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ABSTRACT: Angelman syndrome (AS) is a neurobehavioral disorder caused by lack of function of the maternal copy of the ubiquitin-protein ligase E3A (UBE3A) gene. In our study, 49 unrelated patients with classic AS phenotypes were confirmed by methylation-specific PCR (MS-PCR) analysis, short tandem repeat linkage analysis, and mutation screening of the UBE3A gene. Among the Chinese AS patients, 83.7% (41/49) had deletions on maternal chromosome 15q11.2-13. Paternal uniparental disomy, imprinting defects, and UBE3A gene mutations each accounted for 4.1% (2/49). Two AS patients were confirmed by MS-PCR analysis, but the pathogenic mechanism was unknown because their parents' samples were unavailable. Of the 2 described UBE3A gene mutations, i.e., p.Pro400His (c.1199C>A) and p.Asp563Gly (c.1688A>G), the latter has not been reported previously. Mutation transmission analysis showed that the p.Pro400His and p.Asp563Gly mutations originated from asymptomatic mothers. The patients with the maternal deletion showed AS clinical manifestations that were consistent with other studies. However, the incidence of microcephaly (36.7%, 11/30) was lower than that in the Caucasian population (approximately 80%), but similar to that of the Japanese population (34.5%). Our study demonstrated that the occurrence of microcephaly in AS may vary among different populations.
Clinical Genetics 04/2013; · 3.13 Impact Factor
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ABSTRACT: Angelman syndrome (AS) is a neurogenetic disorder caused by an expression defect of the maternally inherited copy of ubiquitin protein ligase E3A (UBE3A) gene from chromosome 15. Although the most common genetic defects include maternal deletions of chromosome 15q11-13, paternal uniparental disomy and imprinting defect, mutations in the UBE3A gene have been identified in approximately 10% of AS patients.
A Chinese girl of 28 months presented clinical manifestation of AS. Genetic diagnosis and molecular genetic defects were studied by methylation-specific PCR (MS-PCR) and linkage analysis by short tandem repeat (STR). We further performed sequence analysis of all the coding exons and flanking sequences of the UBE3A gene. The novel mutation screening was also performed in 100 unrelated healthy individuals to exclude the possibility of identifying a polymorphism variation.
The MS-PCR analysis of the patient showed biparental inheritance of chromosome 15 with a normal methylation pattern in the 15q11-q13 region. And STR analysis revealed that the patient also inherited biparental alleles for six microsatellites. A novel mutation, cDNA1199 C> A (p.P400H), in exon 9 of the maternal UBE3A gene, was identified in the patient. Meanwhile, the mutation was observed in the patient's mother who had a normal phenotype.
It is necessary to perform the UBE3A gene mutation analysis in non-deletion/non-UPD/non-ID patients with AS. The clinical picture of the patient is concordant with that observed in previously reported AS patients with UBE3A mutation.
Chinese medical journal 01/2011; 124(1):84-8. · 0.86 Impact Factor
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ABSTRACT: Angelman syndrome (AS) is a neurodevelopmental genetic disorder that maps to 15q11-13. The primary phenotypes are attributable to loss of expression of imprinted UBE3A gene within this region which can arise by means of a number of mechanisms. The purpose of this study was to make a genetic diagnosis and to analyze the clinical features in suspected patients with AS.
A total of 17 cases were diagnosed clinically as AS including 7 males and 10 females. The age at the time of diagnosis ranged from 8 months to 5 years. Genetic diagnosis was made by methylation-specific PCR (MS-PCR), linkage analysis by short tandem repeat (STR) and chromosome karyotype analysis. According to the international diagnostic criteria of AS, the related characteristic clinical features of the AS patients with deletion of 15q11-13 were analyzed and summarized.
Deletion of 15q11-13 was confirmed by genetic diagnosis in 17 AS patients. No abnormal findings were observed when they were born. Developmental delay in movement, speech impairments and happy disposition were observed in 100% (17/17) AS patients. And the severe speech deficit was much easier and more obvious to observe than movement. About 80% (14/17) - 90% (15/17) AS patients presented frequent clinical characteristics, such as seizures and abnormal EEG. However, microcephaly could only be observed in 35% (6/17) AS patients. Regarding the associated findings of AS, 41% (7/17) - 77% (13/17) AS patients could be observed with flat occiput/occipital groove, prognathia, wide mouth, wide-spaced teeth, frequent drooling, excessive mouth behaviors, hypopigmented skin, light hair compared to parents, flexed arm position during ambulation and sleep disorder etc. These features occurred at a higher frequency in those patients of > 2 years old group than that of < 2 years old group.
The testing strategies of MS-PCR and STR linkage analysis combined with chromosome karyotype analysis were appropriate to the molecular genetic diagnosis of AS. In our analysis of clinical features, there was a lower rate of small head circumference (HC) in 35% patients compared with 80% patients in Caucasian with microcephaly, which might be attributable to the phenotypic heterogeneity in different races. And the birth history, movement and speech development and main clinical features of the Chinese AS patients were consistent with those of other studies. Clinical analysis in patients of different age groups showed that findings associated with AS would be more easily observed with the age increasing. Genetic diagnosis should be performed in clinically suspected AS patients.
Zhonghua er ke za zhi. Chinese journal of pediatrics 12/2010; 48(12):939-43.
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ABSTRACT: To investigate the clinical manifestations and EEG characteristics of Angelman syndrome in children, and to strengthen the recognition of this disease.
Fourteen children with Angelman syndrome received video EEG monitoring, head MRI/CT and gene test, 11 patients received the metabolic investigations (e.g., lactic acid, ammonia, GC/MS and MS/MS). Eight patients received Gesell test. The patients were followed up for 1-3 years.
Of the 14 cases, 4 were male and 10 female, their age was from 8 months to 3 years and 7 months. The clinical characteristics included prominent lower jaw and wide mouth, fair skin and yellow hair, light-colored iris, paroxysmal laughter, astasia and language backward. Twelve patients had epileptic seizures; 10 patients displayed non-convulsive status epilepticus (NCSE), 9 patients displayed myoclonic, atypical absence, and non-convulsive seizure simultaneously; myoclonic, generalized tonic-clonic seizure and complex partial seizure in 1 each; 4 patients had fever in early seizures. The EEG showed paroxysmal middle-high amplitude 2-3 Hz spike and spinous slow-wave in 8 patients. Four patients showed paroxysmal frequently middle-high amplitude 2-3 Hz slow waves mixed with sharps. The other 2 patients showed a normal EEG. All the patients were diagnosed with genetics testing. The results included maternal deletion of chromosome 15q11-13 in 12, paternal uniparental disomy in 1 and imprinting defects in 1.
There are characteristic clinical manifestation and craniofacial features in Angelman syndrome patients. Some patients have specific EEG patterns. Abnormal region of chromosome 15q11-13 is the basis of diagnosis.
Zhonghua er ke za zhi. Chinese journal of pediatrics 10/2010; 48(10):783-6.
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ABSTRACT: To study the clinical and laboratory features of the patients with Menkes disease.
Three infants were diagnosed as Menkes disease. Their clinical feature, laboratory findings, radiological manifestation and genes were reviewed.
All the three cases were male infants. Their clinical manifestations began at the 3, 5 and 6 months after birth. They all had light complexion, sparse fuzzy woolly hair. The main clinical manifestation was severe mental retardation. The first and the third case also had focal clonus seizures. The second case had feeding difficulty after birth. Their hair showed pili torti and trichorrhexis nodosa microscopically. Their ceruloplasmin in plasma were 32.3 mg/L, 72.5 mg/L and 60.7 mg/L, which were significantly lower as compared with the normal values. Their neuroimaging findings were cortical atrophy, delayed myelination of the white matter and tortuosity of the intracranial vessels. The gene examination of the first and the second case showed deletion and nonsense mutation on exon 14 respectively.
Menkes disease is an X-linked recessive disorder characterized by a copper-transporting ATPase defect. The main clinical manifestation is progressive nerve damage. Patients with the disease have special face and hair abnormality, and have morphological changes of brain blood vessels and cerebral atrophy.
Zhonghua er ke za zhi. Chinese journal of pediatrics 08/2009; 47(8):604-7.
