9-34649041-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.
The NM_000155.4(GALT):c.864C>T(p.Asn288Asn) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,613,992 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Consequence
NM_000155.4 synonymous
Scores
Clinical Significance
Conservation
Publications
- classic galactosemiaInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet
- galactosemiaInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, Myriad Women’s Health
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ACMG classification
Our verdict: Uncertain_significance. The variant received 0 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| GALT | ENST00000378842.8 | c.864C>T | p.Asn288Asn | synonymous_variant | Exon 9 of 11 | 1 | NM_000155.4 | ENSP00000368119.4 | ||
| ENSG00000258728 | ENST00000556278.1 | c.432+585C>T | intron_variant | Intron 4 of 7 | 5 | ENSP00000451792.1 |
Frequencies
GnomAD3 genomes AF: 0.0000920 AC: 14AN: 152118Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000437 AC: 11AN: 251492 AF XY: 0.0000441 show subpopulations
GnomAD4 exome AF: 0.0000192 AC: 28AN: 1461874Hom.: 0 Cov.: 32 AF XY: 0.0000261 AC XY: 19AN XY: 727232 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000920 AC: 14AN: 152118Hom.: 0 Cov.: 32 AF XY: 0.000108 AC XY: 8AN XY: 74306 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase Uncertain:3
This sequence change affects codon 288 of the GALT mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the GALT protein. This variant is present in population databases (rs372134800, gnomAD 0.03%). This variant has been observed in individual(s) with features of galactosemia (PMID: 22944367). ClinVar contains an entry for this variant (Variation ID: 203732). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
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This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
not specified Uncertain:2
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Variant summary: GALT c.864C>T alters a conserved nucleotide resulting in a synonymous change. Several computational tools predict a significant impact on normal splicing: One predict the variant strengthens a cryptic 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 4.4e-05 in 251692 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in GALT causing Galactosemia (4.4e-05 vs 0.0029), allowing no conclusion about variant significance. The variant, c.864C>T, has been reported in the literature in two compound heterozygous individuals affected with Galactosemia (McDonald_2009, Boutron_2012). One of these reports also noted that the diagnosis was confirmed by absent GALT activity in erythrocytes in all their cases, though no patient specific data were provided (Boutron 2012). The variant has also been reported in homozygosity in a sample from an individual that had only a residual GALT activity; and although no information was provided on the patient's phenotype, the measured enzyme activity was specific for galactosemia (Yuzyuk_2018). A conference abstract (McDonald 2009) described that cDNA containing the variant of interest (from a proband and probands father) was void of exon 9, although they both had additional variants leading to a complex haplotype (N288N, T292T and H315H) and it is not clear if the exon skipping effect was caused solely by our variant of interest or a combination effect due to this specific haplotype. These data indicate that the variant may be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 22944367, 33636947). ClinVar contains an entry for this variant (Variation ID: 203732). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -
Galactosemia Uncertain:1
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not provided Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at