Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2BP4
The NM_006279.5(ST3GAL3):c.80C>T(p.Ala27Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,870 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 (★). Synonymous variant affecting the same amino acid position (i.e. A27A) has been classified as Likely benign.
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]
Early infantile epileptic encephalopathy with suppression bursts Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Jul 05, 2020
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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with ST3GAL3-related conditions. This variant is present in population databases (rs751825349, ExAC 0.001%). This sequence change replaces alanine with valine at codon 27 of the ST3GAL3 protein (p.Ala27Val). The alanine residue is moderately conserved and there is a small physicochemical difference between alanine and valine. -
Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);Gain of methylation at K29 (P = 0.0829);.;.;