Our verdict is Benign. Variant got -8 ACMG points: 2P and 10B. PM2BP4_StrongBP6BP7BS1
The NM_006279.5(ST3GAL3):c.840C>T(p.Ala280Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000743 in 1,614,044 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 Conflicting classifications of pathogenicity (no stars).
ST3GAL3 (HGNC:10866): (ST3 beta-galactoside alpha-2,3-sialyltransferase 3) The protein encoded by this gene is a type II membrane protein that catalyzes the transfer of sialic acid from CMP-sialic acid to galactose-containing substrates. The encoded protein is normally found in the Golgi apparatus but can be proteolytically processed to a soluble form. This protein is a member of glycosyltransferase family 29. Mutations in this gene have been associated with a form of autosomal recessive nonsymdromic cognitive disability as well as infantile epileptic encephalopathy. Multiple transcript variants encoding several different isoforms have been found for this gene. [provided by RefSeq, Jul 2017]
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.54).
BP6
Variant 1-43920499-C-T is Benign according to our data. Variant chr1-43920499-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 212311.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=1}.
BP7
Synonymous conserved (PhyloP=-3.16 with no splicing effect.
BS1
Variant frequency is greater than expected in population sas. gnomad4_exome allele frequency = 0.0000807 (118/1461892) while in subpopulation SAS AF= 0.000754 (65/86258). AF 95% confidence interval is 0.000606. There are 0 homozygotes in gnomad4_exome. There are 81 alleles in male gnomad4_exome subpopulation. Median coverage is 32. This position pass quality control queck.
Genetic Services Laboratory, University of Chicago
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Inborn genetic diseases Benign:1
May 01, 2018
Ambry Genetics
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Early infantile epileptic encephalopathy with suppression bursts Benign:1
May 31, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter