14-87988493-C-T

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PP2PP3_Moderate

The NM_000153.4(GALC):c.226G>A(p.Glu76Lys) variant causes a missense change. The variant allele was found at a frequency of 0.0000323 in 1,611,322 control chromosomes in the GnomAD database, including 1 homozygotes. 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. E76E) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000040 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000032 ( 1 hom. )

Consequence

GALC
NM_000153.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 5.61

Variant links:

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]

GALC links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000153.4

PM2

Very rare variant in population databases, with high coverage;

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 94 curated pathogenic missense variants (we use a threshold of 10). The gene has 16 curated benign missense variants. Gene score misZ: 0.18582 (below the threshold of 3.09). Trascript score misZ: -0.28853 (below the threshold of 3.09). GenCC associations: The gene is linked to Krabbe disease.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.855

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GALC	NM_000153.4 link	c.226G>A	p.Glu76Lys	missense_variant	Exon 2 of 17	ENST00000261304.7	NP_000144.2	P54803-1A0A0A0MQV0

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GALC	ENST00000261304.7 link	c.226G>A	p.Glu76Lys	missense_variant	Exon 2 of 17	1	NM_000153.4	ENSP00000261304.2		P54803-1

Frequencies

GnomAD3 genomes

AF:

0.0000395

AC:

AN:

151850

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000656

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:

0.0000736

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000441

AC:

AN:

249172

AF XY:

0.0000444

show subpopulations

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000885

Gnomad OTH exome

AF:

0.000165

GnomAD4 exome

AF:

0.0000315

AC:

AN:

1459472

Hom.:

Cov.:

AF XY:

0.0000330

AC XY:

AN XY:

726280

show subpopulations

Gnomad4 AFR exome

AF:

0.00

AC:

AN:

33426

Gnomad4 AMR exome

AF:

0.00

AC:

AN:

44716

Gnomad4 ASJ exome

AF:

0.00

AC:

AN:

26118

Gnomad4 EAS exome

AF:

0.00

AC:

AN:

39672

Gnomad4 SAS exome

AF:

0.00

AC:

AN:

86198

Gnomad4 FIN exome

AF:

0.00

AC:

AN:

53404

Gnomad4 NFE exome

AF:

0.0000387

AC:

AN:

1109870

Gnomad4 Remaining exome

AF:

0.0000332

AC:

AN:

60314

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000395

AC:

AN:

151850

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74138

show subpopulations

Gnomad4 AFR

AF:

0.00

AC:

AN:

Gnomad4 AMR

AF:

0.0000656

AC:

0.0000655566

AN:

0.0000655566

Gnomad4 ASJ

AF:

0.00

AC:

AN:

Gnomad4 EAS

AF:

0.00

AC:

AN:

Gnomad4 SAS

AF:

0.00

AC:

AN:

Gnomad4 FIN

AF:

0.00

AC:

AN:

Gnomad4 NFE

AF:

0.0000736

AC:

0.000073551

AN:

0.000073551

Gnomad4 OTH

AF:

0.00

AC:

AN:

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000966

Hom.:

ExAC

AF:

0.0000579

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Galactosylceramide beta-galactosidase deficiency

Uncertain:4

Sep 16, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jun 30, 2022

MGZ Medical Genetics Center

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Aug 13, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 76 of the GALC protein (p.Glu76Lys). This variant is present in population databases (rs778447883, gnomAD 0.009%). This missense change has been observed in individual(s) with GALC-related conditions (PMID: 26795590). This variant is also known as p.Glu60Lys. ClinVar contains an entry for this variant (Variation ID: 381334). 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 with a positive predictive value of 95%. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on GALC function (PMID: 27638593). 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. -

not specified

Uncertain:1

Jan 23, 2024

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

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: GALC c.226G>A (p.Glu76Lys) results in a conservative amino acid change located in the glycosyl hydrolase family 59, catalytic domain (IPR049161) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4.4e-05 in 249172 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in GALC causing Krabbe Disease (4.4e-05 vs 0.0022), allowing no conclusion about variant significance. c.226G>A has been reported in the literature in 3 alleles from individuals who screened positive for Krabbe disease through a newborn screening program and were referred for confirmatory testing, although followup diagnostic testing information was only reported for one individual who was classified as low risk (Orsini_2016). This report does not provide unequivocal conclusions about association of the variant with Krabbe Disease. At least one publication reports experimental evidence evaluating an impact on protein function in vitro and found the variant results in approximately 75% of normal activity (Saavedra-Martiz_2016). The following publications have been ascertained in the context of this evaluation (PMID: 26795590, 27638593). ClinVar contains an entry for this variant (Variation ID: 381334). Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided

Uncertain:1

Nov 01, 2019

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Observed in 3 alleles among 348 infants with low GALC activity detected by New York state newborn screening; however, clinical and segregation information was not provided (Orsini et al., 2016); Published functional study showed E76K, reported as E60K using alternature nomenclature, displayed only a mild reduction in enzyme activity compared to wild type (Saavedra-Matiz et al., 2016); This variant is associated with the following publications: (PMID: 26795590, 27638593) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.24

BayesDel_addAF

Pathogenic

0.21

BayesDel_noAF

Pathogenic

0.26

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.84

D;.;.

Eigen

Uncertain

0.55

Eigen_PC

Uncertain

0.56

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.98

D;D;D

M_CAP

Pathogenic

0.47

MetaRNN

Pathogenic

0.86

D;D;D

MetaSVM

Pathogenic

0.84

MutationAssessor

Pathogenic

3.1

M;.;.

PrimateAI

Uncertain

0.74

PROVEAN

Uncertain

-3.3

D;D;D

REVEL

Pathogenic

0.79

Sift

Uncertain

0.0060

D;D;D

Sift4G

Uncertain

0.016

D;D;D

Polyphen

0.98

D;P;D

Vest4

0.90

MVP

0.97

MPC

0.19

ClinPred

0.85

GERP RS

4.8

Varity_R

0.62

gMVP

0.91

Mutation Taster

=10/90

disease causing

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over