[Epigenomic variations manifesting as a loss of heterozygosity affecting imprinted genes represent a molecular mechanism of autism spectrum disorders and intellectual disability in children].

Aim: Long continuous stretches of homozygosity (LCSH) are regularly detected in studies using molecular karyotyping (SNP array). Despite this type of variation being able to provide meaningful data on the parents' kinship, uniparental disomy and chromosome rearrangements, LCSH are rarely considered as a possible epigenetic cause of neurodevelopmental disorders. Despite their direct relationship to imprinting, LCSH in imprinted loci have not been considered in terms of pathogenicity.

[Structural variations of the genome in autistic spectrum disorders with intellectual disability].

Aim: To analyze structural variations in the genome in children with autism and intellectual disability.

Material And Methods: Using high-resolution karyotyping (AffymetrixCytoScan HD Array) and original bioinformatic technology, 200 children with autism and intellectual disability were studied.

Results And Conclusion: Data on structural variations in the genome in children with autism and intellectual disability are provided.

[Clinical and genetic characteristics of the X chromosome distal long arm microduplications encompassing the MECP2 gene].

Objective: Microduplications of the long arm of the X chromosome including the MECP2 gene are relatively common causes of neurodevelopmental disorders in males. Authors analyzed clinical presentations of this disease in children.

Material And Methods: Authors performed a clinical and genetic analysis of four cases using contemporary cytogenetic, molecular cytogenetic studies (FISH, array CGH) and X chromosome inactivation analysis.

[The use of molecular cytogenetic and cytogenetic techniques for the diagnosis of Prader-Willi and Angelman syndrome].

We examined 30 patients with a presumptive diagnosis of Prader-Willi and Angelman syndromes. In four patients, 15q11.2-q13 deletions were identified by cytogenetic techniques.

Cytogenetic, molecular-cytogenetic, and clinical-genealogical studies of the mothers of children with autism: a search for familial genetic markers for autistic disorders.

State-of-the-art cytogenetic and molecular-cytogenetic methods for studying human chromosomes were used to analyze chromosomal anomalies and variants in mothers of children with autistic disorders and the results were compared with clinical-genealogical data. These investigations showed that these mothers, as compared with a control group, showed increases in the frequencies of chromosomal anomalies (mainly mosaic forms involving chromosome X) and chromosomal heteromorphisms. Analysis of correlations of genotypes and phenotypes revealed increases in the frequencies of cognitive impairments and spontaneous abortions in the mothers of children with autism with chromosomal anomalies, as well as increases in the frequencies of mental retardation, death in childhood, and impairments to reproductive function in the pedigrees of these women.

Variability in the heterochromatin regions of the chromosomes and chromosomal anomalies in children with autism: identification of genetic markers of autistic spectrum disorders.

Cytogenetic and molecular cytogenetic analysis of children with autism (90 subjects) and their mothers (18 subjects) is presented. Anomalies and fragility were found in chromosome X in four cases of autism: mos 47,XXX[98]/46, XX[2]; 46,XY,r(22)(p11q13); 46,XY,inv(2)(p11.2q13),16qh-; and 46,Y,fra(X)(q27.

Two new cases of the Christchurch (Ch1) chromosome 21: evidence for clinical consequences of de novo deletion 21P-.

We performed an investigation of two unrelated cases with extremal variants of chromosome 21 without visible materials of the short arms (Christchurch or Ch1 chromosome). In the first case chromosome 21p- was initially detected during routine cytogenetic amniocentesis. Chromosomal variant was inherited from phenotypically normal father to phenotypically normal fetus (phenotypically normal boy after the birth).

5HTR2A gene polymorphism and personality traits in patients with major psychoses.

Serotonin receptor (5HTR2A) gene polymorphism has been reported to be associated with clinical phenotypes in schizophrenia. The current study attempted to investigate a relationship between 5HTR2A 102T/C polymorphism and personality traits as well as clinical symptoms in patients with ICD-10 diagnoses of schizophrenia and affective disorders. 5HTR2A genotyping, clinical and psychological assessment were administered to 375 patients, 104 first-degree healthy relatives of the patients and 157 controls.