The Tazy or Kazakh National sighthound has been officially recognized as the national heritage of Kazakhstan. Comprehensive genetic studies of genetic diversity and population structure that could be used for selection and conservation of this unique dog breed have not been conducted so far. The aim of this study was to determine the genetic structure of the Tazy using microsatellite and SNP markers and to place the breed in the context of the world sighthound breeds. Our results showed that all 19 microsatellite loci examined were polymorphic. The observed number of alleles in the Tazy population varied from 6 (INU030 locus) to 12 (AHT137, REN169D01, AHTh260, AHT121, and FH2054 loci) with a mean of 9.778 alleles per locus. The mean number of effective alleles was 4.869 and ranged from 3.349 f to 4.841. All markers were highly informative (PIC values greater than 0.5) and ranged from 0.543 (REN247M23 locus) to 0.865 (AHT121 locus). The observed and expected heterozygosities in a total population were 0.748 and 0.769 and ranged from 0.746 to 0.750 and 0.656 to 0.769, respectively. Overall, the results confirmed that the Tazy breed has a high level of genetic diversity, no significant inbreeding, and a specific genetic structure. Three gene pools underlie the genetic diversity of the Tazy breed. SNP analysis using the CanineHD SNP array, which contains more than 170,000 SNP markers, showed that the Tazy breed is distinct from other sighthound breeds and genetically related to ancient eastern sighthound breeds sharing the same branch with the Afghan Hound and the Saluki. The results, together with archeological findings, confirm the ancient origin of the breed. The findings can be used for the conservation and international registration of the Tazy dog breed.
The Tazy is a breed of sighthound common in Kazakhstan. The identification of runs of homozygosity (ROH) is an informative approach to assessing the history and possible patterns of directional selection pressure. To our knowledge, the present study is the first to provide an overview of the ROH pattern in the Tazy dogs from a genome-wide perspective. The ROH of the Tazy was found to be mainly composed of shorter segments (1–2 Mb), accounting for approximately 67% of the total ROH. The estimated ROH-based inbreeding coefficients (FROH) ranged from 0.028 to 0.058 with a mean of 0.057. Five genomic regions under positive selection were identified on chromosomes 18, 22, and 25. The regions on chromosomes 18 and 22 may be breed specific, while the region on chromosome 22 overlaps with regions of hunting traits in other hunting dog breeds. Among the 12 candidate genes located in these regions, the gene CAB39L may be a candidate that affects running speed and endurance of the Tazy dog. Eight genes could belong to an evolutionarily conserved complex as they were clustered in a large protein network with strong linkages. The results may enable effective interventions when incorporated into conservation planning and selection of the Tazy breed.
Autism spectrum disorders (ASDs) are heterogeneous diseases that are triggered by a number of environmental and genetic factors. The aim of the current study was to investigate an association of the rs1799836 genetic variant of the neurotransmitter-related gene MAOB with ASDs. In total, 262 patients diagnosed with ASDs and their 126 healthy siblings were included in the present study. All individuals represented a Kazakhstani population. The distributions of the rs1799836 genotype were in accordance with the Hardy-Weinberg equilibrium among both cases and controls. No statistically significant differences were found in the allelic distributions of this polymorphism between ASD and control subjects (A/G: for males , 95% 0.59-2.06, ; for females , 95% 0.70-1.86, ). However, the increased score in the overall CARS was significantly associated with the A allele of rs1799836 MAOB for females (, 95% 1.06-5.04, ). The obtained results suggest that the rs1799836 polymorphism of the MAOB gene may have little contribution to the development of ASDs but may be involved in pathways contributing to ASD symptom severity in females. Further large-scale investigations are required to uncover possible relationships between rs1799836 MAOB and ASD progression in a gender-specific manner and their possible application as a therapeutic target.
The study of extended pedigrees containing autism spectrum disorder- (ASD-) related broader autism phenotypes (BAP) offers a promising approach to the search for ASD candidate variants. Here, a total of 650,000 genetic markers were tested in four Kazakhstani multiplex families with ASD and BAP to obtain data on de novo mutations (DNMs), common, and rare inherited variants that may contribute to the genetic risk for developing autistic traits. The variants were analyzed in the context of gene networks and pathways. Several previously well-described enriched pathways were identified, including ion channel activity, regulation of synaptic function, and membrane depolarization. Perhaps these pathways are crucial not only for the development of ASD but also for . The results also point to several additional biological pathways (circadian entrainment, NCAM and BTN family interactions, and interaction between L1 and Ankyrins) and hub genes (CFTR, NOD2, PPP2R2B, and TTR). The obtained results suggest that further exploration of PPI networks combining ASD and BAP risk genes can be used to identify novel or overlooked ASD molecular mechanisms.
The Kazakh Tobet is an indigenous Kazakh dog breed that has been used to guard livestock since ancient times. To understand the genetic structure and phylogenetic relationship of the Kazakh Tobet breed with other herding and livestock guarding dog breeds, we analysed short tandem repeat data of 107 Kazakh Tobet dogs from different regions of Kazakhstan and Mongolia, as well as whole genome sequencing data from two Kazakh Tobet dogs and 43 dogs from 24 working breeds. Our results indicate a high genetic diversity of the Kazakh Tobet, with the average number of alleles per locus ranging from 6.00 to 10.22 and observed heterozygosity ranging from 76 to 78%. The breed has a complex genetic structure characterised by seven different clusters. The neighbour-joining tree constructed based on 14,668,406 autosomal and the maximum likelihood tree based on mitochondrial D-loop sequences indicate a common genetic heritage between the Kazakh Tobet, the Central Asian Shepherd Dog and the Turkish Akbash. The presence of haplotype A18 in the Kazakh Tobets supports the hypothesis of the ancient origin of the breed, which was previously suggested by archaeological finds and written sources. These results provide an important genetic basis for the ongoing efforts to improve the Kazakh Tobet breed, to ensure its preservation as an independent genetic lineage and to recognise a breed on an international level.
16 August 2024 in Orphanet Journal of Rare Diseases
Background: Chromosome 7 has regions enriched with low copy repeats (LCRs), which increase the likelihood of chromosomal microdeletion disorders. Documented microdeletion disorders on chromosome 7 include both well-known Williams syndrome and more rare cases. It is noteworthy that most cases of various microdeletions are characterized by phenotypic signs of neuropsychological developmental disorders, which, however, have a different genetic origin. The localization of the microdeletions, the genes included in the region, as well as the structural features of the sequences of these genes have a cumulative influence on the phenotypic characteristics of the individuals for each specific case and the severity of the manifestations of disorders. The consideration of these features and their detailed analysis is important for a correct and comprehensive assessment of the disease. Results: The article describes a clinical case of 7p22.3 microdeletion in a patient with congenital heart defect and neurological abnormalities - epilepsy, combined with moderate mental and motor developmental delay. Conclusions: Through detailed genetic analyses, we are improving the clinical description of the rare 7p22.3 microdeletion and thus creating a basis for future genetic counseling and research into targeted therapies.