BACKGROUND: 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).
CONCLUSIONS: 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.

BACKGROUND: Neonatal diabetes mellitus (NDM) is a rare non-immunological monogenic disorder characterized by hyperglycemic conditions primarily occurring within the first 6 months of life. The majority of cases are attributed to pathogenic variants in genes affecting beta-cell survival, insulin regulation, and secretion. This study aims to investigate the genetic landscape of NDM in Iran.
METHODS: We recruited a total of 135 patients who were initially diagnosed with diabetes at <12 months of age in Iran and referred to pediatric endocrinology clinics across the country. These patients underwent genetic diagnostic tests conducted by the Exeter Molecular Genetics Laboratory in the UK. The pathogenic variants identified were sorted and described based on type, pathogenicity (according to ACMG/AMP criteria), novelty, and the affected protein domain.
RESULTS: Genetic defects were identified in 93 probands, presenting various pathogenic abnormalities associated with NDM and its associated syndromes. 76% of the patients were born as a result of consanguineous marriage, and a familial history of diabetes was found in 43% of the cases. A total of 58 distinct variants in 14 different genes were discovered, including 20 variants reported for the first time. Causative variants were most frequently identified in EIF2AK3, KCNJ11, and ABCC8, respectively. Notably, EIF2AK3 and ABCC8 exhibited the highest number of novel variants.
CONCLUSIONS: These findings provide valuable insights into the genetic landscape of NDM in the Iranian population and contribute to the knowledge of novel pathogenic variants within known causative genes.

UNASSIGNED: Obesity is a serious health problem, that progressively affects individuals\' lives with comorbidities involving heart disease, stroke, and diabetes mellitus. Since its prevalence increases particularly in children under age-of-five years, its genetic and environmental causes should be determined for prevention and control of the disease. This study aimed to detect underlying genetic risk factors in a family with an exclusively breastfed obese infant.
UNASSIGNED: A three-generation family was recruited to be evaluated for obesity. Detailed examinations along with body mass indexcalculations were performed on available family members. Whole exome sequencing was performed on 7-month-oldobese infant utilizing Illumina-NextSeq550. Bioinformatic analyses were performed on the Genomize SEQ platform with variant filtering at minor allele frequencies (MAF)<1% for all normal populations. Sanger sequencing was applied in variant confirmation and family segregation.
UNASSIGNED: Neuro-motor developmental features were normal and genetic syndromes were excluded from the index. Early-onset severe obesity (4.25SDS weight-for-height) was obvious in index case, where his father and grandmother were also obese (BMIs: 38.1kg/m2 and 31.3kg/m2, respectively). WES analysis revealed deleterious variants in SH2B1, PDE11A, ADCY3, and CAPN10 genes previously associated with obesity. All variants were evaluated as novel candidates for obesity except PDE11A and family segregation confirmed paternal inheritance.
UNASSIGNED: This study confirmed the paternal inheritance of all potentially deleterious obesity-related variants. The cumulative effect of individual variants might explain the obesity phenotype in this family. The infant is recommended to be under periodic follow-up due to increased risk for later childhood obesity.

OBJECTIVE: To investigate the clinical features, ALDH5A1 gene variations, treatment, and prognosis of patients with succinic semialdehyde dehydrogenase (SSADH) deficiency.
METHODS: This retrospective study evaluated the findings in 13 Chinese patients with SSADH deficiency admitted to the Pediatric Department of Peking University First Hospital from September 2013 to September 2023.
RESULTS: Thirteen patients (seven male and six female patients; two sibling sisters) had the symptoms aged from 1 month to 1 year. Their urine 4-hydroxybutyrate acid levels were elevated and were accompanied by mildly increased serum lactate levels. Brain magnetic resonance imaging (MRI) showed symmetric abnormal signals in both sides of the globus pallidus and other areas. All 13 patients had psychomotor retardation, with seven showing epileptic seizures. Among the 18 variants of the ALDH5A1 gene identified in these 13 patients, six were previously reported, while 12 were novel variants. Among the 12 novel variants, three (c.85_116del, c.206_222dup, c.762C > G) were pathogenic variants; five (c.427delA, c.515G > A, c.637C > T, c.755G > T, c.1274T > C) were likely pathogenic; and the remaining four (c.454G > C, c.479C > T, c.1480G > A, c.1501G > C) were variants of uncertain significance. The patients received drugs such as L-carnitine, vigabatrin, and taurine, along with symptomatic treatment. Their urine 4-hydroxybutyric acid levels showed variable degrees of reduction.
CONCLUSIONS: A cohort of 13 cases with early-onset SSADH deficiency was analyzed. Onset of symptoms occurred from 1 month to 1 year of age. Twelve novel variants of the ALDH5A1 gene were identified.

UNASSIGNED: Familial hemophagocytic lymphohistiocytosis (FHLH) is an inherited life-threatening disease. Five types are identified, with the addition of congenital immunodeficiency syndromes in which HLH is a typical manifestation. The literature on this disease is very scarce in the Middle East, with only a few scattered reports.
UNASSIGNED: We report detailed demographic, clinical, and genomic data from 28 patients diagnosed with primary and familial HLH over the last decade in Qatar. An evaluation was performed of allele frequencies of deleterious variants from 12 primary and familial HLH causative genes on the Qatar Genome Programme (QGP) cohort of 14,669 Qatari individuals.
UNASSIGNED: The genetic diagnosis was obtained in 15 patients, and four novel mutations in Perforin 1 (PRF1), UNC13D, LYST, and RAB27A genes were found. We identified 22,945 low/high/moderate/modifier impact variants significantly enriched in the QGP in those 12 genes. The variants rs1271079313 in PRF1 and rs753966933 in RAB27A found in our patient cohort were significantly more prevalent in the QGP compared to the Genome Aggregation Database (gnomAD) database, with a high carrier frequency in the Qatari population.
UNASSIGNED: We established the first primary and familial HLH Registry in the Gulf Region and identified novel possibly pathogenic variants present at higher frequency in the Qatari population, which could be used for screening purposes. Raising awareness about primary and familial HLH and implementing screening activities in the Qatari highly inbred population could stem into more comprehensive premarital and prenatal evaluations and faster diagnosis.

Background: Wolfram syndrome (WFS) is an autosomal recessive disorder that often leads to diabetes, optic atrophy, and sensorineural hearing loss. The aim of this study was to determine the clinical characteristics and the genetic cause of the first two Moroccan families presenting with WFS. Methods: The clinical features of five members of two WFS families were evaluated. Whole-exome sequencing was conducted to explore the underlying genetic cause in the affected patients. Results: Two homozygous variants in the WFS1 gene were identified, each in one of the two families studied: a missense c.1329C>G variant (p.Ser443Arg) and a nonsense mutation c.1113G>A (p.Trp371Ter). These variants affected conserved amino acid residues, segregated well in the two families, and are absent from genetic databases and in controls of Moroccan origin. Bioinformatics analysis classified the two variants as pathogenic by in silico tools and molecular modeling. Conclusion: Our study identified for the first time two variants in Moroccan patients with WFS that extends the mutational spectrum associated with the disease.

OBJECTIVE: Dentinogenesis imperfecta (DI) is an inherited dentin defect and may be isolated or associated with disorders such as osteogenesis imperfecta, odontochondrodysplasia Ehler-Danlos and others. Isolated DI is caused mainly by pathogenic variants in DSPP gene and around 50 different variants have been described in this gene. Herein, we report on 19 patients from two unrelated Egyptian families with isolated DI. Additionally, we focused on genetic counselling of the two families.
METHODS: The patients were examined clinically and dentally. Panoramic X-rays were done to some patients. Whole exome sequencing (WES) and Sanger sequencing were used.
RESULTS: WES revealed two new nonsense variants in DSPP gene, c.288T > A (p.Tyr96Ter) and c.255G > A (p.Trp85Ter). Segregation analysis by Sanger sequencing confirmed the presence of the first variant in all affected members of Family 1 while the second variant was confirmed to be de novo in the patient of Family 2.
CONCLUSIONS: Our study extends the number of DSPP pathogenic variants and strengthens the fact that DSPP is the most common DI causative gene irrespective of patients\' ethnicity. In addition, we provide insights on genetic counseling issues in patients with inherited DSPP variants taking into consideration the variable religion, culture and laws in our society.

Glycogen storage diseases (GSDs) are a group of rare inherited metabolic disorders characterized by clinical, locus, and allele heterogeneity. This study aims to investigate the phenotype and genotype spectrum of GSDs in a cohort of 14 families from Iran using whole-exome sequencing (WES) and variant analysis. WES was performed on 14 patients clinically suspected of GSDs. Variant analysis was performed to identify genetic variants associated with GSDs. A total of 13 variants were identified, including six novel variants, and seven previously reported pathogenic variants in genes such as AGL, G6PC, GAA, PYGL, PYGM, GBE1, SLC37A4, and PHKA2. Most types of GSDs observed in the cohort were associated with hepatomegaly, which was the most common clinical presentation. This study provides valuable insights into the phenotype and genotype spectrum of GSDs in a cohort of Iranian patients. The identification of novel variants adds to the growing body of knowledge regarding the genetic landscape of GSDs and has implications for genetic counseling and future therapeutic interventions. The diverse nature of GSDs underscores the need for comprehensive genetic testing methods to improve diagnostic accuracy. Continued research in this field will enhance our understanding of GSDs, ultimately leading to improved management and outcomes for individuals affected by these rare metabolic disorders.

UNASSIGNED: Molecular diagnosis of cystic fibrosis (CF) is challenging in Mexico due to the population\'s high genetic heterogeneity. To date, 46 pathogenic variants (PVs) have been reported, yielding a detection rate of 77%. We updated the spectrum and frequency of PVs responsible for this disease in mexican patients.
UNASSIGNED: We extracted genomic DNA from peripheral blood lymphocytes obtained from 297 CF patients and their parents. First, we analyzed the five most frequent PVs in the Mexican population using PCR-mediated site-directed mutagenesis. In patients with at least one identified allele, CFTR sequencing was performed using next-generation sequencing tools and multiplex ligation-dependent probe amplification. For variants not previously classified as pathogenic, we used a combination of in silico prediction, CFTR modeling, and clinical characteristics to determine a genotype-phenotype correlation.
UNASSIGNED: We identified 95 PVs, increasing the detection rate to 87.04%. The most frequent variants were p.(PheF508del) (42.7%), followed by p.(Gly542*) (5.6%), p.(Ser945Leu) (2.9%), p.(Trp1204*) and p.(Ser549Asn) (2.5%), and CFTRdel25-26 and p.(Asn386Ilefs*3) (2.3%). The remaining variants had frequencies of <2.0%, and some were exclusive to one family. We identified 10 novel PVs localized in different exons (frequency range: 0.1-0.8%), all of which produced structural changes, deletions, or duplications in different domains of the protein, resulting in dysfunctional ion flow. The use of different in silico software and American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) criteria allowed us to assume that all of these PVs were pathogenic, causing a severe phenotype.
UNASSIGNED: In a highly heterogeneous population, combinations of different tools are needed to identify the variants responsible for CF and enable the establishment of appropriate strategies for CF diagnosis, prevention, and treatment.

BACKGROUND: SLCO1B1 plays an important role in mediating hepatic clearance of many different drugs including statins, angiotensin-converting enzyme inhibitors, chemotherapeutic agents and antibiotics. Several variants in SLCO1B1 have been shown to have a clinically significant impact, in relation to efficacy of these medications. This study provides a comprehensive overview of SLCO1B1 variation in Saudi individuals, one of the largest Arab populations in the Middle East.
METHODS: The dataset of 11,889 (9,961 exomes and 1,928 pharmacogenetic gene panel) Saudi nationals, was used to determine the presence and frequencies of SLCO1B1 variants, as described by the Clinical Pharmacogenetic Implementation Consortium (CPIC).
RESULTS: We identified 141 previously described SNPs, of which rs2306283 (50%) and rs4149056 (28%), were the most common. In addition, we observed six alleles [*15 (24.7%) followed by *20 (8.04%), *14 (5.86%), *5 (3.84%), *31 (0.21%) and *9 (0.03%)] predicted to be clinically actionable. Allele diplotype to phenotype conversion revealed 41 OATP1B1 diplotypes. We estimated the burden of rare, and novel predicted deleterious variants, resulting from 17 such alterations.
CONCLUSIONS: The data we present, from one of the largest Arab cohorts studied to date, provides the most comprehensive overview of SLCO1B1 variants, and the subsequent OATP1B1 activity of this ethnic group, which thus far remains relatively underrepresented in available international genomic databases. We believe that the presented data provides a basis for further clinical investigations and the application of personalized statin drug therapy guidance in Arabs.