rs111033636

chr9-34646786-G-Achr9-34646786-G-Cchr9-34646786-G-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000155.4(GALT):c.82G>A(p.Asp28Asn) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,148 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D28H) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GALT NM_000155.4 missense, splice_region
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: 1.69

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]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000155.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GALT	NM_000155.4	c.82G>A	p.Asp28Asn	missense_variant, splice_region_variant	1/11	ENST00000378842.8
GALT	NM_001258332.2	c.-121G>A		splice_region_variant, 5_prime_UTR_variant	1/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GALT	ENST00000378842.8	c.82G>A	p.Asp28Asn	missense_variant, splice_region_variant	1/11	1	NM_000155.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461148 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 726914

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

Submissions by phenotype

Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

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

Oct 02, 2015

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Uncertain	0.028	T
BayesDel_noAF	Benign	-0.20
Cadd	Pathogenic	33
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	D;.
Eigen	Benign	0.0092
Eigen_PC	Benign	0.15
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.91	D;D
M_CAP	Pathogenic	0.29	D
MetaRNN	Pathogenic	0.81	D;D
MetaSVM	Pathogenic	0.97	D
MutationAssessor	Benign	1.3	L;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.54	T
PROVEAN	Uncertain	-2.7	D;N
REVEL	Uncertain	0.57
Sift	Benign	0.044	D;D
Sift4G	Benign	0.12	T;T
Polyphen		0.044	B;.
Vest4		0.26
MutPred		0.94		Gain of MoRF binding (P = 0.0741);Gain of MoRF binding (P = 0.0741);
MVP		0.98
MPC		0.84
ClinPred		0.98	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.52
gMVP		0.82

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.84		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.84		Position offset: 0

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs111033636; hg19: chr9-34646783;