chr9-34648131-G-A

Variant names:

• chr9-34648131-G-A
• rs111033718
• NM_000155.4:c.524G>A

Variant summary

Our verdict is Pathogenic. The variant received 21 ACMG points: 21P and 0B. PS3 PM1 PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_000155.4(GALT):​c.524G>A​(p.Gly175Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,880 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV000695695: The variant results in an almost complete loss of enzymatic activity (Coelho_2014). PMID:17486650, PMID:17041746, PMID:22944367, PMID:23749220, PMID:25614870, PMID:25814382".

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GALT NM_000155.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 8.40
• Publications: 9 publications found

Genes affected

GALT (HGNC:4135): (galactose-1-phosphate uridylyltransferase) Galactose-1-phosphate uridyl transferase (GALT) catalyzes the second step of the Leloir pathway of galactose metabolism, namely the conversion of UDP-glucose + galactose-1-phosphate to glucose-1-phosphate + UDP-galactose. The absence of this enzyme results in classic galactosemia in humans and can be fatal in the newborn period if lactose is not removed from the diet. The pathophysiology of galactosemia has not been clearly defined. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Apr 2012]

GALT Gene-Disease associations (from GenCC):

• classic galactosemia

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae)
• galactosemia

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, Myriad Women’s Health

ENSG00000258728 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 21 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV000695695: The variant results in an almost complete loss of enzymatic activity (Coelho_2014). PMID:17486650, PMID:17041746, PMID:22944367, PMID:23749220, PMID:25614870, PMID:25814382
• PM1: In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 uncertain in NM_000155.4
• 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 104 curated pathogenic missense variants (we use a threshold of 10). The gene has 17 curated benign missense variants. Gene score misZ: 0.91493 (below the threshold of 3.09). Trascript score misZ: 1.8645 (below the threshold of 3.09). GenCC associations: The gene is linked to galactosemia, classic galactosemia.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 9-34648131-G-A is Pathogenic according to our data. Variant chr9-34648131-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 25203.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000155.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GALT	NM_000155.4	MANE Select	c.524G>A	p.Gly175Asp	missense	Exon 6 of 11	NP_000146.2
	GALT	NM_001258332.2		c.197G>A	p.Gly66Asp	missense	Exon 4 of 9	NP_001245261.1	P07902-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GALT	ENST00000378842.8	TSL:1 MANE Select	c.524G>A	p.Gly175Asp	missense	Exon 6 of 11	ENSP00000368119.4	P07902-1
	ENSG00000258728	ENST00000556278.1	TSL:5	c.269G>A	p.Gly90Asp	missense	Exon 3 of 8	ENSP00000451792.1	G3V4G9
	GALT	ENST00000902340.1		c.563G>A	p.Gly188Asp	missense	Exon 5 of 10	ENSP00000572399.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461880 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727244

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112012

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
2	-	-	Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase (2)
1	-	-	Galactosemia (1)
1	-	-	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.62	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.9	H
PhyloP100		8.4
PrimateAI	Pathogenic	0.80	T
PROVEAN	Pathogenic	-6.9	D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.99		Gain of relative solvent accessibility (P = 0.09)
MVP		1.0
MPC		2.1
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.99
gMVP		1.0
Mutation Taster		=2/98	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.12		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: rs111033718; hg19: chr9-34648128;