9-34648765-C-T
Variant summary
Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong
The NM_000155.4(GALT):c.691C>T(p.Arg231Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000411 in 1,461,050 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 (★★).
Frequency
Consequence
NM_000155.4 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Pathogenic. Variant got 14 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD3 exomes AF: 0.00000798 AC: 2AN: 250552Hom.: 0 AF XY: 0.00000738 AC XY: 1AN XY: 135488
GnomAD4 exome AF: 0.00000411 AC: 6AN: 1461050Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4AN XY: 726898
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase Pathogenic:5
- -
This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 231 of the GALT protein (p.Arg231Cys). This variant is present in population databases (rs111033749, gnomAD 0.01%). This missense change has been observed in individual(s) with low GALT enzyme activity, findings that are highly specific for galactose-1-phosphate uridylyltransferase deficiency (PMID: 14518827, 22944367; internal data). ClinVar contains an entry for this variant (Variation ID: 25246). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt GALT protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects GALT function (PMID: 25614870, 25814382). This variant disrupts the p.Arg231 amino acid residue in GALT. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 7550229, 11152465, 22944367, 25614870). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
- -
- -
Variant summary: The GALT c.691C>T (p.Arg231Cys) variant involves the alteration of a conserved nucleotide and is located in the intersubunit interface of the protein (Boutron_2012). 4/4 in silico tools predict a damaging outcome for this variant. This variant has been reported multiple patients with galactosemia in homozygous or compound heterozygous state with other pathogenic variants (Alfadhel_2016, Boutron_2012, Schadewaldt_2003) and is absent in 121210 control chromosomes. A functional study showed this variant leads to loss of enzymatic activity (Coelho_2014). Another missense change (p.R231H) at this residue has also been reported in association with galactosemia (ARUP, ClinVar). Multiple clinical diagnostic laboratories/reputable databases have classified this variant as pathogenic. Taken together, this variant is classified as Pathogenic. -
not provided Pathogenic:2
Published functional studies found this variant is associated with significantly reduced enzyme activity (PMID: 25614870); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 27629047, 33636947, 36515074, 25614870, 22944367, 30718057, 25814382, 31980526, 31130284) -
- -
Galactosemia Pathogenic:1
- -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at