Employment of single-strand conformation polymorphism analysis in screening for α-1,3 glucosyltransferase gene mutation A333V in Croatian population.

Congenital disorder of glycosylation type Ic (CDG-Ic) is caused by mutations in hALG6 gene encoding α-1,3 glucosyltransferase (NP_037471.2), an enzyme that catalyzes the addition of the first glucose residue to the growing lipid-linked oligosaccharide precursor in N-glycosylation process. The most frequent mutation in hALG6 gene causing CDG-Ic is c.998C>T that results in p.A333V substitution. Up-to-date, no CDG-Ic patient has been detected in Croatia. However, as a part of the comprehensive project undertaken with the aim to estimate the frequencies of the carriers for specific mutations and polymorphisms related to particular CDGs in Croatian population, we screened genomic DNA samples obtained from 600 healthy nonconsanguineous Croatian residents to determine the frequency of the A333V mutation. For that purpose, we established the conditions for polymerase chain reaction-based single-strand conformation polymorphism analysis that is suitable for primary screening and in population studies, especially when the initial sample volume is small or DNA quantity is limited. None of the analyzed samples carried this mutation, indicating that the frequency of the patients carrying this homozygous mutation in Croatian population would be <1 in 1.4×10(6).