Okur-Chung neurodevelopmental syndrome (OCNDS; OMIM #617062) is an ultra-rare autosomal dominant disorder caused by heterozygous CSNK2A1 variants encoding CK2α; although the CSNK2A1 Foundation registry lists more than 350 diagnosed individuals worldwide, individual-level phenotypic data have been published for far fewer, and reports from Türkiye remain scarce. We retrospectively studied nine unrelated Turkish probands (4 F/5 M; 11 months to 23 years) from nine medical genetics centers across four geographic regions of Türkiye, diagnosed by exome sequencing (ES; n = 8) or chromosomal microarray (n = 1). A PRISMA 2020-compliant systematic review (inception-April 2026) provided an individual-level comparator pooled with our cohort (n = 61). Six distinct CSNK2A1 alterations were identified: the recurrent p.(Lys198Arg) p + 1 loop hotspot in 4/9 probands (44.4%); novel/rare p.(Arg195Gln) and p.(Asp156His) missense changes; two nonsense variants (p.(Tyr182Ter), p.(Arg333Ter)); and one ~537 kb heterozygous 20p13 contiguous deletion (arr[GRCh37] 20p13(61568_598427)x1). This proband also represents 20p13 deletion syndrome; previously reported cases of that entity were compared with our cohort. Core OCNDS features (developmental delay, intellectual disability, hypotonia, dysmorphism, behavioral disturbance) occurred at frequencies comparable to those in the pooled literature. Adult-onset obesity with type 2 diabetes (2/9) and hypogonadism (2/9), both essentially unreported in the predominantly pediatric pooled literature, were observed in two adolescent/young-adult males (one with p.(Lys198Arg), one with the 20p13 deletion). This series consolidates Lys198 as a recurrent hotspot across ethnically diverse cohorts, extends the structural-variant spectrum with the first Turkish CSNK2A1 contiguous-gene deletion, and supports adult-onset metabolic-reproductive complications as under-recognized OCNDS features. Systematic adolescent and adult metabolic-endocrine surveillance is recommended regardless of variant class.

Introduction:Dual molecular diagnoses are increasingly recognized with expanded genomic testing, and may result in blended phenotypes when two independent pathogenic findings contribute to the clinical presentation. Case Presentation:A 3-year-old female patient presented with seizures beginning at 8 months of age (generalized tonic-clonic), severe global developmental delay/intellectual disability, generalized hypotonia, absent meaningful speech, and microcephaly (head circumference 44.1 cm, <3rd percentile). Craniofacial features included midface retrusion/hypoplasia, thick eyebrows, bilateral epicanthal folds, upslanting palpebral fissures, large ears, a wide mouth, a full lower lip, and a low posterior hairline. Electroencephalography showed age-inappropriate background activity with frequent high-amplitude bifrontal spike-slow wave discharges that often generalized and occasionally displayed a hypsarrhythmia-like pattern. Cranial magnetic resonance imaging was reported as showing a mega cisterna magna variation. Conclusion:Exome sequencing (ES) identified a heterozygous missense variant in HECW2, NM_001348768.2:c.4485G>T p.(Arg1495Ser). Copy-number variant (CNV) analysis of the ES data detected an approximately 2.6 megabase (Mb) heterozygous deletion on chromosome 15, subsequently confirmed by chromosomal microarray analysis as a 2.79 Mb 15q25.2-q25.3 deletion and classified as pathogenic according to American College of Medical Genetics and Genomics/Clinical Genome Resource (ACMG/ClinGen) technical standards. Both alterations were de novo. This case represents a rare dual molecular diagnosis involving a HECW2 missense variant and a 15q25.2-q25.3 deletion, supporting a potential blended phenotype and expanding the molecular and phenotypic spectrum of HECW2-related neurodevelopmental disorder.

Background/Objectives: Advances in the genetic understanding of pheochromocytoma-paraganglioma (PPGL) have considerably refined personalized approaches to diagnosis and management. This study aims to present our institutional experience on the diagnostic characteristics, clinical course, and genetic background of patients with PPGL, in the context of the current literature. Methods: This retrospective analysis included 35 patients diagnosed with PPGL between years 2020 and 2024, all of whom underwent surgical resection and next-generation sequencing for germline mutations in major PPGL susceptibility genes. Clinical presentation, biochemical profile, pathological findings, and follow-up outcomes were compared between mutation-positive and mutation-negative cases. Results: Of the 35 patients with PPGL, germline mutations were identified in 6 patients (17%): 2 in Cluster 1A genes (SDHA, SDHB), 2 in Cluster 1B (VHL), and 2 in Cluster 2 (NF1). Consistent with existing literature, pathogenic germline variants-particularly SDHB and VHL-were identified in our cohort exclusively in patients younger than 30 years (ages 17, 20, and 25). Mutation-positive patients more frequently exhibited noradrenergic or non-secretory profiles (p = 0.01). Among the three non-secretory tumors in the cohort, two harbored genetic mutations (SDHA, NF1). Interestingly, both NF1-positive patients were normotensive-one (c.3496G > A) with a non-secretory tumor and the other (c.2329T > A) presenting at an unusually late age (63 years)-a strikingly atypical spectrum that underscores the phenotypic variability of NF1-associated PPGL. Bilateral disease was observed exclusively in VHL carriers (p = 0.03). Importantly, we identified a rare VHL c.369delG frameshift variant, not previously reported in association with PPGLs, in a patient with PPGL. No significant difference was observed between SDHB loss (p = 0.1) and proliferative indices (mitotic count, Ki-67) (p = 0.07, p = 0.6) between the two groups. During a median follow-up of 24 months (IQR: 18-36), one SDHB-positive patient had a recurrence, while no distant metastases were detected in the remaining mutation carriers. Conclusions: These findings support characteristic clinical patterns among mutation-positive PPGL and underscore the importance of systematic germline testing in all cases-irrespective of age, family history, or biochemical profile-to guide individualized management and enable cascade screening. The identification of a rare VHL c.369delG variant, previously unreported in association with PPGL, within a characteristic VHL-related clinical phenotype highlights the importance of this association. Similarly, atypical NF1 cases emphasize phenotypic variability and reinforce the importance of germline testing even in clinically silent presentations.

The ATP9A gene encodes a P4-type ATPase involved in phospholipid translocation, essential for vesicular trafficking and neuronal development. Pathogenic ATP9A variants cause autosomal recessive neurodevelopmental disorders characterized by intellectual disability and microcephaly, yet the impact of missense variants remains poorly understood. A 7-year-old female patient with cognitive impairment, microcephaly, and developmental delay was admitted to Başakşehir Çam and Sakura City Hospital. Whole exome sequencing (WES) using Illumina technology identified a novel homozygous ATP9A variant, confirmed by Sanger sequencing and segregation analysis. In silico tools (RosettaFold, DynaMut, mCSM, SDM, DUET, AggreScan3D) assessed its structural impact. Quantitative real-time polymerase chain reaction (RT-qPCR) was conducted to evaluate the relative expression levels of ATP9A. WES revealed a homozygous missense variant, ATP9A: NM_006045.3:c.1091G > C:p.(Arg364Thr), classified as variant of uncertain significance based on ACMG guidelines (PP2, PM2, PM3). Protein modeling demonstrated reduced stability (ΔΔG = − 1.51 to − 0.26 kcal/mol), increased flexibility, and a 2.4-fold decrease in solvent accessibility. The variant disrupted polar and hydrophobic interactions within the P-type ATPase IV domain, thereby increasing aggregation propensity. Expression analysis revealed elevated ATP9A mRNA levels, suggesting a compensatory cellular response. This novel ATP9A variant broadens the mutational spectrum of ATP9A-related neurodevelopmental disorders. Structural destabilization of the p.(Arg364Thr) protein may contribute to the patient’s cognitive impairment and microcephaly, warranting further functional studies.

BACKGROUND:Inherited kidney diseases represent a genetically and clinically heterogeneous group of disorders affecting both pediatric and adult populations. Advances in next-generation sequencing (NGS) have improved diagnostic precision; however, genotype-phenotype correlations and diagnostic yield vary substantially across disease entities. METHODS:We retrospectively evaluated 165 patients referred for genetic testing due to suspected inherited kidney disease. Patients were classified into three clinical groups: polycystic kidney disease, Alport syndrome, and other syndromic patients with inherited kidney diseases. Genetic analysis was performed using NGS with Human Phenotype Ontology-based gene filtering and included evaluation of both single-nucleotide variants and copy number variations. RESULTS:Overall diagnostic yield differed markedly between groups. A molecular diagnosis was achieved in 71.4% of Alport patients, 41.0% of PKD patients, and 70.2% of patients in the Other syndromic group. In the Alport group, variants were identified exclusively in COL4A3, COL4A4, and COL4A5, with pathogenicity and gene involvement correlating with disease severity and the presence of extrarenal manifestations. The PKD group showed predominant involvement of PKD1, followed by PKHD1 and PKD2, while a substantial proportion of patients remained genetically negative, reflecting technical and biological complexity. The Other group exhibited pronounced genetic heterogeneity, with variants distributed across multiple genes involved in tubular, glomerular, metabolic, and ciliopathy-related pathways. Computational assessments demonstrated that several variants of uncertain significance (VUS) were located in functionally critical domains and were predicted to disrupt protein stability, intermolecular interactions, or conserved structural motifs, thereby supporting the biological plausibility of their potential pathogenic impact. CONCLUSIONS:Phenotype-driven NGS enables effective molecular diagnosis across diverse inherited kidney diseases while revealing disease-specific differences in diagnostic yield and genotype-phenotype correlations. Systematic inclusion of variants of uncertain significance and careful integration of genetic and clinical data are essential for accurate interpretation and long-term patient management. Collectively, this study enhances understanding of inherited kidney diseases and underscores the value of integrating comprehensive genomic and computational approaches into routine nephrogenetic practice.

Phosphoglucomutase 3 deficiency (PGM3 deficiency) is a rare congenital disorder of glycosylation classically associated with severe immunodeficiency, skeletal abnormalities, and neurodevelopmental impairment. However, emerging evidence suggests that PGM3 deficiency may also present with attenuated or milder clinical phenotypes. In this study, we describe patients with a novel PGM3 variant exhibiting a less severe immunological and clinical presentation, thereby expanding the known phenotypic spectrum of PGM3 deficiency. Demographic-data and Wechsler Intelligence Scale for Children profiles were evaluated alongside laboratory data, including complete blood cell counts, lymphocyte subsets, serum immunoglobulin levels, vaccine antibody titers, and lymphocyte cytokine profiles. Whole exome sequencing was conducted, and phospho-flow assays were utilized for the analysis of p-STATs. Five patients with a mild form of PGM3 deficiency were described, exhibiting a Hyper-IgE Syndrome phenotype without severe skeletal dysplasia or dysmorphism, with the exception of one patient displaying very mild skeletal dysplasia and three patients exhibiting mild to moderate intellectual disability. All patients demonstrated an increase in Natural Killer T cells and a decrease in B cells, alongside an increase in activated CD4 + T cells (CD45RO+), a decrease in naïve CD4 + and CD8 + T cells (CD45RA+ CCR7+), and an increase in TEMRA CD8 + T cells (CD45RA+CCR7–). Functional analysis of all patients revealed impaired PGM3 function, as evidenced by decreased surface expression of gp130 and p-STAT3. Defective glycosylation in PGM3 deficiency leads to reduced gp130 expression and attenuated gp130-dependent STAT3 phosphorylation. The resulting cellular features partially overlap with those observed in STAT3 loss-of-function and gp130 deficiency, supporting a shared signaling mechanism while remaining clinically distinct.

Objective: We aim to documented genetic etiology of epilepsy at a single-center epilepsy outpatient clinic in state hospital. Methods: The patients’ demographic data, clinical and electrophysiologic features, and gene analysis were re-evaluated from medical records of patients with epilepsies between August 2021 and January 2024. The detected variants were searched in gnomAD, ClinVar, DECIPHER, and PubMed databases. The common and distinct features of the phenotype of patients were compared with the literature. Results: The medical records of 354 patients with epilepsy were reviewed. Forty (11.2%) patients were diagnosed with genetic generalized epilepsy. Among them, 37 patients (10.4%) were diagnosed with idiopathic generalized epilepsy, and 3 patients (0.8%) were diagnosed with epilepsy with eyelid myoclonia. We included patients with epilepsy and confirmed genetic etiology at diagnosis. Nine (2.5%) patients with epilepsy and confirmed genetic etiology were included; seven (1.9%) patients had rare monogenic variants in (ZNF142, ZMYND11, DLG4, PEX11B, SCARB2 and GRM-1) genes and two (0.5%) had chromosomal abnormalities (1p36 deletion and 15q15.1 deletion). Conclusion: This study reported genetic etiologies of epilepsy were determined in single-center state hospital. The reported families demonstrate that similar genotypic variations can lead to different phenotypic outcomes. Indeed, similar phenotypic features may result from two distinct genotypic alterations. Specifying the variants and their phenotypic features with diagnostic tools in every single-center are important starting to investigate across the country.

Neurodevelopmental disorders (NDDs) with ataxia are genetically heterogeneous and remain a diagnostic challenge. Recent advances in genomic technologies have facilitated the identification of rare, potentially causative variants in genes not traditionally associated with classic NDD phenotypes. The DNAH14 gene, encoding a dynein axonemal heavy chain involved in ciliary motility, has recently emerged as a novel candidate in neurological syndromes. Here, we report two Turkish siblings presenting with late-onset balance disorder, progressive ataxia, and cognitive impairment. Initial genetic analysis revealed that both siblings also harbor FXN GAA repeat expansions consistent with pathogenic Friedreich's ataxia (FRDA). To elucidate the molecular basis of the patients' cognitive impairment, whole-exome sequencing was performed. This analysis identified a novel homozygous frameshift variant in the DNAH14 gene, located within the conserved linker domain upstream of the motor core, which is critical for ATP hydrolysis and microtubule interactions. The variant is absent from population databases, predicted to be deleterious by multiple in silico algorithms, and segregates in the family in a manner consistent with autosomal recessive inheritance. The coexistence of FRDA expansions and a truncating DNAH14 variant suggests a potential dual genetic contribution to the observed phenotype, in which FRDA-associated pathology likely underlies the ataxia, while DNAH14 disruption may contribute to additional neurodevelopmental features. This is the first report describing the co-occurrence of FRDA and a homozygous truncating DNAH14 variant in the same individuals, broadening our understanding of overlapping neurogenetic mechanisms. Our findings expand the phenotypic spectrum of DNAH14-related disorders and highlight the importance of considering multilocus pathogenic variants in patients with complex or atypical ataxia presentations.

Introduction:RASopathies are among the most prevalent genetic syndromes caused by variants in the Ras/MAPK signaling pathway, affecting various systems such as the heart, craniofacial features, skin, musculoskeletal system, hearing, and vision. They can also increase the risk of secondary malignancies. Despite clinical overlaps, distinguishing features are crucial for diagnosis, as different variants lead to distinct clinical implications. This study reviews the molecular and clinical characteristics of RASopathies, focusing on neurofibromatosis type 1 (NF1) and non-NF1 RASopathies. Methods:The study analyzed 76 patients referred to our outpatient clinic over a 6-year period, all of whom were clinically diagnosed with RASopathy and confirmed in most cases by molecular testing. Patient files, clinical photographs, and laboratory results were reviewed and analyzed. A targeted multigene next-generation sequencing panel test was performed, followed by Sanger sequencing for both confirmation and segregation analysis. Multiplex ligation-dependent probe amplification was conducted in a patient with normal sequence results but strong clinical suspicion, to identify potential deletions. Results:We identified 44 pathogenic, 25 likely pathogenic variants, and 6 variants of uncertain significance based on American College of Medical Genetics and Genomics (ACMG) criteria. Among these, 14 novel variants were found - 13 in the NF1 gene and one in SOS1. NF1 variants were present in 51 cases. Additional variants, likely to represent clinically significant findings, were identified in PTPN11 (n = 11), RAF1 (n = 4), SOS1 (n = 3), RIT1 (n = 3), KRAS (n = 1), NRAS (n = 1), SOS2 (n = 1), and BRAF (n = 1). Diagnoses included 49 patients with NF1, 21 with Noonan syndrome, 2 with neurofibromatosis-Noonan syndrome, 2 with Noonan syndrome with multiple lentigines, and 1 with cardiofaciocutaneous syndrome. Here, 12% of NF1 variants were located in exon 21, 36% of PTPN11 variants in exon 3, and 75% of RAF1 variants in exon 7. Conclusion:RASopathies have a broad molecular and clinical spectrum, complicating diagnosis and management. Accurate clinical correlation and molecular analysis are essential, as different RASopathy syndromes can result from variants in the same genes, while the same syndrome may arise from different genetic alterations. This study identifies novel variants and emphasizes the need for precise diagnostic approaches in these complex disorders.

Introduction:Meckel-Gruber syndrome (MKS) is a clinically and genetically heterogeneous ciliopathy characterized by a triad of occipital encephalocele, polycystic kidneys, and postaxial polydactyly. Almost all of them are lethal in the prenatal or first postnatal periods. It is usually diagnosed clinically with a detailed prenatal ultrasound examination. Variants have been reported in at least 14 different genes. Case Presentation:We report a male fetus with oligohydramnios, large kidneys with microcysts covering the entire abdomen, postaxial polydactyly of the hands, bilateral pes equinovarus, encephalocele, microphthalmia, short extremities, and a mass lesion under the diaphragm. Termination was recommended to the family due to severe findings. Fetal skin biopsy and parental peripheral blood samples were obtained to investigate the potential pathogenic variants associated with MKS via clinical exome sequencing and Sanger sequencing. Conclusion:The fetus was homozygous for the c.16del (p.Leu6SerfsTer15) variant in the TCTN1 (NM_001082538.3), and both parents were heterozygous for the variant. Genetic diagnosis is very important in terms of counseling for subsequent pregnancies. To our knowledge, this is the third Meckel-Gruber case in the literature caused by the TCTN1, and a novel likely pathogenic variant was detected.

Inherited retinal diseases (IRDs) constitute a heterogeneous group of clinically and genetically diverse conditions, standing as a primary cause of visual impairment among individuals aged 15-45, with an estimated incidence of 1:2000. Our study aimed to comprehensively evaluate the genetic variants underlying IRDs in the Turkish population. This study included 50 unrelated Turkish IRD patients and their families. Genomic DNA was extracted from each participant, and candidate variants were identified via next-generation sequencing to determine their pathogenicity. We detected variants in 58% of the patients, of which six novel variants were identified. Among these, 16 cases exhibited variants associated with retinitis pigmentosa and Stargardt disease, while 13 presented variants linked to other retinal diseases. The spectrum of identified variants included 21 homozygous cases and five compound heterozygous variants, both indicative of autosomal recessive inheritance. Three cases revealed heterozygous variants suggestive of autosomal dominant inheritance, and two cases featured hemizygous variants suggestive of X-linked inheritance. Importantly, no matches with copy number variants were detected in our analysis. This study comprehensively portrays clinical and genetic profiles within the Turkish population affected by IRDs. Identifying novel variants and delineating inheritance patterns contribute to a deeper understanding of the genetic diagnosis of IRDs, paving the way for more precise diagnostic and therapeutic interventions.

Background: This retrospective study aims to present the clinical and genetic data of patients diagnosed with immunodeficiency through genetic diagnostic methods. It is essential to investigate the impact of genetic risk factors, such as consanguinity, on immunodeficiency, identify the underlying genetic variants, and assess potential risks. Identifying genetic defects in patients with unknown etiology is critical for accurate diagnosis and effective treatment. Methodology: Patient histories were evaluated, and detailed clinical findings were recorded. Genetic analyses were performed, identifying eight different variants consistent with autosomal recessive inheritance. The American College of Medical Genetics and Genomics classification criteria were utilized to assess several pathogenic and likely pathogenic variants associated with various immunodeficiency disorders. Results: Several pathogenic and likely pathogenic variants were identified, related to immunodeficiency disorders such as severe combined ımmunodeficiency due to ADA deficiency and LIG4 syndrome. A significant proportion of patients had a history of consanguinity. The clinical variability observed emphasizes the importance of comprehensive genetic evaluation. Whole exome sequencing (WES) proved effective in uncovering the genetic causes of unexplained immunodeficiency symptoms. Conclusion: This study highlights the critical role of genetic testing in diagnosing immunodeficiency disorders. WES and next-generation sequencing technologies were particularly useful in identifying the genetic basis of immunodeficiency in patients with unexplained symptoms. Genetic evaluation enables personalized treatment strategies, improving patient management and outcomes. Comprehensive genetic assessments are especially important in populations with high consanguinity rates.

The post-transcriptional modification of tRNAs plays a crucial role in tRNA structure and function. Pathogenic variants in tRNA-modification enzymes have been implicated in a wide range of human neurodevelopmental and neurological disorders. However, the molecular basis for many of these disorders remains unknown. Here, we describe a comprehensive cohort of 43 individuals from 31 unrelated families with bi-allelic variants in tRNA methyltransferase 1 (TRMT1). These individuals present with a neurodevelopmental disorder universally characterized by developmental delay and intellectual disability, accompanied by variable behavioral abnormalities, epilepsy, and facial dysmorphism. The identified variants include ultra-rare TRMT1 variants, comprising missense and predicted loss-of-function variants, which segregate with the observed clinical pathology. Our findings reveal that several variants lead to mis-splicing and a consequent loss of TRMT1 protein accumulation. Moreover, cells derived from individuals harboring TRMT1 variants exhibit a deficiency in tRNA modifications catalyzed by TRMT1. Molecular analysis reveals distinct regions of TRMT1 required for tRNA-modification activity and binding. Notably, depletion of Trmt1 protein in zebrafish is sufficient to induce developmental and behavioral phenotypes along with gene-expression changes associated with disrupted cell cycle, immune response, and neurodegenerative disorders. Altogether, these findings demonstrate that loss of TRMT1-catalyzed tRNA modifications leads to intellectual disability and provides insight into the molecular underpinnings of tRNA-modification deficiency caused by pathogenic TRMT1 variants.

Hypotrichosis with juvenile macular dystrophy (HMJD) is a rare autosomal recessive disease that leads to blindness in the first thirty years of life. It is characterized by hypotrichosis and progressive macular degeneration. Approximately fifty cases of this very rare entity have been reported. HMJD is associated with mutations in the CDH3 gene. This article presents the case of a 4-year-old child who visited the dermatology clinic with hypotrichosis and underwent genetic screening due to clinical suspicion. His father, who was initially diagnosed with retinitis pigmentosa, was later identified as having HMJD. In both cases, the homozygous c.830del variant in the CDH3 gene was detected. Considering eye involvement, revealed bilateral pigmentary changes at the fovea and loss of the outer retinal layers. In the second case, marked pigmentary changes in the posterior pole bilateral photoreceptor layer irregularity and retinal pigment epithelium atrophy, and a full-thickness macular hole on the right eye and foveal atrophy on the left eye were found. This is the first report of homozygous Turkish father-daughter cases with HJMD. Our discoveries offer deeper insights into CDH3-associated HJMD, providing valuable knowledge that could enhance the expertise of both dermatologists and ophthalmologists.

Aim: This study aimed to evaluate coagulation disorders in patients with argininemia associated with arginase 1 gene mutations and the control of these disorders with sodium benzoate treatment. Materials and Methods: Five argininemia patients followed up in the Pediatric Metabolism Clinic in University of Health Sciences T & uuml;rkiye, Ba & scedil;ak & scedil;ehir & Ccedil;am and Sakura City Hospital, were included in this study. The patients initially received protein-restricted diet treatment, while their ammonia, platelet count, liver enzymes and coagulation parameters were measured regularly. Later, sodium benzoate was added to the treatment and the same parameters were measured at 1-month intervals. Results: In the coagulation parameters measured after sodium benzoate treatment, one out ofthe five patients showed complete improvement, three had partial improvement, and one had no change. In the patients with coagulation disorders, factor VII and IX levels were low, while arginine levels remained above 250 mu mol/L. Conclusion: The pathophysiology of coagulation disorders in patients with argininemia has not yet been fully elucidated, but it is thought that high arginine levels may affect the synthesis of short-lived coagulation factors. Adding sodium benzoate to dietary therapy may contribute to both the control of arginine levels and an improvement in coagulation parameters. This study demonstrates the importance of coagulation monitoring in those patients with argininemia and the potential therapeutic role of sodium benzoate.

Hyaline fibromatosis syndrome (HFS) is an autosomal recessive disorder caused by variants in the ANTXR2 gene. Clinically, HFS is characterized by papular and nodular skin lesions, gingival hyperplasia, joint contractures, and bone involvement in variable degrees. In this report, we present a 3-year-old Syrian boy with HFS, detailing his clinical and genetic profile, furthering the understanding of genotype-phenotype correlation in the ANTXR2 gene and HFS.

OBJECTIVES:The catalytic subunit of NatA, the main component of the N-terminal acetyltransferase complex, which is involved in most of the acetylation of the human proteome, is encoded by the NAA10 gene. Mutations in the NAA10 gene lead to neurodegenerative diseases associated with disruption of acetylation. Ogden syndrome (OS) is a rare X-linked recessive or dominantly inherited disorder associated with NAA10 gene mutations, characterized by variable findings such as autism spectrum disorder, intellectual disability, and cardiac anomalies. In this article, it is aimed to clarify the functionality of two novel NAA10 gene variants in two female patients with OS. METHODS:A whole-exome sequencing (WES) study was performed from the blood samples of the patients. The effects of the two variants found by tertiary structure modeling, protein stability analysis, and molecular docking analyses on NAA10 were examined. RESULTS:Autism, intellectual retardation, and epilepsy were prominent in the patients, and heterozygous variants c.346C>T and c.439A>T in the NAA10 gene were detected in WES. The clinical findings were compatible with OS. The p.Arg116Trp and p.Met147Leu changes in the NAA10 gene caused changes in the overall topological structure of NAA10, including the substrate and ligand binding site. CONCLUSION:In this study, c.346C>T and c.439A>T variants were found to alter the functional stability, structure, and energy of NAA10. Functional analyses of NAA10 variants in two rare OS patients have once again demonstrated that novel variants are essential studies for phenotype-genotype correlation association steps.

Hypohidrotic ectodermal dysplasias are a genetic condition affecting ectoderm-derived structures such as hair, teeth, nails, and sweat glands, resulting from variations in the EDA, EDAR, EDARADD, and WNT10A genes. This study examined 32 cases from 25 unrelated families from Türkiye, identifying seven novel variants in the EDA, EDAR, and WNT10A genes. The distribution of genetic alterations across the cohort revealed that 44% of the families (11/25) harbored variants in EDA, whereas EDAR and WNT10A variants were identified in 32% (8/25) and 24% (6/25) of families, respectively. Clinical evaluation revealed the characteristic hypohidrotic ectodermal dysplasia triad of hypotrichosis, hypodontia, and hypohidrosis was observed in 87.5% of cases, along with other symptoms such as dry skin, atopic dermatitis, and developmental delays. All cases presented with hair, eyebrow, and eyelash abnormalities, ranging in severity from subtle thinning to marked hypotrichosis. Among the cohort, one case exhibited severe atopic dermatitis as the predominant symptom. Targeted next-generation sequencing and clinical exome sequencing were employed to determine the genetic basis of the condition, emphasizing the importance of early diagnosis for targeted interventions. This study expands the genetic and phenotypic spectrum of hypohidrotic ectodermal dysplasia, presenting a comprehensive overview of molecular findings and genotype-phenotype correlations in the population from the Turkish population.