9-34649462-C-G

Variant names:

• chr9-34649462-C-G
• rs111033792
• NM_000155.4:c.957C>G

Variant summary

Our verdict is Pathogenic. The variant received 25 ACMG points: 25P and 0B. PS1_Very_Strong PM1 PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_000155.4(GALT):​c.957C>G​(p.His319Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,866 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 (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Synonymous variant affecting the same amino acid position (i.e. H319H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GALT NM_000155.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: -0.291
• Publications: 12 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 25 ACMG points.

• PS1: Transcript NM_000155.4 (GALT) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 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, 0.994
• PP5: Variant 9-34649462-C-G is Pathogenic according to our data. Variant chr9-34649462-C-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 1324452.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.957C>G	p.His319Gln	missense	Exon 10 of 11	NP_000146.2
	GALT	NM_001258332.2		c.630C>G	p.His210Gln	missense	Exon 8 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.957C>G	p.His319Gln	missense	Exon 10 of 11	ENSP00000368119.4	P07902-1
	ENSG00000258728	ENST00000556278.1	TSL:5	c.432+1006C>G		intron	N/A	ENSP00000451792.1	G3V4G9
	GALT	ENST00000902340.1		c.996C>G	p.His332Gln	missense	Exon 9 of 10	ENSP00000572399.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251456 AF XY: 0.00000736

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: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461866 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727238

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

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: 53402

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112004

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 31

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
3	-	-	Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase (3)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Benign	18
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.96	D
Eigen	Benign	0.084
Eigen_PC	Benign	-0.12
FATHMM_MKL	Uncertain	0.77	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.89	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.0	H
PhyloP100		-0.29
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-7.8	D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.89
MutPred		0.98		Loss of helix (P = 0.1299)
MVP		0.98
MPC		0.33
ClinPred		1.0	D
GERP RS		-2.3
Varity_R		0.98
gMVP		0.95
Mutation Taster		=7/93	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs111033792; hg19: chr9-34649459;