NM_000155.4:c.619C>T
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000155.4(GALT):c.619C>T(p.Gln207*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,888 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. Q207Q) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_000155.4 stop_gained
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: Pathogenic. The variant received 18 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.0000159 AC: 4AN: 251484 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.00000274 AC: 4AN: 1461888Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1AN XY: 727246 show subpopulations
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase Pathogenic:5
The GALT c.619C>T; p.Gln207Ter variant (rs111033743) is reported in the literature in multiple individuals affected with classic galactosemia, often found in cis with a Duarte variant (Carney 2009, Yang 2002). This variant is also reported in ClinVar (Variation ID: 25230). This variant is found in the Latino population with an allele frequency of 0.012% (4/34,590 alleles) in the Genome Aggregation Database. This variant induces an early termination codon and is predicted to result in a truncated protein or mRNA subject to nonsense-mediated decay. Based on available information, this variant is considered to be pathogenic. References: Carney AE et al. Origins, distribution and expression of the Duarte-2 (D2) allele of galactose-1-phosphate uridylyltransferase. Hum Mol Genet. 2009 May 1;18(9):1624-32. PMID: 19224951. Yang YP et al. Molecular analysis in newborns from Texas affected with galactosemia. Hum Mutat. 2002 Jan;19(1):82-3. PMID: 11754113. -
Variant summary: GALT c.619C>T (p.Gln207X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 1.6e-05 in 251584 control chromosomes. c.619C>T has been reported in the literature in individuals affected with Galactosemia (Yang_2002, Carney_2009, Lopez-Uriarte_2021). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
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This sequence change creates a premature translational stop signal (p.Gln207*) in the GALT gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GALT are known to be pathogenic (PMID: 22944367). This variant is present in population databases (rs111033743, gnomAD 0.01%). This premature translational stop signal has been observed in individual(s) with galactosemia (PMID: 11754113, 19224951). ClinVar contains an entry for this variant (Variation ID: 25230). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
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 provided Pathogenic:2
PP4, PM2_moderate, PVS1 -
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at