A rare neurodegenerative disorder with a novel mutation in ROGDI and Rett- like phenotype: Kohlschutter- Tönz syndrome

Kohlschutter-Tonz syndrome (KTZS) is a rare neurodegenerative disorder that presents with seizures, developmental delay, psychomotor regression, hypoplastic dental enamel morphology characteristic for amelogenesis imperfecta, and dysmorphologies. Genetic analysis has identified loss of function mutations within the coding region of the ROGDI and SLC13A5 genes in KTZS. In this report, we documented the clinical, radiological, electroencephalographic, and genetic results of a 3.5-year-old Turkish girl, born to nonconsanguineous parents, who was the first patient diagnosed with KTZS in Turkey. The patient presented with Rett syndrome-like phenotype, neurodevelopmental delay, refractory seizures, and amelogenesis imperfecta. After obtaining informed consent, chromosomal DNA was extracted from the peripheral blood of our patient and her parents. To investigate the molecular diagnosis of the patient, the clinical exome sequencing was performed. The Sanger sequencing analysis was performed for all of the family members for the validation and segregation of this mutation. Pub Med/Medline, Web of Science, and Google Scholar were also searched to find all of the published data on KTZS. The literature comprises 18 published studies about KTZS. The genetic analysis of our patient revealed a novel homozygous c.201-1G>T mutation in the ROGDI gene. The same mutation was also found to be heterozygous in her mother and father. The mutation caused alternative splicing of the ROGDI translation and resulted in a disruption of the ROGDI protein

Prevalence of DDC genotypes in patients with aromatic L-amino acid decarboxylase (AADC) deficiency and in silico prediction of structural protein changes

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive genetic disorder affecting the biosynthesis of dopamine, a precursor of both norepinephrine and epinephrine, and serotonin. Diagnosis is based on the analysis of CSF or plasma metabolites, AADC activity in plasma and genetic testing for variants in the DDC gene. The exact prevalence of AADC deficiency, the number of patients, and the variant and genotype prevalence are not known. Here, we present the DDC variant (n = 143) and genotype (n = 151) prevalence of 348 patients with AADC deficiency, 121 of whom were previously not reported. In addition, we report 26 new DDC variants, classify them according to the ACMG/AMP/ACGS recommendations for pathogenicity and score them based on the predicted structural effect. The splice variant c.714+4A>T, with a founder effect in Taiwan and China, was the most common variant (allele frequency = 32.4%), and c.[714+4A>T];[714+4A>T] was the most common genotype (genotype frequency = 21.3%). Approximately 90% of genotypes had variants classified as pathogenic or likely pathogenic, while 7% had one VUS allele and 3% had two VUS alleles. Only one benign variant was reported. Homozygous and compound heterozygous genotypes were interpreted in terms of AADC protein and categorized as: i) devoid of full-length AADC, ii) bearing one type of AADC homodimeric variant or iii) producing an AADC protein population composed of two homodimeric and one heterodimeric variant. Based on structural features, a score was attributed for all homodimers, and a tentative prediction was advanced for the heterodimer. Almost all AADC protein variants were pathogenic or likely pathogenic

Prevalence of DDC genotypes in patients with aromatic L-amino acid decarboxylase (AADC) deficiency and in silico prediction of structural protein changes

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive genetic disorder affecting the biosynthesis of dopamine, a precursor of both norepinephrine and epinephrine, and serotonin. Diagnosis is based on the analysis of CSF or plasma metabolites, AADC activity in plasma and genetic testing for variants in the DDC gene. The exact prevalence of AADC deficiency, the number of patients, and the variant and genotype prevalence are not known. Here, we present the DDC variant (n = 143) and genotype (n = 151) prevalence of 348 patients with AADC deficiency, 121 of whom were previously not reported. In addition, we report 26 new DDC variants, classify them according to the ACMG/AMP/ACGS recommendations for pathogenicity and score them based on the predicted structural effect. The splice variant c.714+4A>T, with a founder effect in Taiwan and China, was the most common variant (allele frequency = 32.4%), and c.[714+4A>T];[714+4A>T] was the most common genotype (genotype frequency = 21.3%). Approximately 90% of genotypes had variants classified as pathogenic or likely pathogenic, while 7% had one VUS allele and 3% had two VUS alleles. Only one benign variant was reported. Homozygous and compound heterozygous genotypes were interpreted in terms of AADC protein and categorized as: i) devoid of full-length AADC, ii) bearing one type of AADC homodimeric variant or iii) producing an AADC protein population composed of two homodimeric and one heterodimeric variant. Based on structural features, a score was attributed for all homodimers, and a tentative prediction was advanced for the heterodimer. Almost all AADC protein variants were pathogenic or likely pathogenic

Prevalence of DDC genotypes in patients with aromatic L-amino acid decarboxylase (AADC) deficiency and in silico prediction of structural protein changes

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive genetic disorder affecting the biosynthesis of dopamine, a precursor of both norepinephrine and epinephrine, and serotonin. Diagnosis is based on the analysis of CSF or plasma metabolites, AADC activity in plasma and genetic testing for variants in the DDC gene. The exact prevalence of AADC deficiency, the number of patients, and the variant and genotype prevalence are not known. Here, we present the DDC variant (n = 143) and genotype (n = 151) prevalence of 348 patients with AADC deficiency, 121 of whom were previously not reported. In addition, we report 26 new DDC variants, classify them according to the ACMG/AMP/ACGS recommendations for pathogenicity and score them based on the predicted structural effect. The splice variant c.714+4A>T, with a founder effect in Taiwan and China, was the most common variant (allele frequency = 32.4%), and c.[714+4A>T];[714+4A>T] was the most common genotype (genotype frequency = 21.3%). Approximately 90% of genotypes had variants classified as pathogenic or likely pathogenic, while 7% had one VUS allele and 3% had two VUS alleles. Only one benign variant was reported. Homozygous and compound heterozygous genotypes were interpreted in terms of AADC protein and categorized as: i) devoid of full-length AADC, ii) bearing one type of AADC homodimeric variant or iii) producing an AADC protein population composed of two homodimeric and one heterodimeric variant. Based on structural features, a score was attributed for all homodimers, and a tentative prediction was advanced for the heterodimer. Almost all AADC protein variants were pathogenic or likely pathogenic

Neuromuscular disease genetics in under-represented populations: increasing data diversity

Neuromuscular diseases (NMDs) affect ∼15 million people globally. In high income settings DNA-based diagnosis has transformed care pathways and led to gene-specific therapies. However, most affected families are in low-to-middle income countries (LMICs) with limited access to DNA-based diagnosis. Most (86%) published genetic data is derived from European ancestry. This marked genetic data inequality hampers understanding of genetic diversity and hinders accurate genetic diagnosis in all income settings. We developed a cloud-based transcontinental partnership to build diverse, deeply-phenotyped and genetically characterized cohorts to improve genetic architecture knowledge, and potentially advance diagnosis and clinical management. We connected 18 centres in Brazil, India, South Africa, Turkey, Zambia, Netherlands and the UK. We co-developed a cloud-based data solution and trained 17 international neurology fellows in clinical genomic data interpretation. Single gene and whole exome data were analysed via a bespoke bioinformatics pipeline and reviewed alongside clinical and phenotypic data in global webinars to inform genetic outcome decisions. We recruited 6001 participants in the first 43 months. Initial genetic analyses ‘solved’ or ‘possibly solved’ ∼56% probands overall. In-depth genetic data review of the four commonest clinical categories (limb girdle muscular dystrophy, inherited peripheral neuropathies, congenital myopathy/muscular dystrophies and Duchenne/Becker muscular dystrophy) delivered a ∼59% ‘solved’ and ∼13% ‘possibly solved’ outcome. Almost 29% of disease causing variants were novel, increasing diverse pathogenic variant knowledge. Unsolved participants represent a new discovery cohort. The dataset provides a large resource from under-represented populations for genetic and translational research. In conclusion, we established a remote transcontinental partnership to assess genetic architecture of NMDs across diverse populations. It supported DNA-based diagnosis, potentially enabling genetic counselling, care pathways and eligibility for gene-specific trials. Similar virtual partnerships could be adopted by other areas of global genomic neurological practice to reduce genetic data inequality and benefit patients globally

Investigation of sub-chromosomal changes in males with idiopathic azoospermia by chromosomal microarray analysis

Azoospermia consists of a significant proportion of infertility aetiology in males. Although known genetic abnormalities may explain roughly the third of infertility cases, the exact aetiology is still unclear. Chromosomal microarrays are widely used to detect sub chromosomal abnormalities (e.g., microdeletions and microduplications). This study aimed to investigate aetiology in patients with idiopathic azoospermia by using the chromosomal microarray method to detect possible sub chromosomal changes. Twenty-eight patients (with a mean age of 30.4 +/- 9 years) that had been diagnosed with idiopathic azoospermia between January 2019 and December 2020 were included in the study. Genomic DNA isolated from the blood of patients were amplified using polymerase chain reaction and was subjected to chromosomal microarray analysis. A total of six microdeletions were identified as clinically significant: one pathogenic copy number variation (CNV), four likely pathogenic CNVs, and one CNV of unknown clinical significance. However, clinical findings indicated that these microdeletions, with variable expression levels, may affect the spermatogenesis process and induce azoospermia. Future investigations regarding the functional effect of these deletions may contribute to our understanding of azoospermia aetiology

The Relationship Between Methylation Defects and Different Genetic Disorders: Two Case Reports

5, 10-methylenetetrahydrofolate reductase (MTHFR) is a coding gene, for a key enzyme in methionine-homocysteine and folate metabolism. This pathway has been associated with gene specific DNA hypo and hypermethylation as a result of gene switching on or off. Methylenetetrahydrofolate reductase C677T and A1298C gene polymorphisms are associated with folate metabolism disorders; such as, it results in an impaired DNA methylation and chromosomal abnormalities, gene deficiencies and structural anomalies. Here, we reported two cases of compound heterozygote and homozygote MTHFR gene mutation association with genetical disorders during the pregnancies

Determinación de los polimorfismos rs2058265, rs6464214 y rs7456421 de la proteína cinasa 2 que interactúan con el homeodominio en pacientes con cálculos renales

Objetivo: Investigar si el polimorfismo de la proteína cinasa 2 que interactúa con el homeodominio (HIPK2) está asociado con la formación de cálculos renales en una población turca. Método: Se inscribieron en el estudio 129 pacientes con nefrolitiasis cálcica y 67 sujetos control sanos, emparejados por sexo y edad. Las muestras de sangre se recogieron en tubos con EDTA. El ADN de los pacientes se extrajo mediante un sistema de aislamiento de ADN automatizado QIAsymphony®. Se aplicó la prueba χ2 en las comparaciones entre los grupos de pacientes y control con respecto a las diferencias de las frecuencias genotípicas y alélicas. Resultados: No se encontraron diferencias estadísticamente significativas entre los grupos en términos de incidencia de polimorfismo de nucleótido simple (PNS) en alelo simple y alelo doble en las regiones rs2058265 y rs6464214 (p = 0.13 y 0.37, respectivamente). La incidencia de PNS en alelos dobles en pacientes con nefrolitiasis en rs7456421 fue menor que en el grupo control, con una diferencia estadísticamente significativa (p = 0.001). Conclusiones: Las distribuciones de genotipo y alelo de los tres polimorfismos (rs2058265, rs6464214 y rs745642 en HIPK2) no se asociaron con un mayor riesgo de cálculos renales en esta población turca

Türk Turizm Sektörü Konaklama İşletmelerinde Çalışan Yöneticilerin Değerlendirilmesi

Çalışmanın birincil amacı, konaklama işletmelerinde çalışan yöneticilerin vasıflarına uygun bir mesleği icra edip etmediklerini belirlemeye çalışmaktır. Belirtilen hedef doğrultusunda, turizm endüstrisi konaklama işletmesi yöneticilerine anket yöntemi uygulanmış ve sonuçlar analiz edilmiştir. Araştırmanın alt amacı ise çalışanların işe uygun vasıflara sahip elemanlar olup olmadıklarını tespit etmektir. Ayrıca sektörde düşük verim söz konusu ise, bunun arkasında yatan nedenlerin ortaya koyulması tasarlanmıştır

Importance and usage of chromosomal microarray analysis in diagnosing intellectual disability, global developmental delay, and autism; and discovering new loci for these disorders

Abstract Background Chromosomal microarray analysis is a first-stage test that is used for the diagnosis of intellectual disability and global developmental delay. Chromosomal microarray analysis can detect well-known microdeletion syndromes. It also contributes to the identification of genes that are responsible for the phenotypes in the new copy number variations. Results Chromosomal microarray analysis was conducted on 124 patients with intellectual disability and global developmental delay. Multiplex ligation-dependent probe amplification was used for the confirmation of chromosome 22q11.2 deletion/duplication. 26 pathogenic and likely pathogenic copy number variations were detected in 23 patients (18.55%) in a group of 124 Turkish patients with intellectual disability and global developmental delay. Chromosomal microarray analysis revealed pathogenic de novo Copy number variations, such as a novel 2.9-Mb de novo deletion at 18q22 region with intellectual disability and autism spectrum disorder, and a 22q11.2 region homozygote duplication with new clinical features. Conclusion Our data expand the spectrum of 22q11.2 region mutations, reveal new loci responsible from autism spectrum disorder and provide new insights into the genotype–phenotype correlations of intellectual disability and global developmental delay