Identification of PCDH19 Gene Mutations/Deletions in Patients with Early Onset Epilepsy

Background and Aims:

PCDH19 gene, which encodes protocadherin 19, is associated with epilepsy and intellectual disability, mainly in affected females. The clinical manifestations are heterogeneous and the main features include early onset seizure, generalized or focal seizures sensitive to fever, and brief seizures occurring in clusters. The disorders exhibit a unique and unusual X-linked pattern of expression. We aimed to investigate PCDH19 mutations/deletions in patients with epilepsy and describe the clinical/molecular features.

Methods:

PCDH19 gene was analyzed in 35 Turkish female patients from 34 families with early-onset epilepsy via direct sequencing and multiplex ligation-dependent probe amplification analysis. Additionally, array comparative genomic hybridization analysis was performed in patients with whole gene deletion.

Results:

We identified 2 different heterozygous mutations in 2 unrelated probands (5. 7%) which were located in exon 1. Additionally, whole gene deletions were detected in dizygotic twin girls (5. 7%), who had distinct clinical features and the deletion was inherited from the unaffected father. The second twin suffered more severe clinical manifestations including autistic features, behavioral problems, mild-moderate mental retardation and seizures, which were under control with multidrug regimen when compared with the first twin.

Conclusion:

PCDH19 is a major causative gene in patients with epilepsy and further data is required to gain a better understanding of phenotype-genotype correlation. In addition to gene sequencing, deletion/duplication analysis will improve the molecular diagnosis in patients with clinical findings.

A toddler with a novel LEPR mutation

There are numerous causes, such as environmental factors, medications, endocrine disorders, and genetic factors, that can lead to obesity. However, severe early-onset obesity with abnormal feeding behavior, mental retardation, dysmorphic features, organ-specific developmental abnormalities, and endocrine disorders suggest a genetic etiology. Mutations in genes related to the leptin-melanocortin pathway play a key role in genetic obesity. This pathway controls hypothalamic regulation of food intake. A few cases have been reported to have mutations in leptin (LEP) or leptin receptor (LEPR) genes. The cases had severe early-onset obesity, hyperphagia, and additional features, such as altered immune function, hypogonadism, and hypothyroidism. We present a 3-year-old male patient with severe early-onset obesity whose genetic analysis revealed a homozygous, novel, and pathogenic variant (c.1603+2T>C) in LEPR.

Genetic Evaluation of Common Neurocutaneous Syndromes

The neurocutaneous syndromes are a group of multisystem disorders that affect the skin and central nervous system. Neurofibromatosis 1, neurofibromatosis 2, tuberous sclerosis complex, and Sturge-Weber syndrome are the four major neurocutaneous disorders that mainly present in childhood. In this review, we discuss the clinical findings and genetic diagnosis, related genes/pathways and genotype-phenotype correlations of these four neurocutaneous syndromes.

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.

The ASXL1 mutation p.Gly646Trpfs*12 found in a Turkish boy with Bohring-Opitz Syndrome

In line with a recent study showing that ASXL1 mutations found in the common population cannot be ruled out as pathogenic, we have identified the ASXL1 p.Gly646Trpfs*12 mutation—present in 132 individuals in ExAC—as a very probable cause of the disease in a Bohring‐Opitz syndrome patient.

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.

Identification of an AR mutation in Klinefelter syndrome during evaluation for penoscrotal hypospadias

Genital anomalies, ranging from female genitalia to milder degrees of undervirilization, are rarely reported in Klinefelter syndrome, in which a male is classically expected to be born with male external genitalia. Though androgen insensitivity syndrome (AIS) is one of the possible pathogenic mechanisms also in Klinefelter syndrome with genital anomalies, to date the AR gene has not been analyzed in any of the published cases of Klinefelter syndrome of the milder phenotype, except for those patients presenting with a severe phenotype, such as female external genitalia.Lack of interest in considering androgen insensitivity in Klinefelter syndrome with a milder phenotype of genital anomalies may impede its identification through an accurate diagnosis. We present a 14-month-old boy with penoscrotal hypospadias, micropenis, and a ventral penile chordee abnormality who was observed to have both a 47,XXY karyotype and a known missense mutation in the ARgene that was inherited from his mother. Although it is recommended that Klinefelter syndrome be considered in the differential diagnosis of penoscrotal abnormalities, mutations in specific genes involved in androgen synthesis or responsiveness should also be investigated.

Expanding spectrum of SCN1A-related phenotype with novel mutations

Mutations in the genes encoding voltage-gated sodium channels cause a variety of epilepsy syndromes, with most of the mutations occurring in SCN1A gene. It is one of the most well-researched epilepsy genes. The SCN1A gene, which seems to be a relevant regulator of excitability of the CNS, is implicated in various epilepsy phenotypes through various genetic mechanisms ranging from common variants to rare monogenic variants. It is known that SCN1A gene is tightly linked to severe myoclonic epilepsy of infancy (SMEI). However, its phenotypic spectrum is expanding. Here, we report clinical and genetic findings of 10 patients with SCN1A mutations where two of them were found to have novel mutations. Our findings support understanding and updating knowledge on the correlation between phenotype distribution and location and type of mutations in SCN1A-related disorders.

Diagnostic Approach to Genetic Causes of Early-Onset Epileptic Encephalopathy

Epileptic encephalopathies are characterized by recurrent clinical seizures and prominent interictal epileptiform discharges seen during the early infantile period. Although epileptic encephalopathies are mostly associated with structural brain defects and inherited metabolic disorders, pathogenic gene mutations may also be involved in the development of epileptic encephalopathies even when no clear genetic inheritance patterns or consanguinity exist. The most common epileptic encephalopathies are Ohtahara syndrome, early myoclonic encephalopathy, epilepsy of infancy with migrating focal seizures, West syndrome and Dravet syndrome, which are usually unresponsive to traditional antiepileptic medication. Many of the diagnoses describe the phenotype of these electroclinical syndromes, but not the underlying causes. To date, approximately 265 genes have been defined in epilepsy and several genes including STXBP1, ARX, SLC25A22, KCNQ2, CDKL5, SCN1A, and PCDH19 have been found to be associated with early-onset epileptic encephalopathies. In this review, we aimed to present a diagnostic approach to primary genetic causes of early-onset epileptic encephalopathies.

Plasminogen activator inhibitor-1 and angiotensin converting enzyme gene polymorphisms in Turkish asthmatic children

BACKGROUND

Polymorphisms of plasminogen activator inhibitor-1 (PAI-1) and angiotensin-converting enzyme (ACE) genes have been implicated in susceptibility to asthma. In this study, we aimed to investigate whether there was any association between childhood asthma and polymorphisms of the PAI-1 and ACE genes.

METHODS

Two hundred and three Turkish children aged 5-15 years, including 102 asthmatic patients and 101 healthy control subjects were included in this study. The asthma group was divided into two groups as follows: Group I: Asthmatic children with positive family history for atopy (n=53), Group II: Asthmatic children without any family history for atopy (n=49). One hundred and twenty-eight atopic family members were also included in the study. The insertion/deletion (I/D) polymorphism of the ACE and PAI-1 4G/5G gene polymorphisms was carried out by polymerase chain reaction.

RESULTS

The prevalence of the PAI-1 4G allele was significantly greater in asthmatic children compared to control group (p<0.05, OR: 1.64 (1.11-2.43)) but there was no significant relation between ACE I/D genotypes and childhood asthma. No significant difference was detected between Groups I and II in terms of these ACE and PAI-1 genotypes and allele frequencies. No significant relationship was found between both gene polymorphisms and total serum IgE and skin prick test results.

CONCLUSION

It has been established that PAI-1 4G allele may be a genetic risk factor for childhood asthma but ACE gene I/D polymorphisms do not play a role in the development of asthma in the sample of Turkish children.

Role of apolipoprotein E in febrile convulsion

Apolipoprotein E is consistently associated with the progression of some common human neurodegenerative diseases, e.g., epilepsy. We hypothesized that genetic variations in the apolipoprotein E gene have implications for susceptibility to, and prognoses in, febrile convulsion, which plays an apparent role in the development of epilepsy. We used the polymerase chain reaction and restriction enzyme digestion to characterize variations of the apolipoprotein E gene. Sixty-nine patients with febrile convulsion (simple/complex) and a corresponding cohort of healthy patients (n = 75) were used. There was no significant difference in genotypic distribution and allelic frequencies of the apolipoprotein E gene between the febrile convulsion and control groups. Comparing subpopulations of the febrile convulsion group (patients with simple and complex febrile convulsion), we noted that no patients with the epsilon3/epsilon4 genotype had complex febrile convulsions. The apolipoprotein E epsilon3/epsilon4 genotype was more frequently seen in the simple febrile than in the complicated febrile convulsion group (9 versus 0 patients, respectively). The data indicate an association with the epsilon3/epsilon4 genotype of the apolipoprotein E gene with a milder phenotype. Although apolipoprotein E4 is not a vulnerability factor regarding febrile convulsions, it seems effective in regard to prognoses.

Growth in familial mediterranean fever: effect of attack rate, genotype and colchicine treatment

We evaluated the effect of attack frequency, homozygosity for the M694V mutation and colchicine treatment on growth in children with familial Mediterranean fever (FMF). Prepubertal patients with FMF (19 M, 14 F) were evaluated retrospectively for height SDS, weight SDS and body mass index (BMI) before and after 46.2 +/- 39.8 months of colchicine therapy. Pretreatment attack frequency and acute phase markers at diagnosis were also recorded. While acute phase markers were not correlated to anthropometric variables, attack rate was negatively, albeit insignificantly, correlated to height and weight SDS. Height SDS did not change, while BMI showed a slight but significant increase during colchicine therapy (16.2 +/- 2.6 to 17.3 +/- 3.1 kg/m2, p = 0.035). Homozygosity for M694V did not affect time from the onset of symptoms to diagnosis, anthropometric variables and acute phase markers. In conclusion, pre-treatment attack rate and anthropometric development correlated negatively. Colchicine therapy improved BMI slightly, but significantly. Homozygosity for M694V had no effect on anthropometric development.

Long-standing fever and Angelman syndrome: report of two cases

An 8-month-old girl and a 20-month-old boy who presented with motor and developmental delay and long-standing fever are presented. The patients were diagnosed as Angelman syndrome with fluorescence in situ hybridization (FISH) analysis. Despite extensive clinical and laboratory examinations, no inflammatory or infectious origin for the fever was found. It was considered that the long-standing fever observed in these cases was due to hypothalamic dysfunction for thermoregulation.

An unusual case of monosomy 18p: minor malformations with speech delay

An unusual case of monosomy 18p with molecular cytogenetic characterization of 18;21 whole arm translocation who had mild speech delay and normal motor development is presented. A 3.5-year-old boy with complaints of speech delay, open mouth and drooling saliva was the child of a 33-year-old healthy mother and 35-year-old nonconsangineous father with unremarkable prenatal history. Beside delayed speech, hyperactive movements, flat nasal bridge, prominent ears, micrognathia, hypotonia, and overriding of left 3rd the on 2nd toe were present. Cytogenetic studies revealed de novo 45,XY del (18) t(18;21)-21 karyotype, which was confirmed by fluorescence in situ hybridization (FISH).

Deletion analysis and clinical correlations in patients with Xp21 linked muscular dystrophy

We carried out molecular deletion analysis on 142 patients with Duchenne/Becker muscular dystrophy which covered 25 exons of the dystrophin gene. We also evaluated the results by comparing with the clinical findings and examples in the literature. A deletion ratio of 63.7% was achieved. Exon 46 was the most frequently affected region. Interestingly we also observed four cases with muscle promoter (Mp) region deletions which have been rarely reported in the literature.

Analyses of polymorphism for UGT1*1 exon 1 promoter in neonates with pathologic and prolonged jaundice

In this study, we investigated whether a TATA box polymorphism in the promoter of the UGT1*1 exon I, the most common detected DNA polymorphism in Gilbert's syndrome, is a contributory factor in unexplained pathologic or prolonged jaundice. 38 neonates who had unexplained pathologic jaundice, 37 neonates who had unexplained prolonged jaundice, and 35 healthy, nonjaundiced neonates were enrolled in the study. Genotypes were assigned as follows: 6/6 (homozygous for a normal allele bearing the sequence [TA](6)TAA), 7/7 (homozygous for an abnormal allele with the sequence [TA](7)TAA), and 6/7 (heterozygous with one of each allele). Of the 110 infants, 10 (9%) had 7/7, 51 (46%) had 6/7, and 49 (45%) had 6/6 genotype; the differences between the three groups were not statistically significant. Also no differences were observed among different genotypes and mean serum total bilirubin concentrations. In conclusion, we showed that TA 7/7 and TA 6/7 genotypes are not rare in our population and that the presence of these polymorphisms alone does not play a significant role in the etiology of unexplained pathologic or prolonged neonatal hyperbilirubinemia.

Congenital cardiac defects with 22q11 deletion

New cytogenetic techniques have promoted progress in determining the role of chromosomal abnormalities in the cause of congenital cardiac defects. Some patients with congenital cardiac defect have a microdeletion within chromosomal region 22q11, and a majority of them are conotruncal cardiac defects. To determine frequency in our population, we evaluated 36 patients with congenital cardiac defects, 23 of them with conotruncal cardiac defects. Microdeletion of 22q11 was detected in seven of 36 patients (19.4%), and in all deleted cases cardiac pathology was conotruncal.

Electroretinographic findings in Duchenne/Becker muscular dystrophy and correlation with genotype

PURPOSE

To correlate the electroretinography (ERG) findings in patients with Duchenne/Becker muscular dystrophy (D/BMD) with the genotype and evaluate the ERG findings in DMD carriers.

MATERIALS AND METHODS

Fifteen deletion positive patients with DMD, two deletion positive patients with BMD and six DMD carriers in two families having a positive disease history were evaluated with DNA analysis, ophthalmologic and ERG findings.

RESULTS

The mean age of the deletion positive D/BMD patients was 11.1 +/- 3.7 (range: 7-20). No abnormality was detected in the ophthalmic examination of the patients. In three out of 17 patients with D/BMD, ERG was normal whereas in 14 patients electronegative ERG was recorded in scotopic conditions. Mutational alterations observed in these three cases with normal ERG were located exceptionally at 5' hot spot; not like the others within central region. In all DMD carriers ERG findings were recorded as normal.

CONCLUSION

ERG findings in D/BMD patients may show some correlations with molecular analysis, whereas it is not useful in DMD carriers.

Amelogenesis imperfecta with growth hormone deficiency in a 12 year-old boy

Amelogenesis imperfecta (AI) is a diverse group of hereditary disorders that are characterized by a defect in the formation of the tooth enamel and a high degree of clinical diversity. X-linked, autosomal dominant and recessive inheritance have been demonstrated. Growth hormone (GH) has an effect on bone and soft tissue development. Dental and facial abnormalities associated with pituitary dwarfism have been reported, but GH deficiency with AI is very rare. We describe a 12 year-old pre-pubertal boy who was referred to our hospital with teeth deformities and growth retardation. His teeth had brown-yellow pigmented surfaces, and dental examination showed extensive enamel deficiency in his permanent teeth. He also had severe growth retardation; height SDS was -3.6. Laboratory examinations showed reduced GH levels, and he was diagnosed as having idiopathic isolated GH deficiency and AI.

Goldston syndrome: report of a case

Cerebrohepatorenal malformation is a rare familial disorder characterized by typical renal lesions combined with Dandy-Walker malformation, and congenital hepatic fibrosis. In this case report, a male premie with the diagnosis of cerebrorenal syndrome or so called Goldston syndrome is presented. Besides the rarity of this syndrome, this case is the second reported patient diagnosed prenatally.

Nonimmune hydrops fetalis and bilateral pulmonary hypoplasia in a newborn infant with nuchal vascular hamartoma

Nuchal vascular hamartoma was found in a newborn premature infant who presented with nonimmune hydrops fetalis, pulmonary hypoplasia due to bilateral pleural effusion and polyhydramnios in utero. The baby died 26 hours after birth despite maximal respiratory and circulatory support. Postmortem examination revealed a vascular hamartoma localized to the left posterolateral region of the neck. We suggest that nuchal vascular hamartoma may be associated with fetal hydrops, probably due to compromised lymph drainage.

Tricho-rhino-phalangeal syndrome type I

Tricho-rhino-phalangeal syndrome type I (TRPS I) is characterized by a bulbous nose, sparse hair and epiphyseal coning. Autosomal dominant and recessive transmission are suggested. The presence of cone-shaped epiphyses, the major complaint of patients due to swelling over the phalangeal joints, requires differential diagnosis among various syndromes. This paper, describing a ten-year-old girl with TRPS I, aims to bring the features of the syndrome to medical attention.

Sotos syndrome with septo-optic dysplasia

A 12 2/12 year-old boy was admitted to our hospital with the complaint of rapid growth. His birth and postnatal growth history, developmental retardation, physical examination and skeletal radiograms suggested Sotos syndrome. CT and MRI findings revealed septo-optic dysplasia (SOD), which is usually characterized by poor growth, together with cerebral gigantism in our case. These two entities are both rare and as far as we know this is the first patient in the literature with Sotos syndrome and SOD.

Neutrophil chemotaxis and periodontal status in Down's syndrome patients

Along with clinical parameters, chemotaxis and random migration of neutrophils were evaluated in 15 patients with Down's syndrome (DS) and 15 healthy subjects. Signs of more severe gingival inflammation were present in the DS group. The random migration and chemotaxis of neutrophils were significantly decreased in comparison with the control group. In DS, the pathological status was attributed to these impaired host defense factors besides the existing bacterial plaque.