Familial hypercholesterolemia (FH) is an inherited metabolic disorder that increases cardiovascular risk from childhood. Despite its frequency, pediatric diagnosis and treatment remain limited, partic Show more
Familial hypercholesterolemia (FH) is an inherited metabolic disorder that increases cardiovascular risk from childhood. Despite its frequency, pediatric diagnosis and treatment remain limited, particularly in developing countries. Retrospective analysis of pediatric patients with genetically confirmed heterozygous FH (HeFH). Genetic testing included sequencing of the genes Among the cohort of 124 patients only 28.2% of patients were diagnosed via routine lipid screening, though 90.3% had a positive family history. After diagnosis, 16.1% declined treatment and 41.1% were lost to follow-up. Most genetic diagnoses involved pathogenic This is the first large pediatric HeFH cohort study from Türkiye and provides data on both genetic background and treatment outcome. Despite genetic confirmation, significant gaps remain in early diagnosis, treatment acceptance, and long-term follow-up. Both atorvastatin and pitavastatin proved to be safe and effective. These results suggest a need for national screening programmes, family education, dietary counselling, and consistent follow-up. Show less
Carbamoyl phosphate synthetase 1 (CPS1) deficiency due to CPS1 mutations is a rare autosomal-recessive urea cycle disorder causing hyperammonemia that can lead to death or severe neurological impairme Show more
Carbamoyl phosphate synthetase 1 (CPS1) deficiency due to CPS1 mutations is a rare autosomal-recessive urea cycle disorder causing hyperammonemia that can lead to death or severe neurological impairment. CPS1 catalyzes carbamoyl phosphate formation from ammonia, bicarbonate and two molecules of ATP, and requires the allosteric activator N-acetyl-L-glutamate. Clinical mutations occur in the entire CPS1 coding region, but mainly in single families, with little recurrence. We characterized here the only currently known recurrent CPS1 mutation, p.Val1013del, found in eleven unrelated patients of Turkish descent using recombinant His-tagged wild type or mutant CPS1 expressed in baculovirus/insect cell system. The global CPS1 reaction and the ATPase and ATP synthesis partial reactions that reflect, respectively, the bicarbonate and the carbamate phosphorylation steps, were assayed. We found that CPS1 wild type and V1013del mutant showed comparable expression levels and purity but the mutant CPS1 exhibited no significant residual activities. In the CPS1 structural model, V1013 belongs to a highly hydrophobic β-strand at the middle of the central β-sheet of the A subdomain of the carbamate phosphorylation domain and is close to the predicted carbamate tunnel that links both phosphorylation sites. Haplotype studies suggested that p.Val1013del is a founder mutation. In conclusion, the mutation p.V1013del inactivates CPS1 but does not render the enzyme grossly unstable or insoluble. Recurrence of this particular mutation in Turkish patients is likely due to a founder effect, which is consistent with the frequent consanguinity observed in the affected population. Show less