X-101398386-C-T

Variant names:

• chrX-101398386-C-T
• rs28935492
• NM_000169.3:c.983G>A

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000169.3(GLA):​c.983G>A​(p.Gly328Glu) 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G328V) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 23)
• Consequence: GLA NM_000169.3 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.91
• Publications: 1 publications found

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

Our verdict: Pathogenic. The variant received 19 ACMG points.

• PM1: In a hotspot region, there are 18 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 19 uncertain in NM_000169.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrX-101398386-C-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 1324469.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 218 curated pathogenic missense variants (we use a threshold of 10). The gene has 17 curated benign missense variants. Gene score misZ: 1.8759 (below the threshold of 3.09). Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to Fabry disease.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.976
• PP5: Variant X-101398386-C-T is Pathogenic according to our data. Variant chrX-101398386-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 2138661.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GLA	NM_000169.3	c.983G>A	p.Gly328Glu	missense_variant	Exon 6 of 7	ENST00000218516.4	NP_000160.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GLA	ENST00000218516.4	c.983G>A	p.Gly328Glu	missense_variant	Exon 6 of 7	1	NM_000169.3	ENSP00000218516.4
RPL36A-HNRNPH2	ENST00000409170.3	c.300+2929C>T		intron_variant	Intron 4 of 4	4		ENSP00000386655.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 23

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Fabry disease Pathogenic:2

Jun 26, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.Gly328 amino acid residue in GLA. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 7504405, 16595074, 27834756). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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 disruptive. This missense change has been observed in individual(s) with clinical features of Fabry disease (Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 328 of the GLA protein (p.Gly328Glu). -

Apr 19, 2023

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: GLA c.983G>A (p.Gly328Glu) results in a non-conservative amino acid change located in the C-terminal beta-sandwich domain (IPR035373) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 183458 control chromosomes (gnomAD). c.983G>A has been reported in the literature in at least one hemizygous male and two heterozygous females affected with Fabry Disease (e.g. Germain_2010, Germain_2015, Echevarria_2015). These data indicate that the variant may be associated with disease. One of these publications reported the complete absence of detectable alpha-galactosidase activity in plasma from a hemizygous male (Germain_2015). One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as likely pathogenic. Additionally, missense variants impacting the same amino acid, p.G328R/A/V, have been reported in association with Fabry disease (HGMD). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
CardioboostCm	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.82
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	D;.
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D;D
M_CAP	Pathogenic	0.98	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Pathogenic	4.7	H;.
PhyloP100		7.9
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-7.8	D;.
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;.
Sift4G	Pathogenic	0.0	D;.
Polyphen		1.0	D;.
Vest4		0.99
MutPred		0.78		Gain of solvent accessibility (P = 0.0411);.;
MVP		1.0
MPC		2.0
ClinPred		1.0	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.99
gMVP		1.0
Mutation Taster		=0/100	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

dbSNP: rs28935492; hg19: chrX-100653374;