Background and Goal. The aim was to examine the serum levels of homocysteine (Hcy) and their associations with the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism in patients with schizophrenia and mood disorders as well as controls. Materials and Methods. There were 198 patients: 82 with schizophrenia spectrum disorders, 22 with mood disorders, and 94 controls. The level of Hcy was determined by an isocratic high-performance liquid chromatography system. MTHFR C677T polymorphism was analysed using the restriction fragment length polymorphism-polymerase chain reaction method. Results. The average level of Hcy was 11.94 ± 5.6 μmol/L for patients with schizophrenia, 11.65 ± 3.3 μmol/L for patients with affective disorders, versus 6.80 ± 2.93 μmol/L in a control. The highest level of Hcy has been observed in patients with episodic-recurrent course of schizophrenia (11.30 ± 7.74 μmol/L), paranoid schizophrenia continuous (12.76 ± 5.25 μmol/L), and in patients with affective disorders (11.65 ± 3.26 μmol/L). An association between the MTHFR gene C677T polymorphism and Hcy level was found by linear regression analysis (r = 1.41, P = 0.029). Conclusions. The data indicate a link between Hcy levels and schizophrenia and mood disorders. No associations between the level of Hcy in patients with schizophrenia and mood disorders and the MTHFR C677T polymorphism were found.

The level of Hcy is higher in the blood of a heterozygotic person who becomes ill with schizophrenia, and the process of the illness is more serious and with more typical affective disorders.

Autism spectrum disorders are early childhood neurodevelopmental disorders, it is not a disease but rather a syndrome that is characterized by a multifactorial type of inheritance and a rapid annual increase in prevalence.In some cases autism spectrum disorders are one of the symptoms of monogenic or chromosomal pathology, and can also be a symptom of inherited metabolic disorders. A reconstruction of human mitochondrial metabolic network has been used to model insufficiency of some genes encoded proteins to observe the consequences at metabolic network scale and propose approaches for the development of diagnostics. Flux variability analysis of mitochondrial metabolic network reconstruction is performed maximizing ATP production. It is found that deletion of SUCLG2 gene reduces the maximal production of ATP by 50% with wide flux variability range for most of reactions. Deletion of gene SLC25A12 reduces the maximal ATP production just by 1% but the new state is very fragile as most of reactions have very narrow flux variability range and any disturbance would cause reduction of ATP production that can not be compensated by other reactions. Detection of insufficiency of genes SUCLG2 and SLC25A12 is

Several genetic loci in chromosomes 11 and 15 have recently been associated with non-syndromic autism spectrum disorder (ASD) in populations from North America and Europe. The aim of the present study was to investigate whether such an association exists in a Latvian population. Ninety-five patients with ASD in the age range 3–20 years (mean age 8 years, SD 3.18) participated in the study. The control group consisted of 161 healthy, non-related individuals without ASD randomly selected from the Latvian Genome Database. Four single nucleotide polymorphisms (SNPs) — rs11212733, SNP rs1394119, rs2421826, rs1454985 — were genotyped by the TaqMan method. Allele frequency differences between ASD patients and control subjects were compared for each SNP using a standard chi-square test with Bonferroni correction. The level of statistical significance was set at 0.05 for nominal association. Only the genetic marker rs11212733, localised on the long arm of chromosome 11 in locus 22.3, was found to be strongly associated with the ASD patient group (χ2 6.982, Padjusted 0.033, odds ratio 1.625). Our data demonstrating a significant relationship between the SNP rs11212733 and the development of ASD in a Latvian population suggest that it is not a population-specific relationship. Thus, future studies focusing on the DDX10 gene and related genetic loci are needed.