Autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations: a report of 8 cases and literature review / 中国当代儿科杂志

OBJECTIVES@#To summarize the clinical phenotype and genetic characteristics of children with autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations.@*METHODS@#A retrospective analysis was performed on the medical data of 8 children with autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations who were diagnosed and treated in the Department of Pediatrics, Xiangya Hospital of Central South University.@*RESULTS@#The mean age of onset was 9 months for the 8 children. All children had moderate-to-severe developmental delay (especially delayed language development), among whom 7 children also had seizures. Among these 8 children, 7 had novel heterozygous mutations (3 with frameshift mutations, 2 with nonsense mutations, and 2 with missense mutations) and 1 had 6p21.3 microdeletion. According to the literature review, there were 48 Chinese children with mental retardation caused by SYNGAP1 gene mutations (including the children in this study), among whom 40 had seizures, and the mean age of onset of seizures was 31.4 months. Frameshift mutations (15/48, 31%) and nonsense mutations (19/48, 40%) were relatively common in these children. In terms of treatment, among the 33 children with a history of epileptic medication, 28 (28/33, 85%) showed response to valproic acid antiepileptic treatment and 16 (16/33, 48%) achieved complete seizure control after valproic acid monotherapy or combined therapy.@*CONCLUSIONS@#Children with autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations tend to have an early age of onset, and most of them are accompanied by seizures. These children mainly have frameshift and nonsense mutations. Valproic acid is effective for the treatment of seizures in most children.

Clinical phenotypes and genetic features of epilepsy children with MBD5 gene variants / 中华儿科杂志

Objective: To summarize the phenotypes of epilepsy in patients with MBD5 gene variants. Methods: A total of 9 epileptic patients, who were treated in the Department of Pediatrics, Peking University First Hospital from July 2016 to September 2021 and detected with MBD5 gene pathogenic variants, were enrolled. The features of clinical manifestations, electroencephalogram (EEG), and neuroimaging were analyzed retrospectively. Results: Among 9 patients, 6 were male and 3 were female. Age at seizure onset ranged from 5 to 89 months. Multiple seizure types were observed, including generalized tonic clonic seizures (GTCS) in 7 patients, myoclonic seizures in 5 patients, focal seizures in 5 patients, atypical absence seizures in 3 patients, atonic seizures in 2 patients, myoclonus absence seizures in 1 patient, epileptic spasms in 1 patient, and tonic seizures in 1 patient. There were 8 patients with multiple seizure types, 2 patients with sensitivity to fever and 5 patients with clustering of seizures. Two patients had a history of status epilepticus. All patients had developmental delay before seizure onset. Nine patients had obvious language delay, and 6 patients had autism-like manifestations. Five patients had slow background activity in EEG. Interictal EEG showed abnormal discharges in 9 patients. Brain magnetic resonance imaging (MRI) was normal in all patients. A total of 9 epileptic patients carried MBD5 gene variants, all of them were de novo variants. There were MBD5 gene overall heterozygous deletion in 1 patient, large fragment deletions including MBD5 gene in 3 patients and single nucleotide variations (c.300C>A/p.C100X, c.1775delA/p.N592Tfs*29, c.1759C>T/p.Q587X, c.150_151del/p.Lys51Asnfs*6, c.113+1G>C) in 5 patients. The age at last follow-up ranged from 2 years and 9 months to 11 years and 11 months. At the last follow-up, 2 patients were seizure-free for more than 11 months to 4 years 6 months, 7 patients still had seizures. Conclusions: The initial seizure onset in patients with MBD5 gene variants usually occurs in infancy. Most patients have multiple seizure types. The seizures may be fever sensitive and clustered. Developmental delays, language impairments, and autistic behaviors are common. MBD5 gene variants include single nucleotide variations and fragment deletions. Epilepsy associated with MBD5 gene variants is usually refractory.

Analysis of clinical and genetic characteristics of epilepsy associated with chromosome 16p11.2 microdeletion / 中华儿科杂志

Objective: To investigate the clinical and genetic characteristics of epilepsy associated with chromosome 16p11.2 microdeletion. Methods: The patients (n=10) with 16p11.2 microdeletion found in children with epilepsy treated in Beijing Children's Hospital Affiliated to Capital Medical University from January 2018 to January 2021 were collected. The clinical manifestations, gene variations and prognosis were analyzed retrospectively. Results: A total of 10 children's data were collected, including 5 male and 5 female. The onset age of epilepsy was 4.5 (4.1,5.0) months. Regarding the seizure types, 7 cases had focal seizures with secondary generalization, 2 cases had generalized seizures, and 1 case had tonic seizures and spasms. Nine cases had cluster seizure attacks and 3 cases had status epilepticus. Seven cases had focal or multifocal epileptiform discharges in interictal electroencephalogram (EEG), 3 cases had borderline or normal EEG. Brain magnetic resonance imaging showed polymicrogyria in 1 case, paraventricular leukomalacia in 1 case, delayed myelination of white matter in 3 cases, and no obvious abnormalities in the other 5 cases. The patients were followed up for 0.5-3.5 years, with 1-3 kinds of antiepileptic drugs taken orally. The case with polymicrogyria still had seizures, however the other 9 cases had seizures controlled. The age of the last seizure attack was 8 (6, 12) months. There were 6 cases with mental and motor developmental delay before epilepsy onset. During the follow-up, 7 cases were retarded to varying degrees, while 3 cases had normal development. Regarding the genetic detection methods, 7 cases underwent whole exome sequencing, 2 cases underwent whole genome copy number variation detection, and 1 case underwent whole genome sequencing. The length of the 16p11.2 deletion in 10 cases ranged from 525 to 951 kb, and all contained the PRRT2 gene intact. Six cases were de novo variants, 1 case was inherited from the mother who had a history of convulsions in early childhood, and the source of variant was not verified in 3 cases, none of whose parents had relevant phenotype. Conclusions: The epilepsy associated with 16p11.2 microdeletion is mainly induced by the heterozygous deletion of PRRT2 gene in this region, however the phenotype is usually severe, and often combined with developmental and epileptic encephalopathy. Detection of copy number variation should be emphasized in children whose etiology is considered genetic but second-generation sequencing result is negative.

Clinical characteristics and gene analysis of GRIN2B gene related neurological developmental disorders in children / 中华儿科杂志

Objective: To analyse the clinical and gene characteristics of GRIN2B gene related neurological developmental disorders in children. Methods: The data of 11 children with GRIN2B gene related neurological developmental disorders from November 2016 to February 2021 were collected from Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health and analyzed retrospectively. The clinical features, electroencephalogram (EEG), brain imaging and gene testing results were summarized. Results: Among 11 children 6 were boys and 5 were girls. Two of them were diagnosed with developmental and epileptic encephalopathy. The ages of seizures onset were 3 months and 9 months, respectively. Seizure types included epileptic spasm, tonic seizures, tonic spasm and focal seizures, and 1 patient also had startle attacks. EEG showed interictal multifocal epileptiform discharges. Both of them were added with more than 2 anti-seizure drugs, which were partially effective but could not control. They had moderate to severe mental and motor retardation. The phenotype of 9 cases was developmental delay or intellectual disability without epilepsy, age of visit 1 year to 6 year and 4 months of whom 5 cases had severe developmental delay, 2 cases had moderate and 2 cases had mild delay. Multi-focal epileptiform discharges were observed in 3 cases, no abnormality was found in 3 cases, and the remaining 3 cases did not undergo EEG examination. Ten cases underwent brain magnetic resonance imaging (MRI), 6 cases had nonspecific abnormalities and 4 cases were normal. Nine GRIN2B gene heterozygous variants were detected by next-generation sequencing in these 11 patients, 8 cases had missense variants and 1 case had nonsense variant, all of which were de novo and 3 of which were novel. Missense variants were found in 10 patients, among them 6 cases had severe developmental delay, 3 cases had moderate and 1 case had mild developmental delay, but the patient with nonsense variant showed mild developmental delay without epilepsy. Conclusions: The phenotypes of GRIN2B gene related neurological developmental disorders in children are diverse, ranging from mild intellectual impairment without epilepsy to severe epileptic encephalopathy. Patients with epileptic phenotype usually have an onset age of infancy, and spasm and focal seizures are the most common seizure types. And the epiletice episodes are refractory. Most of the patients with missense variants had severe developmental delay.

NEXMIF mutations in intellectual disability and epilepsy: A report of 2 cases and literature review / 中南大学学报(医学版)

More than 100 genes located on the X chromosome have been found to be associated with X-linked intellectual disability (XLID) to date, and NEXMIF is a pathogenic gene for XLID. In addition to intellectual disability, patients with NEXMIF gene mutation can also have other neurological symptoms, such as epilepsy, abnormal behavior, and hypotonia, as well as abnormalities of other systems. Two children with intellectual disability and epilepsy caused by NEXMIF gene mutation were treated in the Department of Pediatrics, Xiangya Hospital, Central South University from March 8, 2017 to June 20, 2020. Patient 1, a 7 years and 8 months old girl, visited our department because of the delayed psychomotor development. Physical examination revealed strabismus (right eye), hyperactivity, and loss of concentration. Intelligence test showed a developmental quotient of 43.6. Electroencephalogram showed abnormal discharge, and cranial imaging appeared normal. Whole exome sequencing revealed a de novo heterozygous mutation, c.2189delC (p.S730Lfs*17) in the NEXMIF gene (NM_001008537). During the follow-up period, the patient developed epileptic seizures, mainly manifested as generalized and absent seizures. She took the medicine of levetiracetam and lamotrigine, and the seizures were under control. Patient 2, a 6-months old boy, visited our department due to developmental regression and seizures. He showed poor reactions to light and sound, and was not able to raise head without aid. Hypotonia was also noticed. The electroencephalogram showed intermittent hyperarrhythmia, and spasms were monitored. He was given topiramate and adrenocorticotrophic hormone (ACTH). Whole exome sequencing detected a de novo c.592C>T (Q198X) mutation in NEXMIF gene. During the follow-up period, the seizures were reduced with vigabatrin. He had no obvious progress in the psychomotor development, and presented strabismus. There were 91 cases reported abroad, 1 case reported in China, and 2 patients were included in this study. A total of 85 variants in NEXMIF gene were found, involving 83 variants reported in PubMed and HGMD, and the 2 new variants presented in our patients. The patients with variants in NEXMIF gene all had mild to severe intellectual disability. Behavioral abnormalities, epilepsy, hypotonia, and other neurological symptoms are frequently presented. The phenotype of male partially overlaps with that of female. Male patients often have more severe intellectual disability, impaired language, and autistic features, while female patients often have refractory epilepsy. Most of the variants reported so far were loss-of-function resulted in the reduced protein expression of NEXMIF. The degree of NEXMIF loss appears to correlate with the severity of the phenotype.

Clinical phenotype and genetic features of 16p11.2 microdeletion-related epilepsy in children / 中国当代儿科杂志

OBJECTIVES@#To study the clinical phenotype and genetic features of 16p11.2 microdeletion-related epilepsy in children.@*METHODS@#The medical data of 200 children with epilepsy who underwent a genetic analysis of epilepsy by the whole exon sequencing technology were collected retrospectively, of whom 9 children with epilepsy had 16p11.2 microdeletion. The clinical phenotype and genetic features of the 9 children with 16p11.2 microdeletion were analyzed.@*RESULTS@#The detection rate of 16p11.2 microdeletion was 4.5% (9/200). The 9 children with 16p11.2 microdeletion were 3-10 months old. They experienced focal motor seizures with consciousness disturbance, and some of the seizures developed into generalized tonic-clonic seizures. The interictal electroencephalogram showed focal or multifocal epileptiform discharge, and all 9 children responded well to antiepileptic drugs. The 9 children had a 16p11.2 deletion fragment size of 398-906 kb, and the number of deleted genes was 23-33 which were all pathogenic mutations. The mutation was of maternal origin in 2 children, of paternal origin in 1 child, and de novo in the other children.@*CONCLUSIONS@#16p11.2 microdeletion can be detected in some children with epilepsy. Most of the 16p11.2 microdeletion is de novo mutation and large gene fragment deletion. The onset of 16p11.2 microdeletion-related epilepsy in children is mostly within 1 year of life, and the epilepsy is drug-responsive.

De novo variant of CSNK2B causes Poirier-Bienvenu neurodevelopmental syndrome: two case report / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical characteristics and CSNK2B gene variant of 2 children with Poirier-Bienvenu neurodevelopmental syndrome, and to identify the possible pathogenic causes and provide evidence for clinical diagnosis.@*METHODS@#Two children with Poirier-Bienvenu neurodevelopmental syndrome were selected from West China Second University Hospital, Sichuan University. The clinical manifestations, laboratory examination and CSNK2B gene variant were analyzed.@*RESULTS@#The main manifestations of 2 children were epilepsy, motor or intellectual retardation. Whole exon sequencing showed that CSNK2B gene c. 291+4A>T heterozygous splicing variant was found in case one, and CSNK2B copy number variation(CNV) was lost in case two. Case one received no special treatment, followed up for 8+ months, seizures and motor development were improved; case two had recurrent seizures for 9+ years, and received levetiracetam and clonazepam antiepileptic treatment. No seizures have occurred for 2 years now, and a large number of epileptic discharges can still be seen in video electroencephalogram (VEEG) with slightly backward intelligence and language development.@*CONCLUSION@#Our study further proves that the pathogenic variant of CSNK2B is related to epilepsy with developmental disorder, and enrich is the CSNK2B gene variant spectrum. The pathogenesis of CSNK2B has great clinical heterogeneity, with great difference in severity of nervous system injury and different prognosis, and agenesis of corpus callosum may be one of its clinical phenotypes.

Analysis of three patients with KBG syndrome and epileptic seizures due to variants of ANKRD11 gene / 中华医学遗传学杂志

OBJECTIVE@#To summarize the clinical phenotype and genotypic characteristics of 3 patients with KBG syndrome and epileptic seizure.@*METHODS@#Clinical data of the patients were collected. Family-trio whole exon sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing.@*RESULTS@#Patients 1 and 2 were boys, and patient 3 was an adult woman. All patients had epileptic seizures and mental deficiency. Their facial features included triangular face, low hair line, hypertelorism, large forward leaning auricles, broad nasal bridge, upturned nostrils, long philtrum, arched upper lip, and macrodontia. The two boys also had bilateral Simian creases. WES revealed that the three patients all harbored heterozygous de novo frameshift variants in exon 9 of the ANKRD11 gene including c.2948delG (p.Ser983Metfs*335), c.5397_c.5398insC (p.Glu1800Argfs*150) and c.1180_c.1184delAATAA (p.Asn394Hisfs*42). So far 291 patients with ANKRD11 gene variants or 16q24.3 microdeletions were reported, with over 75% being de novo mutations.@*CONCLUSION@#Above findings have enriched the spectrum of ANKRD11 gene mutations underlying KBG syndrome. WES is helpful for the early diagnosis of KBG, and provided reference for genetic counseling of this disease.

Association of UGT1A6 gene polymorphism with clinical outcome in pediatric epileptic patients on sodium valproate monotherapy

Pediatric epilepsy comprises chronic neurological disorders characterized by recurrent seizures. Sodium valproate is one of the common antiseizure medications used for treatment. Glucuronide conjugation is the major metabolic pathway of sodium valproate, carried out by the enzyme uridine 5′-diphosphate (UDP) glucuronosyl transferase (UGT) whose gene polymorphisms may alter the clinical outcome. The objective of this study was to assess the association between UGT1A6 genetic polymorphism and clinical outcome in terms of efficacy and tolerability in pediatric epileptic patients on sodium valproate monotherapy. Pediatric epileptic patients (n=65) aged 2-18 years receiving sodium valproate monotherapy for the past one month were included. Genetic polymorphism patterns of UGT1A6 (T19G, A541G, A552C) were evaluated by PCR-RFLP. Clinical outcome was seizure control during the 6 months observation period. Tolerability was measured by estimating the hepatic, renal, and other lab parameters. Out of 65 patients, TT (40%), TG (57%), and GG (3%) patterns were observed in UGT1A6 (T19G) gene, AA (51%), AG (40%), and GG (9%) in (A541G) gene, and AA (43%), AC (43%), and CC (14%) in (A552C) gene. No statistical difference in clinical outcome was found for different UGT1A6 genetic polymorphism patterns. We concluded that different patterns of UGT1A6 genetic polymorphism were not associated with the clinical outcome of sodium valproate in terms of efficacy and tolerability. Sodium valproate was well-tolerated among pediatric patients with epilepsy and can be used as an effective antiseizure medication.

Penetrance estimation of PRRT2 variants in paroxysmal kinesigenic dyskinesia and infantile convulsions / 医学前沿

Proline-rich transmembrane protein 2 (PRRT2) is the leading cause of paroxysmal kinesigenic dyskinesia (PKD), benign familial infantile epilepsy (BFIE), and infantile convulsions with choreoathetosis (ICCA). Reduced penetrance of PRRT2 has been observed in previous studies, whereas the exact penetrance has not been evaluated well. The objective of this study was to estimate the penetrance of PRRT2 and determine its influencing factors. We screened 222 PKD index patients and their available relatives, identified 39 families with pathogenic or likely pathogenic (P/LP) PRRT2 variants via Sanger sequencing, and obtained 184 PKD/BFIE/ICCA families with P/LP PRRT2 variants from the literature. Penetrance was estimated as the proportion of affected variant carriers. PRRT2 penetrance estimate was 77.6% (95% confidence interval (CI) 74.5%-80.7%) in relatives and 74.5% (95% CI 70.2%-78.8%) in obligate carriers. In addition, we first observed that penetrance was higher in truncated than in non-truncated variants (75.8% versus 50.0%, P = 0.01), higher in Asian than in Caucasian carriers (81.5% versus 68.5%, P = 0.004), and exhibited no difference in gender or parental transmission. Our results are meaningful for genetic counseling, implying that approximately three-quarters of PRRT2 variant carriers will develop PRRT2-related disorders, with patients from Asia or carrying truncated variants at a higher risk.

A case of 16p13.11 microdeletion syndrome with febrile convulsion as the main manifestation / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a girl with febrile convulsion as the main manifestation.@*METHODS@#The child was subjected to whole exome sequencing (WES) and copy number variation sequencing(CNV-seq). Fluorescence quantitative PCR was carried out to validate the microdeletion in her family.@*RESULTS@#The 7-year-old girl was diagnosed with febrile convulsion (complex type) for having fever for 3 days, mild cough and low thermal convulsion once. Her father, mother and aunt also had a history of febrile convulsion. A heterozygous deletion with a size of approximately 1.5 Mb was detected in the 16p13.11 region by WES and CNV-seq. The deletion has derived from her father and was confirmed by fluorescence quantitative PCR.@*CONCLUSION@#16p13.11 microdeletion syndrome has significant clinical heterogeneity. Different from those with epilepsy, mental retardation, autism, multiple malformations, carriers of 16p13.11 deletion may only manifest with febrile convulsion. Deletion of certain gene(s) from the region may be related to febrile convulsion and underlay the symptom of this child.

Genetic and phenotypic analysis of a patient with phosphogylcerate dehydrogenase deficiency / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with ocular anomaly, microcephaly, growth retardation and intrauterine growth restriction.@*METHODS@#The patient underwent ophthalmologic examinations including anterior segment photography, fundus color photography, and fundus fluorescein angiography. The patient and her parents were subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing and bioinformatic analysis.@*RESULTS@#The patient was found to have bilateral persistent pupillary membrane and coloboma of inferior iris, in addition with macular dysplasia and radial pigmentation near the hemal arch of the temporal retina. She was found to have carried compound heterozygous missense variants of the PHGDH gene, namely c.196G>A and c.1177G>A, which were respectively inherited from her father and mother. Bioinformatic analysis suggested both variants to be pathogenic.@*CONCLUSION@#The patient was diagnosed with phosphoglycerate dehydrogenase deficiency. Above finding has enriched the phenotypic spectrum of the disease with ocular manifestations.

Estudio clínico genético en pacientes con complejo de esclerosis tuberosa / Clinical and genetic study patients with tuberous sclerosis complex

El complejo de esclerosis tuberosa (CET) es una enfermedad autosómica dominante multisistémica producida por mutaciones en los genes supresores de tumores TSC1 o TSC2. Objetivo: Caracterizar clínica y genéticamente pacientes pediátricos con diagnóstico de CET. Pacientes y Método: Estudio descriptivo de registros clínicos de 42 pacientes pediátricos controlados en un servicio de neuropsiquiatría infantil con diagnóstico de CET y estudio genético en 21 de ellos. Se amplificó por reacción en cadena de la polimerasa y secuenció el exón 15 del gen TSC1 y los exones 33, 36 y 37 del gen TSC2. Se analizó la relación entre las mutaciones encontradas con la severidad y evolución clínica. Resultados: En el 61,9% de los pacientes las manifestaciones comenzaron antes de los 6 meses de edad. Las manifestaciones iniciales de CET más frecuentes fueron las crisis convulsivas (73,8%) y el hallazgo de rabdomiomas cardiacos (16,6%). Durante su evolución, todos los pacientes presentaron compromiso neurológico; el 92,9% presentó epilepsia. Todos los pacientes presentaron máculas hipomelanóticas, 47,6% pangiofibromas faciales, 23,8% parches de Shagreen, 47,6% rabdomiomas cardiacos y 35,7% hamartomas retinianos. El estudio genético realizado a 21 pacientes identificó 2 mutaciones heterocigotas patogénicas en TSC1 y una en TSC2. Este último paciente presentaba un fenotipo clínico más severo. Conclusiones: Las manifestaciones neurológicas y dermatológicas fueron las más frecuentes en los pacientes con CET. Se identificaron 2 mutaciones patogénicas en el gen TSC1 y una en el gen TSC2. La mutación en TSC2 se manifestó en un fenotipo clínico más severo.

Tuberous sclerosis complex (TSC) is a multisystem autosomal dominant disease caused by mutations in the tumor suppressor genes TSC1 or TSC2. Objective: To characterize clinically and genetically patients diagnosed with TSC. Patients and Method: Descriptive study of clinical records of 42 patients from a pediatric neuropsychiatry department diagnosed with TSC and genetic study in 21 of them. The exon 15 of TSC1 gene and exons 33, 36 and 37 of TSC2 gene were amplified by polymerase chain reaction and sequenced. The relationship between the mutations found with the severity and clinical course were analyzed. Results: In 61.9% of the patients the symptoms began before 6 months of age. The initial most frequent manifestations of TSC were new onset of seizures (73.8%) and the detection of cardiac rhabdomyomas (16.6%). During the evolution of the disease all patients had neurological involvement; 92.9% had epilepsy. All patients presented hypomelanotic spots, 47.6% facial angiofibromas, 23.8% Shagreen patch, 47.6 heart rhabdomyomas and 35.7% retinal hamartomas. In the genetic study of 21 patients two heterozygous pathogenic mutations in TSC1 and one in TSC2 genes were identified. The latter had a more severe clinical phenotype. Conclusions: Neurological and dermatological manifestations were the most frequent ones in patients with TSC. Two pathogenic mutations in TSC1 and one in TSC2 genes were identified. The patient with TSC2 mutation manifested a more severe clinical phenotype.

Hypoparathyroidism-retardation-dysmorphism syndrome.

Congenital hypoparathyroidism, growth retardation and facial dysmorphism is a rare autosomal recessive disorder seen among children born to consanguineous couple of Arab ethnicity. This syndrome is commonly known as Sanjad- Sakati or hypoparathyroidism‑retardation‑dysmorphism syndrome (HRD). We report 13‑year‑old Hindu boy with hypoparathyroidism, tetany, facial dysmorphism and developmental delay, compatible with HRD syndrome.

Long QT Syndrome: a Korean Single Center Study

The long QT syndrome (LQTS) is a rare hereditary disorder in which affected individuals have a possibility of ventricular tachyarrhythmia and sudden cardiac death. We investigated 62 LQTS (QTc > or = 0.47 sec) and 19 family members whose genetic study revealed mutation of LQT gene. In the proband group, the modes of presentation were ECG abnormality (38.7%), aborted cardiac arrest (24.2%), and syncope or seizure (19.4%). Median age of initial symptom development was 10.5 yr. Genetic studies were performed in 61; and mutations were found in 40 cases (KCNQ1 in 19, KCNH2 in 10, SCN5A in 7, KCNJ2 in 3, and CACNA1C in 1). In the family group, the penetrance of LQT gene mutation was 57.9%. QTc was longer as patients had the history of syncope (P = 0.001), ventricular tachycardia (P = 0.017) and aborted arrest (P = 0.010). QTc longer than 0.508 sec could be a cut-off value for major cardiac events (sensitivity 0.806, specificity 0.600). Beta-blocker was frequently applied for treatment and had significant effects on reducing QTc (P = 0.007). Implantable cardioverter defibrillators were applied in 6 patients. Congenital LQTS is a potentially lethal disease. It shows various genetic mutations with low penetrance in Korean patients.

A clinical follow-up of 35 Brazilian patients with Prader-Willi Syndrome

OBJECTIVE: Prader-Willi Syndrome is a common etiology of syndromic obesity that is typically caused by either a paternal microdeletion of a region in chromosome 15 (microdeletions) or a maternal uniparental disomy of this chromosome. The purpose of this study was to describe the most significant clinical features of 35 Brazilian patients with molecularly confirmed Prader-Willi syndrome and to determine the effects of growth hormone treatment on clinical outcomes. METHODS: A retrospective study was performed based on the medical records of a cohort of 35 patients diagnosed with Prader-Willi syndrome. The main clinical characteristics were compared between the group of patients presenting with microdeletions and the group presenting with maternal uniparental disomy of chromosome 15. Curves for height/length, weight and body mass index were constructed and compared between Prader-Willi syndrome patients treated with and without growth hormone to determine how growth hormone treatment affected body composition. The curves for these patient groups were also compared with curves for the normal population. RESULTS: No significant differences were identified between patients with microdeletions and patients with maternal uniparental disomy for any of the clinical parameters measured. Growth hormone treatment considerably improved the control of weight gain and body mass index for female patients but had no effect on either parameter in male patients. Growth hormone treatment did not affect height/length in either gender. CONCLUSION: The prevalence rates of several clinical features in this study are in agreement with the rates reported in the literature. Additionally, we found modest benefits of growth hormone treatment but failed to demonstrate differences between patients with microdeletions and those with maternal uniparental disomy. The control of weight gain in patients with Prader-Willi syndrome is complex and does not depend exclusively on growth hormone treatment.

Convulsiones familiares benignas de la infancia / Bening infantile familial convulsions

Introducción: Las convulsiones familiares benignas de la infancia (CFBI) se caracterizan por crisis parciales breves, en algunas ocasiones secundariamente generalizadas, que se inician durante el primer año de vida y presentan historia familiar de convulsiones con características electroclínicas y edad de comienzo similares. El objetivo fue determinar las características clínico electroencefalográficas en lactantes con examen neurológico normal, con convulsiones parciales y generalizadoras con antecedentes conocidos en padre y madre de crisis convulsivas de iguales características clínicas y edad de comienzo para ratificar la existencia de las CFBI. Material y métodos: Se incluyeron pacientes con examen neurológico normal que comenzaron entre los 2 meses y los 2 años de vida con convulsiones parciales simples, parciales complejas y generalizadas, ausencia de factores etiológicos, estudios neurorradiológicos normales y con antecedentes en padre o madre de crisis epilépticas de similares características y edad de comienzo. Se excluyeron pacientes con lesión cerebral y antecedentes personales de significación patológica. Dieciséis pacientes (10 mujeres y 6 varones) fueron evaluados en el servicio de neurología del Hospital "Garrahan" en el período comprendido entre febrero de 1990 y junio de 1996. Analizamos el sexo, la edad de comienzo de las convulsiones, historia familiar de epilespsia, examen neurológico, semiología, distribución, frecuencia y duración de las crisis, EEG y estudios neurorradiológicos. Resultados: La edad de comienzo de las crisis epilépticas fue entre los 3 y 22 meses de edad con una mediana de 5 meses. Las convulsiones generalizadas como único tipo de crisis se presentaron en 7 pacientes (43,8 por ciento). En 3 (18,7 por ciento) las crisis fueron solamente parciales. Seis pacientes tuvieron concomitantemente crisis parciales y generalizadas (37,5 por ciento). Las crisis fueron breves en todos los casos (100 por ciento), se presentaron agrupadas en 8 pacientes (50 por ciento) y ocurrieron en vigilia en los 16 casos (100 por ciento). El EEG interictal fue normal en 15 pacientes (93,7 por ciento). En un caso se encontró un foco de espigas en la región occipital derecha. Existieron antecedentes familiares en otros miembros que no fueran padre o madre en 11 pacientes (68,7 por ciento). Conclusiones: En la muestra estudiada las convulsiones se presentaron agrupadas en el 50 por ciento de los casos,...

Genética de la epilepsia

La evidencia de un factor genético en la epilepsia se ha obtenido de varias fuentes: La presencia de modelos electroencefalográficos familiares no específicos, de crisis convulsivas en muchas especies, y de enfermedades hereditarias en donde la epilepsia es un síntoma. En pacientes con convulsiones tónico-clónicas generalizadas, crisis de ausencia, epilepsia por fotosensibilidad y convulsiones febriles, el porcentaje de epilepsia en sus parientes es mas alto que en los parientes de pacientes con crisis parciales. También es notorio la diferencia en el riesgo para un hijo de desarrollar epilepsia, dependiendo de si es el padre o la madre el que padece la enfermedad. Los datos electroencefalográficos han sido el soporte de la teoría de que factores genéticos juegan un papel importante en la epilepsia, pero el EEG por si solo no puede definir un riesgo específico de desarrollar epilepsia en descendientes de individuos con dicha entidad