Investigation of genotype-phenotype and familial features of Turkish dystrophinopathy patients.

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive allelic muscle diseases caused by dystrophin gene mutations. Eight hundred thirty-seven patients admitted between 1997 and 2022 were included in the study. Two hundred twenty patients were analyzed by multiplex PCR (mPCR) alone. Five hundred ninety-five patients were investigated by multiplex ligation-dependent probe amplification (MLPA), and 54 patients were examined by sequencing. Deletion was detected in 60% (132/220) of the cases in the mPCR group only and in 58.3% (347/595) of the cases with MLPA analysis. The rates of deletion and duplication were 87.7% and 12.3%, respectively, in the MLPA analysis. Single exon deletions were the most common mutation type. The introns 43-55 (81.8%) and exons 2-21 (13.1%) regions were detected as hot spots in deletions. It was determined that 89% of the mutations were suitable for exon skipping therapy. The reading frame rule did not hold in 7.6% of D/BMD cases (17/224). We detected twenty-five pathogenic/likely pathogenic variants in sequencing, five of which were novel variants. Nonsense mutation was the most common small mutation (44%). 21% of DMD patients were familial. We detected germline mosaicism in four families (4.3%) in the large rearrangement group and one gonosomal mosaicism in a family with a nonsense mutation. This is the largest study examining genotype and phenotype data in Turkish D/BMD families investigated by MLPA analysis. The reading frame hypothesis is not valid in all cases. Sharing the genotype and phenotype characteristics of these cases in the literature will shed light on the molecular structure of DMD and guide gene therapy research. In genetic counseling, carrier screening in the family and possible gonadal mosaicism should be emphasized.

Genetic, serological and clinical evaluation of childhood myasthenia syndromes- single center subgroup analysis experience in Turkey.

BACKGROUND: Congenital myasthenic syndrome is a disease that occurs due to several types such as mutations in different pre-synaptic, synaptic, post-synaptic proteins and, glycosylation defects associated with congenital myopathy. Juvenile myasthenia gravis is an autoimmune condition usually caused by antibodies targeting the acetylcholine receptor. AIMS: Our objective is to conduct an analysis on the subgroup traits exhibited by patients who have been diagnosed with congenital myasthenic syndrome and juvenile myasthenia gravis, with a focus on their long-term monitoring and management. METHODS: This study was conducted on children diagnosed with myasthenia gravis, who were under the care of Dokuz Eylul University's Department of Pediatric Neurology for a period of ten years. RESULTS: A total of 22 (12 congenital myasthenic syndrome, 10 juvenile myasthenia gravis) patients were identified. Defects in the acetylcholine receptor (6/12) were the most common type in the congenital myasthenic syndrome group. Basal-lamina-related defects (5/12) were the second most prevalent. One patient had a GFPT1 gene mutation (1/12). Patients with ocular myasthenia gravis (n = 6) exhibited milder symptoms. In the generalized myasthenia gravis group (n = 4), specifically in postpubertal girls, a more severe clinical progression was observed, leading to the implementation of more aggressive treatment strategies. CONCLUSION: This study highlights that clinical recognition of congenital myasthenic syndrome and knowledge of related genes will aid the rapid diagnosis and treatment of these rare neuromuscular disorders. Findings in the juvenile myasthenia gravis group demonstrate the impact of pubertal development and the need for timely and appropriate active therapy, including thymectomy, to improve prognosis.

Investigation of different genomic variants in familial Mediterranean fever cases with monoallelic MEFV mutation.

OBJECTIVES: Familial Mediterranean Fever (FMF) is an inflammatory disease characterised by periodic fever and concurrent episodes of serous membrane inflammation. FMF is considered to be inherited in autosomal recessive manner and biallelic mutations in the MEFV gene are associated with the disease. However, approximately 20-25% of patients only have a single mutation in MEFV gene, which creates confusion in differential diagnosis of many patients. This study aimed to reveal rare variants that may act in conjunction with the single pathogenic MEFV variant in the pathogenesis of FMF. METHODS: We performed whole exome sequencing in 17 individuals from 5 different families who were diagnosed according to the clinical criteria, responded positively to colchicine treatment, but had no biallelic MEFV mutation. RESULTS: A disease-causing variant or a common affected cellular pathway that was shared in all index cases was not detected. When cases were examined individually, two de novo variants were identified in the BIRC2 and BCL10 genes, both of which play a role in inflammatory pathways. Functional studies are needed to confirm the physiopathological relationship of these genes with FMF. CONCLUSIONS: This study is one of the most extensive aetiological researches in FMF cases with monoallelic MEFV mutation. We have shown that genotype-phenotype correlation in these cases may not be established by rare genetic variants and discussed underlying causes. Clinical criteria with emphasis on colchicine response and family history should be the main tool and genetic results should only be used for support in FMF diagnosis.

Spondyloepimetaphyseal dysplasia-Maroteaux type due to dominant TRPV4 mutation: expanding the phenotype with a case report.

INTRODUCTION: Dominant pathogenic mutations in the TRPV4 gene give rise to a wide spectrum of abnormal phenotypes, including bone dysplasia as well as spinal muscular atrophy and hereditary motor and sensory neuropathy. Spondyloepimetaphyseal dysplasias (SEMDs) are autosomal dominant skeletal dysplasias characterized by mild epiphyseal dysplasia, flared metaphyses, prominent joints, spondyler dysplasia, and brachydactyly with various carpal, metacarpal, and finger malformations. CASE PRESENTATION: We present a boy who has the clinical and radiological signs of SEMD-M with a dominant TRPV4 mutation. He also has some striking findings that have not been seen in these patients before, and they may be able to provide assistance to medical professionals in the process of diagnosis.These include a shorter distance between his lumbar vertebrae, congenital contractures, and an arachnoid cyst.

Hemoglobin A1C can differentiate subjects with GCK mutations among patients suspected to have MODY.

OBJECTIVES: The aim of this study is to determine the clinical and molecular characteristics enabling differential diagnosis in a group of Turkish children clinically diagnosed with MODY and identify the cut-off value of HbA1c, which can distinguish patients with GCK variants from young-onset type 1 and type 2 diabetes. METHODS: The study included 49 patients from 48 unrelated families who were admitted between 2018 and 2020 with a clinical diagnosis of MODY. Clinical and laboratory characteristics of the patients at the time of the diagnosis were obtained from hospital records. Variant analysis of ten MODY genes was performed using targeted next-generation sequencing (NGS) panel and the variants were classified according to American Collage of Medical Genetics and Genomics (ACMG) Standards and Guidelines recommendations. RESULTS: A total of 14 (28%) pathogenic/likely pathogenic variants were detected among 49 patients. 11 variants in GCK and 3 variants in HNF1A genes were found. We identified four novel variants in GCK gene. Using ROC analysis, we found that best cut-off value of HbA1c at the time of diagnosis for predicting the subjects with a GCK variant among patients suspected to have MODY was 6.95% (sensitivity 90%, specificity 86%, AUC 0.89 [95% CI: 0.783-1]). Most of the cases without GCK variant (33/38 [86%]) had an HbA1c value above this cutoff value. We found that among participants suspected of having MODY, family history, HbA1c at the time of diagnosis, and not using insulin therapy were the most differentiating variables of patients with GCK variants. CONCLUSIONS: Family history, HbA1c at the time of diagnosis, and not receiving insulin therapy were found to be the most distinguishing variables of patients with GCK variants among subjects suspected to have MODY.

Blended Phenotype of Pelger-Huet Anomaly with Osteochondroma and Autosomal Recessive Deafness with Enlarged Vestibular Aqueduct.

Pelger-Huet anomaly (PHA) is a benign hematological anomaly that is characterized by impaired lobulation of neutrophils with a coarse nuclear chromatin. Skeletal abnormalities may accompany this anomaly. Autosomal recessive deafness-4 (DFNB4) with enlarged vestibular aqueduct (EVA) comprises a phenotypic spectrum of sensorineural hearing loss (SNHL). We report a case with SNHL, multiple skeletal anomalies including osteochondroma, developmental delay, and PHA. Molecular studies revealed a heterozygous pathogenic variant in the LBR gene and a homozygous likely pathogenic variant in the SLC26A4 gene. Due to these 2 variants, he was diagnosed with PHA and DFNB4 with EVA. If goiter develops, DFNB4 with EVA is named Pendred syndrome (PDS), so the patient will be followed up for this condition, and in the current literature, there is no case with PDS and PHA co-existence either. PHA may be accompanied by multiple skeletal abnormalities. In our case, there is also concomitance with osteochondroma. Although these are independent and distinct diagnoses, we present this case due to the concomitance of these situations.

Autoimmune/autoinflammatory syndrome induced by adjuvants after multi-component meningococcal serogroup B vaccination in a 7-year-old girl: a case report.

BACKGROUND: Vaccines, which make it possible to be protected from many life-threatening infectious diseases, have been used safely and effectively for years. Most vaccines used today contain a variety of adjuvants and exogenous proteins. Severe reactions, in addition to transient and self-limiting mild reactions, mostly caused by these components, have been reported. The effects of vaccine adjuvants on the pathogenesis of immunemediated diseases are still under investigation. The syndrome called Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) has been defined in the literature. CASE: We found a novel mutation of autoinflammatory diseases in the genetic analysis of our patient. The patient developed symptoms of prolonged fever, rash, arthritis and serositis after multicomponent serogroup B meningococcal (Bexsero®) vaccination, without a previously known rheumatic disease. In the presence of clinical findings in our patient, the diagnostic criteria of ASIA syndrome were met. CONCLUSION: To the best of our knowledge, this is the first case report of a patient diagnosed with the autoinflammatory disease with a novel mutation after Bexsero® vaccination. We consider that genetic examinations will be useful in patients with a systemic vaccine reaction in the presence of ASIA when diagnostic criteria are met.

De Novo PORCN and ZIC2 Mutations in a Highly Consanguineous Family.

We present a Turkish family with two cousins (OC15 and OC15b) affected with syndromic developmental delay, microcephaly, and trigonocephaly but with some phenotypic traits distinct between them. OC15 showed asymmetrical skeletal defects and syndactyly, while OC15b presented with a more severe microcephaly and semilobal holoprosencephaly. All four progenitors were related and OC15 parents were consanguineous. Whole Exome Sequencing (WES) analysis was performed on patient OC15 as a singleton and on the OC15b trio. Selected variants were validated by Sanger sequencing. We did not identify any shared variant that could be associated with the disease. Instead, each patient presented a de novo heterozygous variant in a different gene. OC15 carried a nonsense mutation (p.Arg95*) in PORCN, which is a gene responsible for Goltz-Gorlin syndrome, while OC15b carried an indel mutation in ZIC2 leading to the substitution of three residues by a proline (p.His404_Ser406delinsPro). Autosomal dominant mutations in ZIC2 have been associated with holoprosencephaly 5. Both variants are absent in the general population and are predicted to be pathogenic. These two de novo heterozygous variants identified in the two patients seem to explain the major phenotypic alterations of each particular case, instead of a homozygous variant that would be expected by the underlying consanguinity.

Serum motilin levels and motilin gene polymorphisms in children with functional constipation.

BACKGROUND: Functional constipation is an important clinical problem among chidren all over the world. Its main cause is not completely understood. Motilin is a gastrointestinal hormone that increases intestinal motility. In this study, we aimed to investigate the serum motilin levels and its relationship with stool consistency and motilin gene polymorphisms in constipated children. METHODS: In this study we investigated 91 constipated patients (mean age 6.84±3.55 years) and 100 healthy controls (mean age 7.78±4.25 years). Serum motilin levels were assessed by sandwich enzyme-linked immunosorbent assay. rs2281820 (c.44 C>T) and rs2281818 (c.66 C>T) mutations were evaluated for motilin gene polymorphisms. RESULTS: Serum motilin levels were significantly lower in constipated children than healthy controls (6.20±7.86 vs. 11.54±17.89 pg/mL, respectively, P=0.008). Serum motilin levels were significantly correlated with Bristol stool scale rate (r=0.193, P=0.011) in whole study group, but in the constipation group there was no significant correlation (r=-0.072, P=0.528). There were no differences in terms of presence or distribution of the polymorphisms of rs2281820 (c.44 C>T) and rs2281818 (c.66 C>T) in both groups. There was not a significant difference between different polymorphism groups regarding serum motilin concentrations in whole study group and also in both of the study groups. CONCLUSIONS: This study indicated for the first time that serum motilin levels decreased in constipated children. Further studies are needed to clarify whether motilin or motilin gene polymorphisms has a role in pathogenesis of functional constipation.

Investigation of the most common clinical and imaging findings and the role of tubulin genes in the etiology of malformations of cortical development

Background and aim: The number of reports on the role of tubulin gene mutations (TUBA1A, TUBB2B, and TUBB3) in etiology of malformations of cortical development has peaked in recent years. We aimed to determine tubulin gene defects on a patient population with simple and complex malformations of cortical development, and investigate the relationship between tubulin gene mutations and disease phenotype. Materials and methods: We evaluated 47 patients with simple or complex malformations of cortical development, as determined by radiological examination, for demographic features, clinical findings and mutations on TUBA1A, TUBB2B, and TUBB3 genes. Results: According to the magnetic resonance imaging findings, 19 patients (40.5%) had simple malformations of cortical development and 28 (59.5%) patients had complex malformations of cortical development. Focal cortical dysplasia was the most common simple malformation, lissencephaly was the most common coexisting cortical malformation, and corpus callosum anomalies were the most common coexisting extracortical neurodevelopmental abnormalities. None of the patients had genetic alterations on TUBA1A, TUBB2B, and TUBB3 genes causing protein dysfunction. On the other hand, the frequencies of some polymorphisms were higher when compared to the literature. Conclusion: It is crucial to identify the etiology in patients with malformations of cortical development in order to provide appropriate genetic counseling and prenatal diagnosis. We consider that multicenter studies with higher patient numbers and also including other malformations of cortical development-related genes are required to determine underlying etiological factors of malformations of cortical development patients.

Schizophrenia in microcephalic osteodysplastic primordial dwarfism type II syndrome: supporting evidence for an association between the PCNT gene and schizophrenia.

Schizophrenia is a genetically complex disease that is related to neurodevelopmental abnormalities. Several genetic polymorphisms and genetic syndromes associated with neurodevelopmental processes have been linked to schizophrenia. In this case report, we present a case with an association between microcephalic osteodysplastic primordial dwarfism type II and schizophrenia. Microcephalic osteodysplastic primordial dwarfism type II syndrome is a rare, autosomal recessive disease that occurs as a result of the mutations in the pericentrin (PCNT) gene that are responsible for cell cycle and division. In this report, we discuss the possible association between the PCNT gene and schizophrenia.

Phenotypic spectrum of CHARGE syndrome based on clinical characteristics

Background/aim: CHARGE syndrome is a rare autosomal dominant disease with multiple congenital anomalies and cognitive impairment, which is caused by mutations in the CHD7 gene. This study aimed to disclose the mild end of the phenotypic spectrum of CHARGE syndrome, which has a highly variable expressivity. Materials and methods: Twenty-one patients who had at least one of the major symptoms of CHARGE syndrome (coloboma, choanal atresia, characteristic ear anomalies, semicircular canal hypoplasia, and cranial nerve anomalies) were included in the study. All patients were tested for karyotype analysis and CHD7 gene mutation/deletion. Results: In the study population, 6 different mutations were detected in 5 patients, and 2 different polymorphisms were detected in the CHD7 gene in 3 patients. MLPA analysis of all coding exons of the CHD7 gene revealed no pathogenic deletion/duplication. Conclusion: CHARGE syndrome should be considered as a differential diagnosis to detect the mild end of the spectrum, even if the patient does not fit the criteria.

Two Cases with Ring Chromosome 13 at either End of the Phenotypic Spectrum.

Ring chromosome 13 is a rare genetic condition with an incidence of 1/58,000 in live births. Major clinical features of patients with ring chromosome 13 include growth and developmental retardation, microcephaly, facial dysmorphism, ambiguous genitalia, anal atresia, eye malformations, retinoblastoma, and hand, foot, and toe abnormalities. The severity of the phenotype depends on the amount of genetic material lost during ring chromosome formation. Here, we report 2 cases with ring chromosome 13 at either end of the phenotypic spectrum.

Assessment of sleep problems in children with familial Mediterranean fever.

AIMS: This study aimed to investigate sleep patterns, sleep disturbances and possible factors that are associated with sleep disturbances among children with familial Mediterranean fever (FMF). PATIENTS AND METHODS: Fifty-one patients with FMF and 84 age- and sex-matched healthy controls were enrolled in the study. The patients who had an attack during the last 2 weeks were not included. Demographic data, FMF symptoms, disease duration, dose of colchicine, disease severity score, number of attacks in the last year, MEFV mutation and serum C-reactive protein (CRP) levels were recorded for each patient. A Children's Sleep Habits Questionnaire was performed. RESULTS: The total sleep scores of the patients with FMF were significantly higher than the control group. Total sleep durations were similar between FMF patients and controls. Children with FMF had significantly higher scores regarding sleep-onset delay, sleep anxiety, night wakings and sleep-disordered breathing when compared to healthy controls. There was a significant positive correlation between number of attacks in the last year and sleep onset delay, night wakings and sleep disordered-breathing. Disease severity score and CRP levels were not associated with any of the subscale scores. The patients with exertional leg pain had significantly higher total sleep scores than the ones without. Furthermore, patients with exertional leg pain had significantly higher subscale scores regarding sleep onset delay, parasomnias and sleep-disordered breathing. CONCLUSION: This study showed for the first time that children with FMF had more sleep disturbances than their healthy peers. Higher numbers of attacks and exertional leg pain were associated with poor sleep quality. In conclusion, this study underlines the need to assess and manage sleep problems in children with FMF.

Identification of a novel frameshift heterozygous deletion in exon 8 of the PAX6 gene in a pedigree with aniridia.

Aniridia is a congenital, panocular abnormality which is characterized by partial or complete absence of iris and various degrees of iris hypoplasia. Mutations in the PAX6 gene are found in ~90% of cases with aniridia. The human PAX6 gene is located at chromosome 11p13 and encodes a transcriptional regulator that has crucial roles in the development of the eyes, central nervous system and pancreatic islets. The present study performed a clinical and genomic analysis of two families containing multiple cases of aniridia. All exons of the PAX6 gene of the probands were sequenced using the Sanger sequencing technique. A heterozygous non­stop mutation in exon 14 was identified in the first family, which has been previously reported for a different ophthalmological pathology. This mutation causes on­going translation of the mRNA into the 3'­untranslated region. In the second family, a novel frameshift heterozygous deletion in exon 8 was identified.

A novel mutation in the mitochondrial DNA cytochrome b gene (MTCYB) in a patient with Prader Willi syndrome.

In recent years, it has been suggested that defects in energy metabolism may accompany Prader Willi syndrome. Mutations in the mitochondrial cytochrome b gene have been commonly associated isolated mitochondrial myopathy and exercise intolerance, rarely with multisystem disorders. The authors describe a novel mutation (mt. 15209T>C) in mitochondrial cytochrome b gene in a 2-year-old girl with Prader-Willi syndrome with a clinical history of lactic acidosis attacks, renal sodium loss, hepatopathy, progressive cerebral atrophy, and sudden death. The authors suggest that atypical clinical findings in patients with Prader-Willi syndrome should direct the physician to search for a mitochondrial disease.

Lack of association of childhood partial epilepsy with brain derived neurotrophic factor gene.

Brain-derived factor (BDNF) is a member of neurotrophin family and is localized and upregulated in areas implicated in epileptogenesis. Several lines of evidence make the BDNF gene a plausible candidate gene for predisposition to epilepsy. In this study, we tested that BDNF might be involved in the etiology of childhood PE. To assess whether BDNF gene C270T polimorphism could be implicated in vulnerability to PE, we conducted a case-control association analysis (112 partial epileptic and 100 controls) in Turkish children. Epileptic children were divided into two groups: 1--idiopathic (n = 85) and 2--symptomathic epilepsy (n = 27). There was no significant difference in genotypic distribution and allelic frequencies of the BDNF gene C270T polimorphism between the PE and control groups. However, the BDNF gene TT genotype was more frequently seen in the epileptic children (15 versus 11 patients, resp.). Interestingly, in the epilepsy group, both two children with TT genotype have posttraumatic epilepsy. The data indicate a possible association with the 270T genotype of the BDNF gene with a posttraumatic epilepsy. To draw any conclusion, further studies using larger sample sizes should be carried out in various ethnic populations in childhood epilepsies.