14-87993008-G-A

Position:

• chr14-87993008-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_000153.4(GALC):​c.157C>T​(p.Arg53Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000104 in 1,540,776 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. R53R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000010 (0 hom.)
• Consequence: GALC NM_000153.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.66

Genes affected

GALC (HGNC:4115): (galactosylceramidase) This gene encodes a lysosomal protein which hydrolyzes the galactose ester bonds of galactosylceramide, galactosylsphingosine, lactosylceramide, and monogalactosyldiglyceride. Mutations in this gene have been associated with Krabbe disease, also known as globoid cell leukodystrophy. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000153.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.871

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GALC	NM_000153.4	c.157C>T	p.Arg53Trp	missense_variant	1/17	ENST00000261304.7
GALC	NM_001201401.2	c.157C>T	p.Arg53Trp	missense_variant	1/16
GALC	NM_001201402.2	c.117+375C>T		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GALC	ENST00000261304.7	c.157C>T	p.Arg53Trp	missense_variant	1/17	1	NM_000153.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152150 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000140 AC: 2 AN: 142732 Hom.: 0 AF XY: 0.0000251 AC XY: 2 AN XY: 79534

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000444

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000170

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000101 AC: 14 AN: 1388626 Hom.: 0 Cov.: 33 AF XY: 0.0000146 AC XY: 10 AN XY: 687026

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: 0.0000127

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000120

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152150 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74334

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000151

ExAC AF: 0.00000951 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Galactosylceramide beta-galactosidase deficiency Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	May 27, 2023	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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt GALC protein function. ClinVar contains an entry for this variant (Variation ID: 557770). This missense change has been observed in individual(s) with Krabbe disease (PMID: 21824559). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 53 of the GALC protein (p.Arg53Trp). -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Apr 06, 2018	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.24
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D;.
Eigen	Uncertain	0.57
Eigen_PC	Uncertain	0.46
FATHMM_MKL	Uncertain	0.76	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.42	D
MetaRNN	Pathogenic	0.87	D;D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Uncertain	2.9	M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.91	D
PROVEAN	Pathogenic	-5.0	D;D
REVEL	Pathogenic	0.81
Sift	Uncertain	0.0020	D;D
Sift4G	Uncertain	0.0050	D;D
Polyphen		1.0	D;.
Vest4		0.77
MutPred		0.63		Gain of catalytic residue at L51 (P = 0);Gain of catalytic residue at L51 (P = 0);
MVP		0.99
MPC		0.51
ClinPred		0.99	D
GERP RS		3.2
Varity_R		0.63
gMVP		0.91

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs752371343; hg19: chr14-88459352;