A Korean Family Presenting with Renal Cysts and Maturity-Onset Diabetes of the Young Caused by a Novel In-Frame Deletion of HNF1B.

Maturity-onset diabetes of the young (MODY; OMIM # 606391) comprises a cluster of inherited disorders within non-autoimmune diabetes mellitus (DM), typically emerging during adolescence or young adulthood. We report a novel in-frame deletion of HNF1B in a family with renal cysts and MODY, furthering our understanding of HNF1B-related phenotypes. We conducted sequential genetic testing to investigate the glucose intolerance, renal cysts, hepatic cysts, and agenesis of the dorsal pancreas observed in the proband. A comprehensive clinical exome sequencing approach using a Celemics G-Mendeliome Clinical Exome Sequencing Panel was employed. Considering the clinical manifestations observed in the proband, gene panel sequencing identified a heterozygous HNF1B variant, c.36_38delCCT/p.(Leu13del) (reference transcript ID: NM_000458.4), as the most likely cause of MODY in the proband. The patient's clinical presentation was consistent with MODY caused by the HNF1B variant, showing signs of glucose intolerance, renal cysts, hepatic cysts, and agenesis of the dorsal pancreas. Sanger sequencing confirmed the same HNF1B variant and established the paternally inherited autosomal dominant status of the heterozygous variant in the patient, as well as in his father and sister. The presence of early-onset diabetes, renal cysts, a family history of the condition, and nephropathy appearing before or after the diagnosis of diabetes mellitus (DM) suggests a diagnosis of HNF1B-MODY5. Early diagnosis is crucial for preventing complications of DM, enabling family screening, providing pre-conceptional genetic counseling, and monitoring kidney function decline.

Molecular analysis of 31 cases with fetal skeletal dysplasia.

OBJECTIVES: The aim of this study was to describe the prenatal ultrasound findings of fetuses with skeletal dysplasia and to evaluate the genetic variations by molecular genetic analysis. METHODS: Between August 1, 2018 and March 1, 2023, we conducted a retrospective case series at a tertiary referral center involving patients with fetal skeletal abnormalities. For cases referred for a possible diagnosis of fetal skeletal dysplasia, an ultrasound database and prenatal genetic counseling records were first searched. Terminated cases diagnosed with skeletal dysplasia by pathologic and radiologic findings and cases with skeletal dysplasia proven by postnatal clinical findings were included in the study. RESULTS: Between 2018 and 2023, a total of 64 cases were diagnosed as skeletal dysplasia based on radiologic findings, pathologic findings, and clinical features. The median week of the first ultrasound performed on patients is 19 0/7 weeks, while the median week of the ultrasound in which skeletal dysplasia is suspected is 21 3/7 weeks. Although micromelia was evaluated as a common feature in all cases, the most common concomitant anomaly was thoracic hypoplasia. Exome sequencing analysis was achieved in 31 (48 %) of cases. In 31 cases, in total of 35 pathogenic single gene mutations and 5 VUS (variants of uncertain significance) variants composing of 23 autosomal dominant, 10 autosomal recessive and 2 X linked recessive mutations were determined. CONCLUSIONS: Prenatal ultrasound findings can lead us to specific diagnoses, and with the appropriate molecular analysis method, a definitive diagnosis can be made without wasting time and money.

Nemaline Myopathy With a Compound Heterozygous Mutation: A Case Report.

A class of genetically based congenital myopathies known as nemaline myopathies is defined by the development of nemaline rods within muscle fibers. We present a case involving an eight-year-old boy who presented with a history of delayed motor development, proximal muscle weakness, and neck flexor weakness. Muscle enzymes were normal, and electrophysiological studies revealed a myopathic pattern. Nemaline myopathy (NM) was diagnosed with the help of clinical exome sequencing, which showed a compound heterozygous mutation with a novel variant in the nebulin (NEB) gene.

A Copernican revolution of multigenic analysis: A retrospective study on clinical exome sequencing in unclear genetic disorders.

Despite the inevitable shift in medical practice towards a deeper understanding of disease etiology and progression through multigenic analysis, the profound historical impact of Mendelian diseases cannot be overlooked. These diseases, such as cystic fibrosis and thalassemia, are characterized by a single variant in a single gene leading to clinical conditions, and have significantly shaped our medical knowledge and treatments. In this respect, the monogenic approach inevitably results in the underutilization of Next-Generation Sequencing (NGS) data. Herein, a retrospective study was performed to assess the diagnostic value of the clinical exome in 32 probands with specific phenotypic characteristics (patients with autoinflammation and immunological dysregulation, N = 20; patients diagnosed with Hemolytic uremic syndrome N = 9; and patients with Waldenström macroglobulinemia, N = 3). A gene enrichment analysis was performed using the *. VCF file generated by SOPHiA-DDM-v4. This analysis selected a subset of genes containing pathogenic or likely pathogenic variants with autosomal dominant (AD) inheritance. In addition, all variants of uncertain significance (VUS) were included, filtered by AD inheritance mode, the presence of compound heterozygotes, and a minor allele frequency (MAF) cutoff of 0.05 %. The aim of the pipeline described here is based on a perspective shift that focuses on analyzing patients' gene assets, offering new light on the complex interplay between genetics and disease presentation. Integrating this approach into clinical practices could significantly enhance the management of patients with rare genetic disorders.

Investigation of patients with childhood epilepsy in single center: Comprehensive genetic testing experience.

INTRODUCTION: Epilepsy is a common multifactorial neurological disease usually diagnosed during childhood. In this study, we present the contribution of consecutive genetic testing to the genetic diagnostic yield of childhood epilepsy. METHODS: In 100 children (53 female, 47 male) with epilepsy, targeted sequencing (TS) and clinical exome sequencing (CES) were performed. All cases (n = 100) included in the study were epilepsy patients. In addition, we investigated the genetic diagnosis rates according to the associated co-occurring findings (including developmental delay/intellectual disability, brain malformations, macro-/microcephaly, and dysmorphic features). RESULTS: The overall diagnostic rate in this study was 33% (n = 33 patients). We identified 11 novel variants in WDR45, ARX, PCDH19, SCN1A, CACNA1A, LGI1, ASPM, MECP2, NF1, TSC2, and CDK13. Genetic diagnosis rates were as follows: cases with developmental delay/intellectual disability 38.7% (24/62) and without developmental delay/intellectual disability 23.6% (9/38); cases with brain malformations 46.8% (15/32) and without brain malformations 25% (16/64); cases with macro-/microcephaly 50% (6/12) and without macro-/microcephaly 28.4% (25/88); and cases with dysmorphic features 48.2% (14/29) and without dysmorphic features 23.9% (17/71). CONCLUSION: Genotype-phenotype correlation is even more important in diseases such as epilepsy, which include many genes and variants of these genes in etiopathogenesis. We presented the clinical findings of the cases carrying 11 novel variants in detail, including dysmorphic features, accompanying neurodevelopmental disorders, EEG results, and brain MRI results.

Characterization of a New Variant in ARHGAP31 Probably Involved in Adams-Oliver Syndrome in a Family with a Variable Phenotypic Spectrum.

Adams-Oliver syndrome is a rare inherited condition characterized by scalp defects and limb abnormalities. It is caused by variants in different genes such as ARHGAP31. Here, we used an interdisciplinary approach to study a family with lower limb anomalies. We identified a novel variant in the ARHGAP31 gene that is predicted to result in a truncated protein with a constitutively activated catalytic site due to the loss of 688 amino acids involved in the C-terminal domain, essential for protein auto-inhibition. Pathogenic variants in ARHGAP31 exon 12, leading to a premature protein termination, are associated with Adams-Oliver syndrome. Bioinformatic analysis was useful to elucidate the impact of the identified genetic variant on protein structure. To better understand the impact of the identified variant, 3D protein models were predicted for the ARHGAP31 wild type, the newly discovered variant, and other pathogenetic alterations already reported. Our study identified a novel variant probably involved in Adams-Oliver syndrome and increased the evidence on the phenotypic variability in patients affected by this syndrome, underlining the importance of translational research, including experimental and bioinformatics analyses. This strategy represents a successful model to investigate molecular mechanisms involved in syndrome occurrence.

The Phenotypic Spectrum of Desanto-Shinawi Syndrome: A Comparative Report of the First Reported Case in Turkey.

DeSanto-Shinawi syndrome (DESSH, OMIM #616708) is a rare genetic disorder caused by pathogenic variants in the WAC gene. This syndrome is characterized by a wide range of physical and neurological symptoms including dysmorphic features, developmental delay, intellectual disability, and behavioral abnormalities. DESSH was described by DeSanto in 2015, and since then, only a few dozen cases have been reported worldwide. Recent research has focused on identifying the underlying genetic cause of the syndrome as well as exploring potential treatments. In this report, we describe a female case who had dysmorphic features including long palpebral fissures, depressed nasal root, mild bulbous nasal tip, thin upper lip, hypertrichosis, short fingers, and intellectual disability, speech delay, and motor retardation. In addition, she had behavioral abnormalities such as agitation, anxiety, and attention deficit hyperactivity disorder (ADHD). Clinical exome sequencing showed a pathogenic heterozygous nonsense variant in exon 13 of the WAC gene c.1837C>T, p.(Arg613Ter) with de novo inheritance. To the best of our knowledge, this is the first case of DESSH reported from Turkey. We aimed to report this rare syndrome and compare the clinical findings of our case with previously reported cases in the literature.

Prenatal Diagnosis by Trio Clinical Exome Sequencing: Single Center Experience.

Fetal anomalies, characterized by structural or functional abnormalities occurring during intrauterine life, pose a significant medical challenge, with a notable prevalence, affecting approximately 2-3% of live births and 20% of spontaneous miscarriages. This study aims to identify the genetic cause of ultrasound anomalies through clinical exome sequencing (CES) analysis. The focus is on utilizing CES analysis in a trio setting, involving the fetuses and both parents. To achieve this objective, prenatal trio clinical exome sequencing was conducted in 51 fetuseses exhibiting ultrasound anomalies with previously negative results from chromosomal microarray (CMA) analysis. The study revealed pathogenic variants in 24% of the analyzed cases (12 out of 51). It is worth noting that the findings include de novo variants in 50% of cases and the transmission of causative variants from asymptomatic parents in 50% of cases. Trio clinical exome sequencing stands out as a crucial tool in advancing prenatal diagnostics, surpassing the effectiveness of relying solely on chromosomal microarray analysis. This underscores its potential to become a routine diagnostic standard in prenatal care, particularly for cases involving ultrasound anomalies.

The First Korean Case with Cardiac, Facial, and Digital Anomalies with Developmental Delay Caused by De Novo TRAF7 p.Arg655Gln Variant.

TRAF7-related disorders represent some of the rarest inherited disorders, exhibiting clinical features that overlap with cardiac, facial, and digital anomalies with developmental delay (CAFDADD) syndrome, as well as blepharophimosis-mental retardation syndrome (BMRS). A 36-year-old male, presenting with total blindness, blepharophimosis, and intellectual disability, was admitted for the assessment of resting dyspnea several months previously. He had a history of being diagnosed with obstructive sleep apnea (OSA). Transesophageal and transthoracic echocardiography unveiled right ventricular dilatation without significant pulmonary hypertension, bicuspid aortic valve with aortic root aneurysm, and aortic regurgitation in the proband. Sanger sequencing identified a de novo TRAF7 variant (c.1964G>A; p.Arg655Gln). Subsequently, aortic root replacement using the Bentall procedure was performed. However, despite the surgery, he continued to experience dyspnea. Upon re-evaluating OSA with polysomnography, it was discovered that continuous positive airway pressure support alleviated his symptoms. The underlying cause of his symptoms was attributed to OSA, likely exacerbated by the vertebral anomaly and short neck associated with CAFDADD syndrome. Clinicians should be attentive to the symptoms associated with OSA as it is a potentially serious medical condition in patients with TRAF7 variants.

De novo missense variants in exon 9 of SEPHS1 cause a neurodevelopmental condition with developmental delay, poor growth, hypotonia, and dysmorphic features.

Selenophosphate synthetase (SEPHS) plays an essential role in selenium metabolism. Two mammalian SEPHS paralogues, SEPHS1 and SEPHS2, share high sequence identity and structural homology with SEPHS. Here, we report nine individuals from eight families with developmental delay, growth and feeding problems, hypotonia, and dysmorphic features, all with heterozygous missense variants in SEPHS1. Eight of these individuals had a recurrent variant at amino acid position 371 of SEPHS1 (p.Arg371Trp, p.Arg371Gln, and p.Arg371Gly); seven of these variants were known to be de novo. Structural modeling and biochemical assays were used to understand the effect of these variants on SEPHS1 function. We found that a variant at residue Trp352 results in local structural changes of the C-terminal region of SEPHS1 that decrease the overall thermal stability of the enzyme. In contrast, variants of a solvent-exposed residue Arg371 do not impact enzyme stability and folding but could modulate direct protein-protein interactions of SEPSH1 with cellular factors in promoting cell proliferation and development. In neuronal SH-SY5Y cells, we assessed the impact of SEPHS1 variants on cell proliferation and ROS production and investigated the mRNA expression levels of genes encoding stress-related selenoproteins. Our findings provided evidence that the identified SEPHS1 variants enhance cell proliferation by modulating ROS homeostasis. Our study supports the hypothesis that SEPHS1 plays a critical role during human development and provides a basis for further investigation into the molecular mechanisms employed by SEPHS1. Furthermore, our data suggest that variants in SEPHS1 are associated with a neurodevelopmental disorder.

A novel missense variant in OTUD5 causes X-linked multiple congenital anomalies-neurodevelopmental syndrome.

BACKGROUND: The OTUD5 gene encodes a deubiquitinating enzyme (DUB) of the OTU family. Variants of OTUD5 are associated with X-linked multiple congenital anomalies-neurodevelopmental syndrome (MCAND). The case described in this study expands the clinical and molecular spectrum of OTUD5. METHODS: Trio-based clinical exome sequencing (trio-CES) was performed on a Chinese boy with a clinical phenotype and both of his parents. Sanger sequencing was employed for validation of the variant detected. RESULTS: The patient presented with characteristic facial features, intellectual disability, motor/language/cognitive, and global developmental delays, limb contractures, and kidney abnormalities, and trio-CES identified a de novo missense variant, c.1305T>A, of the OTUD5 gene. DISCUSSION: We describe OTUD5 gene variation in the Chinese population, with the first report of this variant. Additionally, we provide a comprehensive summary of all published cases of MCAND to date, in order to elucidate the primary clinical features of the syndrome and the variability in phenotype severity. This case expands the genetic and clinical phenotypic spectrum of OTUD5-associated MCAND.

Comprehensive assessment of the genetic characteristics of small for gestational age newborns in NICU: from diagnosis of genetic disorders to prediction of prognosis.

BACKGROUND: In China, ~1,072,100 small for gestational age (SGA) births occur annually. These SGA newborns are a high-risk population of developmental delay. Our study aimed to evaluate the genetic profile of SGA newborns in the newborn intensive care unit (NICU) and establish a prognosis prediction model by combining clinical and genetic factors. METHODS: A cohort of 723 SGA and 1317 appropriate for gestational age (AGA) newborns were recruited between June 2018 and June 2020. Clinical exome sequencing was performed for each newborn. The gene-based rare-variant collapsing analyses and the gene burden test were applied to identify the risk genes for SGA and SGA with poor prognosis. The Gradient Boosting Machine framework was used to generate two models to predict the prognosis of SGA. The performance of two models were validated with an independent cohort of 115 SGA newborns without genetic diagnosis from July 2020 to April 2022. All newborns in this study were recruited through the China Neonatal Genomes Project (CNGP) and were hospitalized in NICU, Children's Hospital of Fudan University, Shanghai, China. RESULTS: Among the 723 SGA newborns, 88(12.2%) received genetic diagnosis, including 42(47.7%) with monogenic diseases and 46(52.3%) with chromosomal abnormalities. SGA with genetic diagnosis showed higher rates in severe SGA(54.5% vs. 41.9%, P=0.0025) than SGA without genetic diagnosis. SGA with chromosomal abnormalities showed higher incidences of physical and neurodevelopmental delay compared to those with monogenic diseases (45.7% vs. 19.0%, P=0.012). We filtered out 3 genes (ITGB4, TXNRD2, RRM2B) as potential causative genes for SGA and 1 gene (ADIPOQ) as potential causative gene for SGA with poor prognosis. The model integrating clinical and genetic factors demonstrated a higher area under the receiver operating characteristic curve (AUC) over the model based solely on clinical factors in both the SGA-model generation dataset (AUC=0.9[95% confidence interval 0.84-0.96] vs. AUC=0.74 [0.64-0.84]; P=0.00196) and the independent SGA-validation dataset (AUC=0.76 [0.6-0.93] vs. AUC=0.53[0.29-0.76]; P=0.0117). CONCLUSION: SGA newborns in NICU presented with roughly equal proportions of monogenic and chromosomal abnormalities. Chromosomal disorders were associated with poorer prognosis. The rare-variant collapsing analyses studies have the ability to identify potential causative factors associated with growth and development. The SGA prognosis prediction model integrating genetic and clinical factors outperformed that relying solely on clinical factors. The application of genetic sequencing in hospitalized SGA newborns may improve early genetic diagnosis and prognosis prediction.

CHD2 pathogenic nonsense variant in a three-generation family with variable phenotype and a paracentric inversion 16: Case report.

Chromosomal inversions are usually balanced structural chromosomal rearrangements that do not have an impact on the clinical phenotype of a carrier. The main clinical consequence of inversions is the risk for unbalanced gametes and offspring with severe phenotypes. Rarely though, inversions are associated with a phenotype, mainly due to submicroscopic Copy Number Variants (CNVs) or disruption at the breakpoints of a functionally important gene and/or genomic elements. In this study, a paracentric inversion of chromosome 16 [inv(16)(q22.3q24.1)] was identified in a three-generation family with discordant phenotypes with/without epilepsy and/or intellectual impairment, as well as with an unaffected carrier. This finding was confirmed by fluorescence in situ hybridization (FISH). Genetic investigation, initially with chromosomal microarray (CMA), did not reveal any copy number variants. Finally, Clinical Exome Sequencing (CES), detected the presence of a pathogenic nonsense variant (rs797044912) in the Chromodomain Helicase DNA-binding protein 2 (CHD2) gene [NM_001271.4:c.5035C>T p.(Arg1679Ter)]. CHD2 pathogenic variants have been associated with Developmental and Epileptic Encephalopathy-94 (DEE-94), a rare yet severe condition, characterized by developmental delay, seizures with an early onset, intellectual impairment, autism spectrum disorder, and sometimes behavioral issues. Family testing showed that the variant segregated with phenotypic heterogeneity in the affected individuals and appears to be causative. To the best of our knowledge, this is the first CHD2 pathogenic variant segregating in a three-generation family and the fourth familial case reported. These results further support our previous findings that familial, balanced rearrangements with discordant phenotypes in the same family are, in the vast majority, coincidental.

Relevance of next generation sequencing (NGS) data re-analysis in the diagnosis of monogenic diseases leading to organ failure.

BACKGROUND: In 2018, our center started a program to offer genetic diagnosis to patients with kidney and liver monogenic rare conditions, potentially eligible for organ transplantation. We exploited a clinical exome sequencing approach, followed by analyses of in silico gene panels tailored to clinical suspicions, obtaining detection rates in line with what reported in literature. However, a percentage of patients remains without a definitive genetic diagnosis. This work aims to evaluate the utility of NGS data re-analysis for those patients with an inconclusive or negative genetic test at the time of first analysis considering that (i) the advance of alignment and variant calling processes progressively improve the detection rate, limiting false positives and false negatives; (ii) gene panels are periodically updated and (iii) variant annotation may change over time. METHODS: 114 patients, recruited between 2018 and 2020, with an inconclusive or negative NGS report at the time of first analysis, were included in the study. Re-alignment and variant calling of previously generated sequencing raw data were performed using the GenomSys Variant Analyzer software. RESULTS: 21 previously not reported potentially causative variants were identified in 20 patients. In most cases (n = 19), causal variants were retrieved out of the re-classification from likely benign to variants of unknown significance (VUS). In one case, the variant was included because of inclusion in the analysis of a newly disease-associated gene, not present in the original gene panel, and in another one due to the improved data alignment process. Whenever possible, variants were validated with Sanger sequencing and family segregation studies. As of now, 16 out of 20 patients have been analyzed and variants confirmed in 8 patients. Specifically, in two pediatric patients, causative variants were de novo mutations while in the others, the variant was present also in other affected relatives. In the remaining patients, variants were present also in non-affected parents, raising questions on their re-classification. CONCLUSIONS: Overall, these data indicate that periodic and systematic re-analysis of negative or inconclusive NGS data reports can lead to new variant identification or reclassification in a small but significant proportion of cases, with benefits for patients' management.

Clinical Utility of Proband Only Clinical Exome Sequencing in Neurodevelopmental Disorders.

Chromosomal microarray is recommended as the first line of investigation in neurodevelopmental disorders (NDDs). However, advances in next-generation sequencing have unraveled more than 900 genes associated with NDDs, thus improving the genetic diagnosis. Therefore, this study was conducted to explore the utility of clinical exome sequencing (CES) in NDDs from a tertiary care centre in India. A retrospective observational analysis of 78 children with NDDs for whom CES was performed between 2017 and 2021 was conducted. The American College of Medical Genetics and Genomics (ACMG) criteria were used to classify the variants. The mean age was 5.8 ± 3.6 y, and 42 (53%) were male. Pathogenic, likely pathogenic, and variants of uncertain significance (VUS) were observed in 22 (28.2%), 10 (12.8%), and 26 (33.3%) patients, respectively, which included five copy number variants. The diagnostic yield for pathogenic and likely pathogenic variants in NDDs by CES was 41%, which was reasonably high.

Validation of clinical exome sequencing in the diagnostic procedure of patients with intellectual disability in clinical practice.

Intellectual disability (ID) has a prevalence of 1-3% and aproximately 30-50% of ID cases have a genetic cause. Development of next-generation sequencing has shown a high diagnostic potential. The aim of this work was to evaluate the diagnostic yield of clinical exome sequencing in 188 ID patients and the economic impact of its introduction in clinical practice. An analysis of diagnostic yield according to the different clinical variables was performed in order to establish an efficient diagnostic protocol for ID patients. Diagnostic yield of clinical exome sequencing was significant (34%) supporting its utility in diagnosis of ID patients. Wide genetic heterogeneity and predominance of autosomal dominant de novo variants in ID patients were observed. Time to diagnosis was shortened and diagnostic study costs decreased by 62% after implementation of clinical exome sequencing. No association was found between any of the variables analyzed and a higher diagnostic yield; added to the fact that many of the diagnoses weren't clinically detectable, the reduction of time to diagnosis and the economic savings with respect to classical diagnostic studies, strengthen the clinical and economical convenience of early implementation of clinical exome sequencing in the diagnostic workup of ID patients in clinical practice.

Corrigendum: Genetic diagnosis of inborn errors of immunity using clinical exome sequencing.

[This corrects the article DOI: 10.3389/fimmu.2023.1178582.].

Genetic diagnosis of inborn errors of immunity using clinical exome sequencing.

Inborn errors of immunity (IEI) include a variety of heterogeneous genetic disorders in which defects in the immune system lead to an increased susceptibility to infections and other complications. Accurate, prompt diagnosis of IEI is crucial for treatment plan and prognostication. In this study, clinical utility of clinical exome sequencing (CES) for diagnosis of IEI was evaluated. For 37 Korean patients with suspected symptoms, signs, or laboratory abnormalities associated with IEI, CES that covers 4,894 genes including genes related to IEI was performed. Their clinical diagnosis, clinical characteristics, family history of infection, and laboratory results, as well as detected variants, were reviewed. With CES, genetic diagnosis of IEI was made in 15 out of 37 patients (40.5%). Seventeen pathogenic variants were detected from IEI-related genes, BTK, UNC13D, STAT3, IL2RG, IL10RA, NRAS, SH2D1A, GATA2, TET2, PRF1, and UBA1, of which four variants were previously unreported. Among them, somatic causative variants were identified from GATA2, TET2, and UBA1. In addition, we identified two patients incidentally diagnosed IEI by CES, which was performed to diagnose other diseases of patients with unrecognized IEI. Taken together, these results demonstrate the utility of CES for the diagnosis of IEI, which contributes to accurate diagnosis and proper treatments.

Clinical and Genetic Characteristics of Patients with Unexplained Intellectual Disability/Developmental Delay without Epilepsy.

Introduction: Global developmental delay (DD), intellectual disability (ID), and autism spectrum disorder (ASD) are mainly evaluated under the neurodevelopmental disorder framework. In this study, we aimed to determine the genetic diagnosis yield using step-by-step genetic analysis in 38 patients with unexplained ID/DD and/or ASD. Methods: In 38 cases (27 male, 11 female) with unexplained ID/DD and/or ASD, chromosomal microarray (CMA) analysis, clinical exome sequencing (CES), and whole-exome sequencing (WES) analysis were applied, respectively. Results: We found a diagnostic rate of only CMA analysis as 21% (8/38) presenting 8 pathogenic and likely pathogenic CNVs. The rate of patients diagnosed with CES/WES methods was 32.2% (10/31). When all pathogenic and likely pathogenic variants were evaluated, the diagnosis rate was 44.7% (17/38). A dual diagnosis was obtained in a case with 16p11.2 microduplication and de novo SNV. We identified eight novel variants: TUBA1A (c.787C>G), TMEM63A (c.334-2A>G), YY1AP1 (c.2051_2052del), ABCA13 (c.12064C>T), ABCA13 (c.13187G>A), USP9X (c.1189T>C), ANKRD17 (c.328_330dup), and GRIA4 (c.17G>A). Conclusion: We present diagnostic rates of a complementary approach to genetic analysis (CMA, CES, and WES). The combined use of genetic analysis methods in unexplained ID/DD and/or ASD cases has contributed significantly to diagnosis rates. Also, we present detailed clinical characteristics to improve genotype-phenotype correlation in the literature for rare and novel variants.