[Show abstract][Hide abstract] ABSTRACT: Genetic markers associated with disease are often non-functional and generally tag one or more functional "causative" variants in linkage disequilibrium. Markers may not show tight linkage to the causative variants across multiple ethnicities due to evolutionary divergence, and therefore may not be informative across different population groups. Validated markers of disease suggest causative variants exist in the gene and, if the causative variants can be identified, it is reasonable to hypothesize that such variants will be informative across diverse populations. The aim of this study was to test that hypothesis using functional Interleukin-1 (IL-1) gene variations across multiple ethnic populations to replace the non-functional markers originally associated with chronic adult periodontitis in Caucasians.
Adult chronic periodontitis cases and controls from four ethnic groups (Caucasians, African Americans, Hispanics and Asians) were recruited in the USA, Chile and China. Genotypes of IL1B gene single nucleotide polymorphisms (SNPs), including three functional SNPs (rs16944, rs1143623, rs4848306) in the promoter and one intronic SNP (rs1143633), were determined using a single base extension method or TaqMan 5' nuclease assay. Logistic regression and other statistical analyses were used to examine the association between moderate to severe periodontitis and IL1B gene variations, including SNPs, haplotypes and composite genotypes. Genotype patterns associated with disease in the discovery study were then evaluated in independent validation studies.
Significant associations were identified in the discovery study, consisting of Caucasians and African Americans, between moderate to severe adult chronic periodontitis and functional variations in the IL1B gene, including a pattern of four IL1B SNPs (OR = 1.87, p < 0.0001). The association between the disease and this IL1B composite genotype pattern was validated in two additional studies consisting of Hispanics (OR = 1.95, p = 0.04) or Asians (OR = 3.27, p = 0.01). A meta-analysis of the three populations supported the association between the IL-1 genotype pattern and moderate to severe periodontitis (OR 1.95; p < 0.001). Our analysis also demonstrated that IL1B gene variations had added value to conventional risk factors in predicting chronic periodontitis.
This study validated the influence of IL-1 genetic factors on the severity of chronic periodontitis in four different ethnicities.
Journal of Periodontal Research 04/2014; 50(1). DOI:10.1111/jre.12181 · 2.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We performed Killer cell immunoglobulin-like receptor (KIR) genotyping on 1271 individuals of Chinese Han origin including 102 families and 965 unrelated individuals. The families (with one child and both parents) were subjected for haplotype analysis. Forty-one different genotypes were identified. The frequencies of the KIR genotypes found in the family panel were confirmed by those found in the unrelated panel. The family study showed segregation of one A haplotype and at least 15 unique B haplotypes. The most commonly observed haplotypes in group B were B1, B2, and B3, present at a frequency of 10.05%, 6.62%, and 4.90%, respectively. On the basis of the combination of KIR genes, six centromeric and seven telomeric gene motifs have been identified. Motif cB02 was the most frequent haplotype B specific centromeric segment while tB01 was the most frequent haplotype B specific telomeric segment. The distinct distribution of KIR haplotypes in each population may reflect the history of directional and balancing selection of different races. The gene combinations of group A and B1/B2/B3 haplotype were the most frequent genotypes named as Bx1, Bx2, and Bx3, present at a frequency of 13.72%, 7.35%, and 4.41% in the family panel, and at a frequency of 15.86%, 10.15%, and 5.80% in the unrelated panel, respectively. Overall, this study showed the diversity of KIR haplotypes and genotypes in Chinese Han population and developed a criterion for distinguish KIR haplotypes/genotypes for the population. KIR genotyping and haplotype analysis should be useful for selection of the most optimum donor grafts with favorable KIR gene content for transplants.
[Show abstract][Hide abstract] ABSTRACT: To analyze the clinical and SLC2A1 gene mutation characteristics of glucose transporter type 1 deficiency syndrome.
The detailed clinical manifestations of six cases were recorded. The laboratory tests including EEG, MRI, blood chemistry, and lumbar puncture were performed. SLC2A1 gene mutations were analyzed by PCR, DNA sequencing and multiplex ligation-dependent probe amplification (MLPA).
Patient 1, 2 and 3 had classical clinical symptoms including infantile onset seizures, development delay. Patient 4, 5 and 6 had non-classical clinical symptoms including paroxysmal behavior disturbance, weakness, ataxia, lethargy, especially after fasting or exercise, without severe seizures. The plasma glucose levels were normal. The CSF glucose levels decreased in all the six cases, ranged from 1.10 mmol/L to 2.45 mmol/L, the mean level was 1.68 mmol/L. The CSF glucose/plasma glucose ratios decreased, ranged from 0.16 to 0.51, the mean ratio was 0.34. Four patients had normal EEG. Two patients had focal and diffuse epileptiform discharge, and one of them also had paroxysmal occipital or generalized high-amplitude slow waves during awake and sleep time. MRI abnormalities were found in three patients, patient 1 with mild brain atrophy, patient 3 with bilateral ventricle plump, and patient 4 with high signals in T2 in the frontal and occipital white matter, interpreted as hypomyelination. SLC2A1 gene mutations were found in six cases. Patient 1 has large scale deletion in exon 2. In patient 2 to 6, the mutations were c.741 G>A (E247K), 599delA, 761delA, c.1148 C>A (P383H), c.1198 C>T (R400C) respectively. Two patients were treated with ketogenic diet. The seizures disappeared and development became normal. Three patients responded to frequent meals with snacks. One patient refused any treatments, the symptoms continued to exist.
The clinical manifestations of glucose transporter type 1 deficiency syndrome are varied. The common symptoms included infantile onset seizures and various paroxysmal events. These neurologic symptoms generally fluctuated and were influenced by factors such as fasting or fatigue. This feature could be a very important clue for the diagnosis of GLUT1-DS. Lumbar puncture is recommended in patients with episodic CNS symptoms especially after fasting. GLUT1-DS is a treatable neurometabolic disorder, early diagnosis and treatment may improve the prognosis of the patients.
Zhonghua er ke za zhi. Chinese journal of pediatrics 06/2013; 51(6):443-447.
[Show abstract][Hide abstract] ABSTRACT: To delineate the characteristics of the clinical manifestation, pathology of skeletal muscle and gene mutations of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episode (MELAS) in children.
The clinical manifestation, laboratorial data, brain images, muscle pathology and mitochondrial gene mutations were analyzed in 24 patients with MELAS who were diagnosed in Department of Pediatrics, Peking University First Hospital. Their prognosis was evaluated by following up.
Symptoms of central nervous system such as stroke-like episodes, vomiting, convulsion and headache were present in all the 24 cases. Nine cases had the symptoms of myopathy. Twenty cases had developmental delay. Short stature, being thin and hairy was very common in these cases. Serum lactate level increased in all the cases, pyruvate increased in 17 cases. Elevated CSF lactate was found in 2 cases. Magnetic resonance imaging (MRI) was performed on 24 cases, out of them 23 were abnormal. The lesions mainly involved cerebral lobes. Occipital lobe was the most common site of lesions. Computed tomography (CT) was performed on 13 cases, low density lesions were present in 10 cases, basal ganglia calcifications in 5 cases. Muscle biopsy was performed on 8 cases, ragged-red fibers (RRF) were found in 4/8 cases, and abnormal accumulation of mitochondria were found in 3/8 cases. The mtDNA gene mutational analysis showed A3243G mutation in these patients. The mutation rates varied from 11.6% to 75.0%. The same mutation were found in 4/5 mothers who had the genetic tests, and the mutation rates of the mothers varied from 15.0% to 23.6%. The clinical information of 11 cases was available through recent following up. Three cases died, the others had some degrees of mental retardation.
Children with MELAS had various clinical manifestations. Central nervous system and skeletal muscle were usually involved. Short stature and hypertrichosis were common signs. The prognosis of this disease was disappointing. mtDNA A3243G was the most common mutation in MELAS. Fully understanding the characteristics of its clinical manifestation, laboratory tests, brain image, muscle pathology and molecular features can be helpful to the early diagnosis and treatment.
Zhonghua er ke za zhi. Chinese journal of pediatrics 02/2013; 51(2):130-5.
[Show abstract][Hide abstract] ABSTRACT: Children with refractory epilepsy who suffered from severe liver function impairment during valproic acid (VPA) treatment at routine dosage were studied. The clinical manifestations and therapeutic approaches were investigated in order to improve its diagnosis and management.
Clinical information as well as features and management of 4 inpatients who were suffered from intractable epilepsy with severe liver function impairment induced by VPA since 2006 were collected and analyzed, including age of onset of epilepsy, VPA using age and the time when liver injury occurred, clinical manifestations, auxiliary examinations and management.
Among the 4 cases, three were male and one was female. The admitted age ranged from 1 - 9 years and 1 month. The course of disease was 25 d - 6 months. They manifested as refractory epilepsy of epilepsia partialis continua which was difficult to control. After using VPA for 62 d (50 - 76 d), all developed severe impairment of liver synthetic function which was not related to the concentration of VPA. One was diagnosed with Alpers syndrome, two were suspicious of Alpers syndrome, and the other was diagnosed gliocytoma after brain biopsy. VPA was stopped immediately and symptomatic therapies were used. Other than that, intravenous injection of L-carnitine in 3 cases recovered the liver function.
VPA-associated severe hepatotoxicity can manifest first as impaired liver synthetic function. Besides alanin transaminase and aspartate transaminase, the liver synthetic function test is more important than monitoring of liver enzymatic functions in monitoring for the hepatotoxicity. Intravenous injection of L-carnitine in early stage showed good treatment effect.
Zhonghua er ke za zhi. Chinese journal of pediatrics 12/2012; 50(12):890-4.
[Show abstract][Hide abstract] ABSTRACT: Purpose: Rett syndrome is one of several genetic disorders known to cause severe intellectual and physical disability, mostly in girls. Girls affected by Rett syndrome appear to develop normally in the first 6 months of life, after which the usual clinical presentation comprises regression of communication and hand skills, the appearance of hand stereotypies and impaired gait. Intellectual disability affects more than 1.5% of the population of children in developing countries yet we know little about the daily lives and support services available for them and their caregivers. Method: This qualitative study explored the daily experiences of 14 mothers and one grandmother caring for a child with Rett syndrome in China via telephone interviews. Results: Participants reported a lack of education, rehabilitation and support services available to them. Limited access to information reduced families' capacity to adequately meet the needs of their child. These gaps were further exacerbated by discrimination and perceived stigma from some members of the community. Conclusions: Additional support services and educational programs at the governmental level can improve the quality of life of persons with an intellectual disability and their families and programs involving community participation in the care of people with disabilities may help to address discrimination. [Box: see text].
Disability and Rehabilitation 09/2012; 35(4). DOI:10.3109/09638288.2012.715720 · 1.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: To perform a follow-up of 25 Chinese children with gene-confirmed PLA2G6-associated neurodegeneration (PLAN). METHODS: We recruited patients with infantile neuroaxonal dystrophy (INAD) according to the criteria proposed by Nardocci et al. Follow-up was conducted 7 months-8 years after the first visit. PLA2G6 gene was sequenced, and copy number variation (CNV) was detected in patients with only one mutant allele and in mutation-negative patients. Published patients with late-onset PLAN until 2012 were reviewed. RESULTS: All patients with INAD exhibited rapid decline in motor and mental function, consistent with previous reports from other populations. Epileptic seizures occurred in 16.7%. One teenager with late-onset PLAN was diagnosed and followed up. The age of disease onset in published late-onset PLAN ranged between 18 months and 37 years. Initial presentations included gait instability (79.0%), mood/behavior changes (10.5%), dysarthria (5.26%) and cognitive deterioration (5.3%). Compared with INAD, cerebellar atrophy (42.1%) was less frequent in the late-onset cases, with cerebral atrophy more common (71.4%). Brain iron accumulation was seen in 52.6%. PLA2G6 mutations were identified by DNA sequencing in 92.3% of clinically diagnosed INAD cases and in the late-onset case. Twenty-seven different mutations were found, of which 13 were novel. No CNVs were detected. Maternal uniparental disomy was confirmed in one INAD case. CONCLUSIONS: This is the largest report on PLAN in Chinese population. We suggest PLA2G6 should be screened in any patient exhibiting progressive gait disturbance, bradykinesia, dysarthria, tremors, mood/behavior changes or cognitive decline, especially when associated with cerebellar atrophy and/or iron accumulation and/or cerebral atrophy.
European Journal of Neurology 08/2012; 20(2). DOI:10.1111/j.1468-1331.2012.03856.x · 4.06 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Niemann-Pick disease type C (NP-C), caused by mutations of either NPC1 or NPC2 gene, is an inherited lysosomal lipid storage disorder that is difficult to be diagnosed and treated. NP-C is rarely reported in China and so far very few literatures are available for Chinese clinical workers. To better characterize this disease in China and improve genetic counseling, mutational analyses of NPC1 gene were carried out in 6 unrelated Chinese patients.
Clinical data of the probands from 2007 to 2010 were collected and analyzed. All exons of NPC1 were analyzed by direct sequencing.
The six cases, four males and two females, included three cases of late infantile subtype and three cases of juvenile subtype. Case one and case six had siblings who suffered from the same disease. The onset of clinical symptoms varied from three to ten years old, and they included progressive cognitive and language impairment, and motion retrogradation. All were caught by focal or generalized seizures from one to four years after the onset. Vertical supranuclear gaze palsy, dysarthria, dysphagia, internal rotation and adduction of bilateral hands and splenomegaly occurred gradually during the disease progression. Five patients had laughter-cataplexy. MRI indicated mild brain atrophy. Sea blue cells and Niemann-Pick cells were presented in bone marrow smears. Activity of acid sphingomyelinase was normal or only slightly lower than controls. Supporting and symptomatic treatments could improve some of the clinical signs. We identified 10 different NPC1 mutations were identified in 12/12 alleles, 3 of which are described for the first time. All mutations were missense mutations, which located throughout the gene with five clustering in the cysteine-rich luminal domain. Homozygous mutation of S865L correlated with a relatively severe juvenile neurological form.
NP-C is a rare autosomal recessive lysosomal storage disease that affects intellectual development of children, causing dementia, vegetative state and eventual death. The awareness of NP-C should be raised in the Chinese population. The typical clinical features of this disease include vertical supranuclear gaze palsy, seizures and cataplexy. Laboratory features include the presence of sea blue cells and Niemann-Pick cells in bone marrow smears. NPC1 mutation can be identified in most of these patients and most of them are missense mutations.
[Show abstract][Hide abstract] ABSTRACT: Zhang J, Bao X, Cao G, Jiang S, Zhu X, Lu H, Jia L, Pan H, Fehr S, Davis M, Leonard H, Ravine D, Wu X. What does the nature of the MECP2 mutation tell us about parental origin and recurrence risk in Rett syndrome? The MECP2 mutations occurring in the severe neurological disorder Rett syndrome are predominantly de novo, with rare familial cases. The aims of this study were to provide a precise estimate of the parental origin of MECP2 mutations using a large Chinese sample and to assess whether parental origin varied by mutation type. The parental origin was paternal in 84/88 [95.5%, (95% confidence interval 88.77-98.75)] of sporadic Chinese cases. However, in a pooled sample including data from the literature the spectrum of mutations occurring on maternally and paternally derived chromosomes differed significantly. The excess we found of 'single base pair gains or losses' on maternally derived MECP2 gene alleles suggests that this mutational category is associated with an elevated risk of gonadal mosaicism, which has implications for genetic counseling.
[Show abstract][Hide abstract] ABSTRACT: To summarize the electroclinical characteristics of myoclonic atonic epilepsy (MAE) in children.
The clinical data, video electroencephalogram (EEG) and simultaneous electromyography (EMG) of MAE patients were analyzed. The treatment and its effects were followed up.
In 47 MAE patients, 25 had a history of febrile seizures (FS), 20 had a family history of FS or epilepsy. All patients had a normal development before the illness. The age of afebrile seizure onset was between 1.4 years to 5.8 years. The first seizure was generalized tonic-clonic seizure (GTCS) in 41 patients (87.2%). All patients had multiple seizure types, including 47 GTCS (97.9%), 34 myoclonic atonic seizures (72.3%), 47 myoclonic seizures (100%), 32 atonic seizures (68.1%), 36 atypical absences (76.6%) and 3 tonic seizures (6.4%). EEG backgrounds were slow or parietal θ rhythm, interictal EEG showed 1-4 Hz (predominant 2-3 Hz) generalized spike and wave or poly spike and wave discharges in all cases. Seizures were controlled by antiepileptic drugs (AEDs) in 41 patients (87.2%). Valproate was used in 37. Lamotrigine was used in 26. Mild mental retardation was observed in 10 children after the onset of the illness.
The clinical features of MAE included the following: the development was normal before the onset of the illness; the onset of seizure type was often GTCS. All patients had multiple generalized seizure types. Myoclonic atonic seizure was its characteristic seizure type. EEG showed generalized discharges. Early diagnosis and rational choice of AEDs are important for getting a better prognosis.
Zhonghua er ke za zhi. Chinese journal of pediatrics 08/2011; 49(8):577-82.
[Show abstract][Hide abstract] ABSTRACT: To investigate and analyze the clinical manifestations, classification, therapeutic approaches and follow-up of myasthenia gravis (MG) in children in order to improve its management and prognosis.
Clinical information of 135 children with MG, who were diagnosed between January 1993 to January 2008, were collected and retrospectively analyzed. And prospective following-up of these patients were conducted.
Among the 135 cases, 59 were males and 76 females, giving the ratio of M/F around 1:1.3. Totally, 115 cases (85.2%) were type I MG (ocular type), of which only 4.2% developed to generalized type during the subsequent clinical course. Type II MG (generalized type)was found in 18 cases (13.4%) and type III MG in two cases(1.5%). The onset age ranged from 5 month to 15 years, with 50.3% before three years and 80.7% before seven years. Upper respiratory tract infection was presented in 26.7% (36/135) of the sick children before the onset of MG. Among the 106 children being followed up, recurrence of the disease identified in 50.9% and the number of relapse ranged from 1 to 9. Altogether, 40.19% (43/106) of the cases were positive for anti-acetylcholine receptor antibodies (AchR-Ab) on the initial examination, and the AchR-Ab postitive rate showed no difference among different clinical subtypes and states. However, during the follow-up, 53% (9/17) of the recurrent cases, who were negative at the first onset, turned to be positive, and 37.97% (30/79) were positive for repetitive nerve stimulation in electromyogram test. There were 71 % (45/63) of all the cases showed reduced levels of CD4+ and/or CD3+ and/or CD8+. Thymus proliferation was found in 5.93% (8/135) through CT scan and thymoma in 1.48% (2/135). Steroids and anti-cholinesterase administration were effective in most cases with good prognosis.
Childhood MG, mainly type I, is relatively common in China, with specific characteristics which are different from western patients or adult MG in morbidity, sex distribution, progress, laboratory examination and treatment. The prevalence of myasthenia gravis crisis and mortality rate in MG children is low, and few are accompanied with thymoma. Most MG cases have a satisfied prognosis and few have neuropsychic sequela.
Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences 06/2011; 43(3):455-9.
[Show abstract][Hide abstract] ABSTRACT: To investigate the association of the polymorphisms of methionine metabolism genes and the phenotype of X-linked adrenoleukodystrophy (X-ALD) and clinical severity.
The clinical information of 120 X-ALD patients were analyzed and three genetic variants involved in the methionine metabolism, including cystathionine beta-synthase (CBS) c.844_855ins68, 5-methyltetrahydrofolate-homocysteine-S-methyltransferase (MTR) c.2756A to G, and transcobalamin 2 (TC2) c.776 C to G were analyzed by polymerase chain reaction and sequencing. The association between these polymorphisms and phenotype of X-ALD was studied.
The frequency of GG genotype of the TC2 c.776 C/G was higher in patients with central nervous system(CNS) demyelination than in controls (P= 0.012). However, the other two polymorphisms did not show any significant associations with the phenotypes.
The GG genotype of TC2 c.776 C/G may contribute to X-ALD phenotype.
Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics 06/2011; 28(3):279-82. DOI:10.3760/cma.j.issn.1003-9406.2011.03.009
[Show abstract][Hide abstract] ABSTRACT: Niemann-Pick disease type C (NP-C), derived from mutation of the NPC1 or NPC2 gene, is one of the recessive lysosomal lipid storage disorders that are difficult to diagnose and treat. Since NP-C has been rarely reported in China, we reviewed 7 patients with NP-C.
The 7 patients had been diagnosed with NP-C from 2007 to 2010 at our department and their laboratory and clinical data were analyzed.
The 7 patients, 5 males and 2 females, included 4 patients of late infantile subtype and 3 patients of juvenile subtype, in which patients 2 and 3 were siblings. Their clinical symptoms occurred from 4 to 10 years of age, exhibiting as progressive cognitive and language impairment as well as motor retrogression. Six patients were caught by focal or generalized seizures from 1 to 4 years after the onset of the disease. Vertical supranuclear gaze palsy, dysarthria, dysphagia, internal rotation and adduction of bilateral hands and splenomegaly occurred following the progress of clinical symptoms. Five patients had laughter-cataplexy. MRI showed mild brain atrophy in 6 patients. Reduction of total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol occurred in 6 patients. Sea-blue cells and Niemann-Pick cells were found in bone marrow smears. The activity of acid sphingomyelin enzyme was normal or only slightly lower. Supporting or symptomatic treatment improved common clinical symptoms.
NP-C is a rare autosomal recessive inherited lysosomal storage disease that affects the intellectual development of children and may lead to dementia, vegetative state or death. Clinical features of this disease include vertical supranuclear gaze palsy, seizures and cataplexy. Laboratory features include abnormal plasma cholesterol level, and sea-blue cells and Niemann-Pick cells in bone marrow smears. The treatments of the disease include supporting or symptomatic administration.
World Journal of Pediatrics 06/2011; 8(1):61-6. DOI:10.1007/s12519-011-0284-6 · 1.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To understand the clinical and genetic features of Huntington disease (HD).
The clinical data of HD cases from 2 Chinese families were analyzed and trinucleotide repeat in the IT15 gene were investigated in 9 of the two families by polymerase chain reaction and GeneScan.
Among the two pedigrees, 6 cases were ascertained as HD by genetic test. Genotypes of IT15 were heterozygous in these HD patients. CAG repeat of the patients in the HD chromosome were 40-78. In the two pedigrees, the onset age was earlier in the subsequent generations than that of their fathers. In pedigree 2, the onset age was inversely correlated with CAG repeat number. One out of the 6 cases was juvenile-onset type of Huntington disease, whose clinical symptoms were different from those of the adult-onset cases, especially the hypertonic manifestation.
HD is an autosomal dominant neurodegenerative disorder with genetic anticipation caused by enlargement of CAG repeat in IT15 gene. The clinical manifestation is different between the juvenile-onset and the adult-onset. The number of CAG repeat is inversely correlated with the onset age and clinical severity.
Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences 04/2011; 43(2):163-7.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the value of cryptococcal latex agglutination test in the diagnosis and treatment of cryptococcal meningitis in children.
The clinical data of 10 children with cryptococcal meningitis were retrospectively studied. Cryptococcal meningitis was confirmed based on clinical manifestations, India ink stain, cryptococcal latex agglutination test or cryptococcal culture. The outcome of antifungal treatment and the changes of latex agglutination test titer were followed up for 2 to 4 years.
Latex agglutination test and/or India ink stain were positive (titer 1 : 64-1 : 1024) in 8 patients in the first examination of cerebrospinal fluid. In the other 2 patients, latex agglutination test was positive (titer 1 : 256) in the fourth examination of cerebrospinal fluid in one, and India ink stain was positive in the eleventh examination in the other. After antifungal treatment, six patients were cured, two patients died, and two patients were lost to follow-up. The positive cryptococcal latex agglutination test (titer 1 : 2-1 : 16) was seen respectively in six, three, two and one cured patients 6 months, 1 year, 2 years and 4 years later.
The cryptococcal latex agglutination test of cerebrospinal fluid is valuable for the quick and early diagnosis of cryptococcal meningitis; however, the decision of withdrawal of antifungal treatment should not rely on the results of the test.
Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics 02/2011; 13(2):115-8.
[Show abstract][Hide abstract] ABSTRACT: To identify the parental origin of methyl-CpG-binding protein 2 (MECP2) gene mutations in Chinese patients with Rett syndrome.
Single nucleotide polymorphisms (SNPs) in intron 3 of the MECP2 gene were analyzed by PCR and sequencing in 115 patients with Rett syndrome. Then sequencing of the SNP region was performed for the fathers of the patients who had at least one SNP, to determine which allele was from the father. Then allele-specific PCR was performed and the products were sequenced to see whether the allele from father or mother harbored the mutation.
Seventy-six of the 115 patients had at least one SNP. Three hot SNPs were found in these patients. They were: IVS3+22C >G, IVS3+266C >T and IVS3+683C>T. Among the 76 cases, 73 had a paternal origin of MECP2 mutations, and the other 3 had a maternal origin. There were multiple types of MECP2 mutation of the paternal origin, including 4 frame shift, 2 deletion and 67 point (56C >T, 6C >G, 2A >G, 2G >T and 1A >T) mutations. The mutation types of the 3 patients with maternal origin included 2 frame shift and 1 point (C >T) mutation.
In Chinese RTT patients, the MECP2 mutations are mostly of paternal origin.
Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics 04/2010; 27(2):121-4. DOI:10.3760/cma.j.issn.1003-9406.2010.02.001
[Show abstract][Hide abstract] ABSTRACT: The KIR2DS4 variants differ in exon 5 and play a role in hematopoietic stem cells transplantation (HSCT). A sequence-based testing (SBT) and TOPO TA cloning system identifying and distinguishing alleles of the KIR2DS4 gene was established and applied to a total of 150 Chinese-Han individuals: 75 patients received T-cell-depleted HSCT and their unrelated donors. The majority (139) of the 150 samples (92.7%) were positive for KIR2DS4. Four of the nine known KIR2DS4 alleles, KIR2DS4 *00101, *003,*004, and *007, were identified. In the haplotype A/A group, a higher risk of acute graft-versus-host disease (aGVHD) was seen when the donor carried two full-length KIR2DS4 alleles (RR 9.0 [95% CI 1.2-66.9], P = 0.010). Our findings suggested that the expression of full-length 2DS4 (*001) in A/A group may contribute to a worse clinical outcome after URD-HSCT. These data would be beneficial for the selection of suitable donors.
International journal of laboratory hematology 04/2010; 32(6 Pt 2):625-32. DOI:10.1111/j.1751-553X.2010.01234.x · 1.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rett syndrome (RTT), an X-linked dominant neurodevelopmental disorder characterized by regression of language, stereotype hand movement and loss of purposeful hand use, is primarily caused by mutation of menthyl-CpG-binding protein 2 (MECP2). The 76 kb human MECP2 is characterized by three salient features: a very large intron 2 (60 kb), an 8.5 kb 3'-UTR with highly conserved regions and different polyadenylation sites, and a 40 kb intergenic region separating MECP2 from the nearest upstream gene. There are two isoforms of MeCP2, MeCP2e1 and MeCP2e2. The differences between the two isoforms, the function of the 3'-UTR and the long-range cis-regulatory sequences in the intergenic region were extensively studied. In contrast to initial report, recent studies show that MeCP2 binds not only to methylated promoters and silence transcription, but also to the sites outside of genes containing only a few of CpG islands. Furthermore, MeCP2 can function as both an activator and a repressor of transcription.
Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences 12/2009; 41(6):712-5.
[Show abstract][Hide abstract] ABSTRACT: To study the rate of subtelomeric rearrangements in patients with idiopathic mental retardation (MR) and to search the cause of MR.
DNA was extracted and purified from peripheral blood leukocytes of 180 patients with idiopathic MR. DNA was tested using specific subtelomeric multiplex ligation-dependent probe amplification (MLPA) kits P036B/C and P070 according to manufacturer's instructions. The amplification products were separated by capillary electrophoresis using an ABI 3100 automated sequencer and size standard. MLPA data were extracted by GeneScan Analysis software. Data normalization and analysis were performed with the built-in MLPA application in GeneMarker.
Among 180 patients with idiopathic MR, 12 had pathological subtelomeric deletions including 3 cases with a 4p deletion, 2 cases with a deletion at 9q and 22q respectively, 1 case with a deletion at 1p, 7p, 8p, 9q and 12q respectively. Subtelomeric rearrangements were responsible for 7% cases of idiopathic mental retardation.
Subtelomeric rearrangement is a common cause of idiopathic mental retardation.