rs786204635

Positions:

• chr14-87976452-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000153.4(GALC):​c.658C>T​(p.Arg220Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000822 in 1,460,512 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 Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: GALC NM_000153.4 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: 0.419

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 Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 14-87976452-G-A is Pathogenic according to our data. Variant chr14-87976452-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 189024.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GALC	NM_000153.4	c.658C>T	p.Arg220Ter	stop_gained	7/17	ENST00000261304.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GALC	ENST00000261304.7	c.658C>T	p.Arg220Ter	stop_gained	7/17	1	NM_000153.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000822 AC: 12 AN: 1460512 Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3 AN XY: 726750

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000900

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000828 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Galactosylceramide beta-galactosidase deficiency Pathogenic:4

Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Oct 20, 2014	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 31, 2024	This sequence change creates a premature translational stop signal (p.Arg220*) in the GALC gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GALC are known to be pathogenic (PMID: 7437911, 9272171, 16607461). 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 premature translational stop signal has been observed in individuals with Krabbe disease (PMID: 16607461, 24252386). This variant is also known as R204X. ClinVar contains an entry for this variant (Variation ID: 189024). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Genomic Research Center, Shahid Beheshti University of Medical Sciences	Jul 20, 2024	This patient was heterozygous of two known very rare variants, c.1630G>A and c.658C>T, in the GALC gene. The c.658C>T variant is predicted to result in premature protein termination (p.Arg220Ter). These variants have been reported for their pathogenicity in ClinVar. Both variants were segregated within the family using Sanger sequencing. -

not provided Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Aug 12, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratoire de Génétique Moléculaire, CHU Bordeaux	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Mar 26, 2024	Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25525159, 31589614, 16607461, 27638593, 24252386, 36380532, 37928748, 37432431, 37434390, 34765479) -
Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Aug 31, 2017	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.30
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Uncertain	0.54
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Benign	0.24	N
MutationTaster	Benign	1.0	A;A;A;A
Vest4		0.93
GERP RS		4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs766310671; hg19: chr14-88442796; COSMIC: COSV99729746; COSMIC: COSV99729746;