uncertain	0.70	D
MutationAssessor	Benign	1.1	L
PhyloP100		9.3
PrimateAI	Benign	0.48	T
PROVEAN	Benign	-2.1	N
REVEL	Pathogenic	0.69
Sift	Uncertain	0.0050	D
Sift4G	Uncertain	0.010	D
Polyphen		0.55	P
Vest4		0.51
MutPred		0.41		Loss of catalytic residue at V562 (P = 0.0233)
MVP		1.0
MPC		0.74
ClinPred		0.88	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.69
gMVP		0.67
Mutation Taster		=4/96	disease causing

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

hg19: chrX-55035692;