X-101398789-T-G

Variant names:

• chrX-101398789-T-G
• rs28935487
• NM_000169.3:c.797A>C

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM2 PM5 PP3_Strong PP5

The NM_000169.3(GLA):​c.797A>C​(p.Asp266Ala) 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D266H) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 23)
• Consequence: GLA NM_000169.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 8.02

Genes affected

GLA (HGNC:4296): (galactosidase alpha) This gene encodes a homodimeric glycoprotein that hydrolyses the terminal alpha-galactosyl moieties from glycolipids and glycoproteins. This enzyme predominantly hydrolyzes ceramide trihexoside, and it can catalyze the hydrolysis of melibiose into galactose and glucose. A variety of mutations in this gene affect the synthesis, processing, and stability of this enzyme, which causes Fabry disease, a rare lysosomal storage disorder that results from a failure to catabolize alpha-D-galactosyl glycolipid moieties. [provided by RefSeq, Jul 2008]

RPL36A-HNRNPH2 (HGNC:48349): (RPL36A-HNRNPH2 readthrough) This locus represents naturally occurring read-through transcription between the neighboring ribosomal protein L36a and heterogeneous nuclear ribonucleoprotein H2 (H') genes on chromosome X. The read-through transcript produces a protein with similarity to the protein encoded by the upstream locus, ribosomal protein L36a. Alternatively spliced transcript variants have been identified. [provided by RefSeq, Jan 2011]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994
• PP5: Variant X-101398789-T-G is Pathogenic according to our data. Variant chrX-101398789-T-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 228701.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GLA	NM_000169.3	c.797A>C	p.Asp266Ala	missense_variant	Exon 5 of 7	ENST00000218516.4	NP_000160.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GLA	ENST00000218516.4	c.797A>C	p.Asp266Ala	missense_variant	Exon 5 of 7	1	NM_000169.3	ENSP00000218516.4
RPL36A-HNRNPH2	ENST00000409170.3	c.300+3332T>G		intron_variant	Intron 4 of 4	4		ENSP00000386655.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 23

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Fabry disease Pathogenic:1

Feb 24, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: GLA c.797A>C (p.Asp266Ala) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 183472 control chromosomes (gnomAD). c.797A>C has been reported in the literature in individuals affected with Fabry Disease (Militaru_20). Additionally, no residual enzymatic activity detected in a male individual carrying the variant (Militaru_2019). These data indicate that the variant is very likely to be associated with disease. A different variant affecting the same codon has been classified as pathogenic by our lab (c.797A>T, p.Asp266Val), supporting the critical relevance of codon 266 to GLA protein function. The following publications have been ascertained in the context of this evaluation (PMID: 32042454, 31475953). ClinVar contains an entry for this variant (Variation ID: 228701). Based on the evidence outlined above, the variant was classified as pathogenic. -

not specified Uncertain:1

Mar 11, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant classified as Uncertain Significance - Favor Pathogenic. The p.Asp266Ala variant in GLA has been previously reported in 1 Chinese individual with Fabry disease (Tian 2013) and was absent from large population studies. In addition, 5 different variants at this position (p.Asp266Val, p.Asp266His, p.Asp266Asn; p.A sp266Glu and p.Asp266Tyr) have been reported in at least 5 individuals with Fabr y disease (Eng 1993, Ashton-Prolla 2000, Lee 2000, Germain 2002, Erdos 2008), ra ising the possibility that a change at this position may not be tolerated. Compu tational prediction tools and evolutionary conservation analysis also suggest th at this variant may impact the protein, though this information is not predictiv e enough to determine pathogenicity. In summary, while there is some suspicion f or a pathogenic role, the clinical significance of the p.Asp266Ala variant is un certain. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
CardioboostCm	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.82
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	1.0	D;.
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	1.0	D;D
M_CAP	Pathogenic	0.97	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Pathogenic	4.7	H;.
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-7.9	D;.
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D;.
Sift4G	Pathogenic	0.0	D;.
Polyphen		1.0	D;.
Vest4		1.0
MutPred		0.98		Loss of stability (P = 0.1258);.;
MVP		1.0
MPC		2.0
ClinPred		1.0	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.99
gMVP		1.0

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

Publications

LitVar

Other links and lift over

dbSNP: rs28935487; hg19: chrX-100653777;