chrX-101400667-T-G

Variant names:

• chrX-101400667-T-G
• rs869312149
• NM_000169.3:c.638A>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP2

The NM_000169.3(GLA):​c.638A>C​(p.Lys213Thr) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K213N) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 23)
• Consequence: GLA NM_000169.3 missense, splice_region
• Scores: Splicing: ADA: 0.8399
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.36
• Publications: 0 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: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 21 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 23 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-101400666-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 4087445.Status of the report is criteria_provided_single_submitter, 1 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GLA	NM_000169.3	c.638A>C	p.Lys213Thr	missense_variant, splice_region_variant	Exon 4 of 7	ENST00000218516.4	NP_000160.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GLA	ENST00000218516.4	c.638A>C	p.Lys213Thr	missense_variant, splice_region_variant	Exon 4 of 7	1	NM_000169.3	ENSP00000218516.4
RPL36A-HNRNPH2	ENST00000409170.3	c.300+5210T>G		intron_variant	Intron 4 of 4	4		ENSP00000386655.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 20

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Fabry disease Uncertain:1

Aug 26, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals affected with GLA-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. This variant is not present in population databases (ExAC no frequency). This sequence change replaces lysine with threonine at codon 213 of the GLA protein (p.Lys213Thr). The lysine residue is moderately conserved and there is a moderate physicochemical difference between lysine and threonine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
CardioboostCm	Benign	0.029
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.050
CADD	Uncertain	23
DANN	Uncertain	0.98
DEOGEN2	Pathogenic	0.85	D;.
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.85	T;D
M_CAP	Pathogenic	0.99	D
MetaRNN	Uncertain	0.57	D;D
MetaSVM	Pathogenic	1.3	D
MutationAssessor	Benign	1.6	L;.
PhyloP100		5.4
PrimateAI	Benign	0.43	T
PROVEAN	Uncertain	-3.7	D;.
REVEL	Uncertain	0.55
Sift	Benign	0.16	T;.
Sift4G	Benign	0.14	T;.
Polyphen		0.44	B;.
Vest4		0.42
MutPred		0.46		Loss of methylation at K213 (P = 0.0067);.;
MVP		0.87
MPC		1.4
ClinPred		0.88	D
GERP RS		5.4
Varity_R		0.68
gMVP		0.94
Mutation Taster		=54/46	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.84
dbscSNV1_RF	Benign	0.68
SpliceAI score (max)		0.43		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.43		Position offset: -1

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

Other links and lift over

dbSNP: rs869312149; hg19: chrX-100655655;