Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_ModerateBP6BP7
The NM_006279.5(ST3GAL3):c.990C>T(p.Asn330Asn) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000109 in 1,461,862 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]
Verdict is Likely_benign. Variant got -2 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.41).
BP6
Variant 1-43920880-C-T is Benign according to our data. Variant chr1-43920880-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 212313.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.
BP7
Synonymous conserved (PhyloP=-2.57 with no splicing effect.
Genetic Services Laboratory, University of Chicago
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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ST3GAL3-related disorder Benign:1
Apr 12, 2019
PreventionGenetics, part of Exact Sciences
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing
This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -
Early infantile epileptic encephalopathy with suppression bursts Benign:1
Mar 04, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter