1.Diagnosis and Management of Vascular Ring Combined with Tracheal Compression in Infants and Neonates
shu-shui, WANG ; guo-hong, ZENG ; jian, ZHUANG ; zhi-wei, ZHANG ; mei-ping, HUANG ; yu-fen, LI ; wei, PAN ; ji-mei, CHEN ; shao-ru, HE
Journal of Applied Clinical Pediatrics 1986;0(01):-
Objective To explore the diagnosis and therapy experience of vascular ring combined with tracheal compression in infants and neonates.Methods Sixteen cases(including 7 boys and 9 girls,aged 1 day to 12 months)with vascular ring combined with tracheal compression hospitalized in Guangdong General Hospital from Jun.2004 to Dec.2009 were enrolled.In these 16 children,13 cases had congenital heart malformations.All children underwent X-ray,echocardiography and spiral computed tomography examination.Nine cases received bronchoscopy study.Fifteen cases performed surgical division of vascular ring with cardiopulmonary bypass and 1 case underwent vascular ring division and tracheoplasty.Eleven cases received management of congenital heart defect simultaneously.Results Vascular ring anomalies included pulmonary artery sling in 5 children,right aortic arch-left ligmentum/aberrant left subclavian artery in 8 cases,double aortic arch in 1 case,innominate artery compression in 1 case,and pulmonary sling combined with right aortic arch-aberrant left subclavian artery in 1 case.There were 2 ring-sling complex cases in this study.The diagnosis of vascular ring were correctly made by echocardiography in 7 children and made by spiral computed tomography in all 16 cases.Two cases combined with tracheal ring died.In the follow-up study of 11 cases,5 cases were still vulnerable to wheezing.Conclusions The common presentation of tracheal compression in infants and neonates associated with vascular ring are tachypea,stridor,and dyspnea.Multi-slices spiral computed tomography is an important imaging modality.Surgical divisions of vascular ring are safe procedure in most cases and tracheal compression can be relieved by this operation.In patients with severe tracheal stenosis,tracheoplasty should be recommended.
2.Analysis of the parental origin of de novo MECP2 mutations and X chromosome inactivation in fifteen sporadic cases with Rett syndrome.
Xing-wang ZHU ; Hong PAN ; Mei-rong LI ; Xin-hua BAO ; Jing-jing ZHANG ; Xi-ru WU
Chinese Journal of Pediatrics 2009;47(8):565-569
OBJECTIVERett syndrome (RTT) is a neurodevelopmental disorder occurring almost exclusively in females as sporadic cases due to de novo mutations in the methyl-CpG-binding protein 2 gene (MECP2). Familial cases of RTT are rare and are due to X-chromosomal inheritance from a carrier mother. Recently, DNA mutations in the MECP2 have been detected in approximately 84.7% of patients with RTT in China. To explain the sex-limited expression of RTT, it has been suggested that de novo X-linked mutations occur exclusively in male germ cells resulting therefore only in affected daughters. To test this hypothesis, we have analyzed the parental origin of mutations and the XCI status in 15 sporadic cases with RTT due to MECP2 molecular defects.
METHODSAllele-specific PCR was performed to amplify a fragment including the position of the mutation. The allele-specific PCR products were sequenced to determine which haplotype contained the mutation. It was then possible to determine the parent of origin by genotyping the single nucleotide polymorphism (SNP) in the parents. The degree of XCI and its direction relative to the X chromosome parent of origin were measured in DNA prepared from peripheral blood leucocytes by analyzing CAG repeat polymorphism in the androgen receptor gene (AR).
RESULTSExcept for 2 cases who had a frameshift mutation; all the remaining 13 cases had a C-->T transition mutation. Paternal origin has been determined in all cases with the C-->T transition mutation. For the two frameshift mutations, paternal origin has been determined in one case and maternal origin in the other. The frequency of male germ-line transmission in mutations is 93.3%. Except for 2 cases who were homozygotic at the AR locus, of the remaining 13 cases, 8 cases had a random XCI pattern; the other five cases had a skewed XCI pattern and they favor expression of the maternal origin allele.
CONCLUSIONDe novo mutations in sporadic RTT occur almost exclusively on the paternally derived X chromosome and that this is most probably the cause for the high female: male ratio observed in sporadic cases with RTT. Random XCI was the main XCI pattern in sporadic RTT patients. The priority inactive X chromosome was mainly of paternal origin.
Chromosome Aberrations ; Chromosomes, Human, X ; Female ; Humans ; Male ; Methyl-CpG-Binding Protein 2 ; genetics ; Mutation ; Polymorphism, Single Nucleotide ; Rett Syndrome ; genetics ; X Chromosome Inactivation
3.MECP2 gene mutations in twenty-six cases with atypical Rett syndrome.
Mei-rong LI ; Hong PAN ; Xin-hua BAO ; Yu-zhi ZHANG ; Sheng-ling JIANG ; Xi-ru WU
Chinese Journal of Pediatrics 2006;44(4):285-288
OBJECTIVERett syndrome (RTT) is an X-linked progressive neurodeveopmental disorder that almost exclusively affects girls, and is one of the most common causes of mental retardation in females, with an estimated prevalence of approximately 1 in 10,000 - 15,000 female individuals. Mutations in X-linked methyl-CpG-binding protein 2 (MECP2) gene, located on chromosome Xq28, have been found to be a cause of RS. A lot of mutations have been reported to be related to RS recently. Mutations are found in 70% - 85% of patients with classical RTT and in less than 50% of patients with atypical RS. Up to now, RTT is diagnosed based on a consistent counseling for clinical features and the established diagnostic criteria. The present study aimed to investigate frequency and type of mutation of MECP2 gene and if hot spot of mutation exits in patients with atypical RTT and find out the relationship between genotype and phenotype.
METHODSA systematic analysis of the entire coding region of MECP2 in 26 unrelated patients with atypical RTT was performed by polymerase chain reaction (PCR) and direct sequencing. Genomic DNA was extracted using standard procedures from the peripheral blood leukocytes of each patient. PCR amplification products were checked by 2% agarose gel electrophoresis and were subsequently sequenced with ABI 3730 Automated DNA Sequencer with both the forward and reverse primers. Mutational analyses were performed using normal human genomic MECP2 sequence as a reference (GenBank accession NO.AF030876).
RESULTSSeven mutations were identified in 12 of 26 patients. Most of the mutations were missense mutation; c.397C > T (R133C) was found in 3 of 26 patients; c.473C > T (T158M) and c.916C > T (R306C) were found in 2 of 26 patients, respectively; c.397A > G (R133H) and c.1005G > A (R335C) were found in 1 of 26 patients, respectively. One base pair deletion mutation (806delG) resulting in frameshift was found in 2 of 26 patients, and 1 base pair transversion at splice accept-site (IVS3-2A > T).
CONCLUSIONThe results of this study indicated that c.397C > T (R133C), c.473C > T (T158M) and c.916C > T (R306C) were hot spot mutations in MECP2 gene of patients with atypical RTT. There was some relationship between genotype and phenotype.
Base Sequence ; Child ; Female ; Gene Frequency ; Genetic Predisposition to Disease ; Humans ; Methyl-CpG-Binding Protein 2 ; genetics ; Molecular Sequence Data ; Mutation ; Mutation, Missense ; Phenotype ; Polymerase Chain Reaction ; Rett Syndrome ; genetics ; Sequence Analysis, DNA
4.X chromosome inactivation patterns in patients with Rett syndrome and their mothers and the parental origin of the priority inactive X chromosome.
Sheng-ling JIANG ; Xin-hua BAO ; Fu-ying SONG ; Hong PAN ; Mei-rong LI ; Xi-ru WU
Chinese Journal of Pediatrics 2006;44(9):648-652
OBJECTIVERett syndrome (RTT) is a severe childhood neurodevelopmental disorder mainly affecting females. The pathogenic gene is located at Xq28, which codes for the methyl-CpG-binding protein 2. MECP2 gene is affected by X chromosome inactivation (XCI). The different XCI patterns of females could affect the expression ratios of pathogenic gene, causing changes in clinical symptoms. In order to understand the XCI patterns in RTT patients and the relationship between XCI pattern, genotype and phenotype, the XCI patterns in patients with RTT and their mothers, the parental origin of the priority inactive X chromosome in RTT, and the relations of XCI patterns with genotype and phenotype in RTT cases were analyzed.
METHODSGenomic DNA was extracted from peripheral blood of 55 cases with RTT (52 with MECP2 mutations, 3 without mutations), 53 mothers of RTT cases and 48 normal female controls. DNA was digested with methylation sensitive restriction endonuclease Hpa II. Then the undigested and digested DNAs were amplified via PCR for the first exon of human androgen receptor (AR) gene. PCR products were analyzed by Genescan.
RESULTSThe heterozygotic rates of AR gene were 82%, 77% and 83% in RTT patients, mothers and controls, respectively. XCI distribution pattern of RTT was different from that of the mothers and control, P < 0.05. More mothers and controls than RTT patients were in the area of XCI 50:50 - 59:41. The differences between them were statistically significant (P < 0.05). No significant difference in XCI distribution patterns between mothers and the control groups was found (P > 0.05). Non-random XCI rates in the areas of XCI >or= 65:35 and >or= 80:20 were 53.35% and 17.8%, respectively, in RTT patients, compared with the mothers group (36.6%, 7.3%) and control group (35%, 10%), it was higher in RTT patients, but the difference was not statistically significant (P > 0.05). In 18 of 21 cases with XCI >or= 65:35, the priority inactive X chromosome was of paternal origin (85.7%). Variable XCI patterns were observed in the same gene mutation patients. The highly skewed XCI as well as the random XCI were found in patients with mild, severe and typical phenotype. The rate of highly skewed XCI in atypical patients was higher than that in typical RTT patients. The rate of highly skewed XCI in T158M was higher than the other type mutations. No highly skewed XCI was observed in cases with R133C mutation.
CONCLUSIONThe XCI distribution pattern of RTT patients was different from that of RTT mother and control groups. There was no significant difference in XCI distribution patterns between mothers and the control groups. It was not a main genetic pattern in RTT that mothers as the carriers to transmit the pathogenic gene to the patients. Non-random XCI was not the main XCI pattern in RTT patients. The priority inactive X chromosome was mainly of paternal origin. XCI could modify the clinical phenotype of RTT, but had limitations in explaining all the phenotypes manifested in RTT cases.
Adolescent ; Adult ; Child ; Child, Preschool ; Chromosomes, Human, X ; genetics ; Female ; Genetic Predisposition to Disease ; Genotype ; Heterozygote ; Humans ; Mothers ; Mutation ; Phenotype ; Receptors, Androgen ; genetics ; Rett Syndrome ; diagnosis ; genetics ; X Chromosome Inactivation ; genetics
5.Application of long range polymerase chain reaction and DNA direct sequencing in diagnosis of Rett syndrome.
Mei-rong LI ; Hong PAN ; Xin-hua BAO ; Guang-na CAO ; Xi-ru WU
Chinese Journal of Pediatrics 2007;45(8):579-582
OBJECTIVERett syndrome (RTT, MIM 312750) is a progressive neurodevelopmental disorder that affects females almost exclusively, caused by mutations in MECP2 gene on chromosome Xq28, with symptoms such as autism, severe mental deficiency, deceleration of head growth, ataxia, loss of purposeful hand function and characteristic stereotypic hand movements. Over 80% MECP2 mutations located in the exon 3 and exon 4 were confirmed by our work and large-scale studies. RTT is defined based on clinical presentation. It is difficult to diagnose in the early life without definite biochemical abnormality, but genetic test is helpful for this. The aim of this study was to investigate the feasibility and clinical significance of applying long range polymerase chain reaction (PCR) to RTT diagnosis and establish a simple, economic, efficient method of genetic diagnosis.
METHODGenomic DNA was extracted using standard procedures from the peripheral blood leukocytes of each patient. Long range polymerase chain reaction(PCR)and DNA direct sequencing were employed to analyze the exon 3 and 4 of MECP2 gene simultaneity in 40 patients with RTT. The PCR products were checked by using 1.5% agarose gel.
RESULTIn total, 18 different MECP2 mutations were identified in 33 of the 40 diagnosed sporadic female patients with RTT. Missense mutations were 16, followed by 14 nonsense mutations and 3 deletions. The 314 base pairs large deletion was identified. The p. T158M mutation (21%, 7/33) was the most common, followed in order of frequency by p. R255X (12%, 4/33), p. R168X and p. R106W (9%, 3/33) respectively, p. R270X and p. Y141X (6%, 2/33) respectively, p. R133C, p. D156H, p. P157L, p. P225R, p. Q244X, p. Q262X, p. R294X, p. R306C, P322L, c. 1005del G, c.1005-1318del 314 bp and c.1127-1179del 53 bp (3%, 1/33), respectively.
CONCLUSIONLong range PCR is a simple, economic, quick, precise method of genetic diagnosis and was able to find 83% MECP2 gene mutations in RTT patients in this study. It is helpful for RTT clinical diagnosis in early stage. On the other hand, it may detect recurrent mutations and large deletions at the same time.
Child ; Child, Preschool ; DNA ; analysis ; Exons ; genetics ; Female ; Humans ; Methyl-CpG-Binding Protein 2 ; genetics ; Mutation ; Polymerase Chain Reaction ; methods ; Rett Syndrome ; diagnosis ; genetics
6.Evaluation of Diagnosis and Preoperative Management of 53 Cases with Interrupted Aortic Arch in Infancy
yu-mei, LIU ; shao-ru, HE ; yun-xia, SUN ; jian, ZHUANG ; yu-hui, YU ; min-quan, ZHONG ; jin, ZHONG ; sui-xin, LIANG ; shao-han, NONG ; wei, PAN ; mei-ping, HUANG
Journal of Applied Clinical Pediatrics 2006;0(24):-
Objective To evaluate diagnosis and preoperative management of cases with interrupted aortic arch(IAA)in infancy.Methods Fifty-three infants who were admitted to our hospital from Jan.2001 to Nov.2007 were involved.Clinical data,findings of echocardiogram(Echo),spiral CT,MRI,angiocardiography,preoperative management,surgical repair and postoperative outcome were analyzed retrospectively.Results There were 38 boys and 15 girls,weighted 2.18-10.0(4.32?1.60)kg,aged 1 day to 12(3.05?3.53)months,of which 50.94% were neonates.Symptoms at presentation were 90.57% with tachypnea and 83.02% with difficulty in feeding.Eighty three point zero two percentage cases had different degree of congestive heart failure,37.74% of which were in grade Ⅲ heart function.All cases had weakened femoral pulse.All cases were performed Echo,38 cases of them diagnosed as IAA,6 cases as IAA or severe coarctation of aorta(CoA);they were diagnosed as IAA by CT,and 9 as severe CoA who were diagnosed as IAA via CT or operation.Thirty-three cases were performed CT,of which 15 underwent surgical repair,cardiovascular abnormalities revealed by CT were the same as those in surgical findings.Three cases were taken MRI,and 7 cases were performed angiocardiography.According to the results of Echo,CT,MRI,angiocardiography and surgical findings,35 cases were type A,15 cases were type B and 3 cases were type C.Preoperative treatment included maintaining patent ductus areriosis,management of heart failure and supportive treatment.After proper preoperative management of medication,most cases with congestive heart failure were improved.Twenty-six cases underwent surgical repair,16 survived,10 died du-ring perioperative stage.Main cause of death was severe low cardiac output.Conclusions Value of Echo in diagnosis of IAA is limi-ted.Combination of Echo with CT or MRI is a convenient and safe way to diagnose IAA,it can replace the traditional method of Echo combined with angiocardiography.Proper preoperative management is helpful to patients with IAA to pass to surgical repair,and makes for successful operation.
7.Primary screening for breast diseases among 17618 women in Wufeng area, a region with high incidence of cervical cancer in China.
Qinghua, ZHANG ; Dan, LIU ; Chuanying, HANG ; Ting, HU ; Jian, SHEN ; Meiling, HU ; Ru, YANG ; Zhilan, CHEN ; Zhuhui, LAI ; Guiling, LIU ; Yedong, MEI ; Qunying, XIANG ; Xiong, LI ; Kecheng, HUANG ; Shaoshuai, WANG ; Xiuyu, PAN ; Yuting, YAN ; Ye, LI ; QI
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(2):252-6
In this study, the current status for breast diseases in a region with high-incidence of cervical cancer were epidemiologically investigated. From March to August, 2009, 17618 women, from Wufeng area of Hubei province, China, were recruited to screen breast diseases by using breast infrared diagnostic apparatus. Other diagnostic methods, such as B-mode ultrasound, X-ray mammography, needle biopsy and pathological examination were, if necessary, used to further confirm the diagnosis. The screening showed that 5990 of 17618 cases (34.00%) had breast diseases, 5843 (33.16%) had mammary gland hyperplasia, 48 (0.27%) had breast fibroadenoma, 11 (0.06%) had breast carcinoma, and 88 (0.50%) had other breast diseases. The peak morbidity of breast cancer was found in the women aged 50-60 ages. The morbidity of breast cancer was significantly increased in women elder than or equal to 50 years old (n=8, 0.157%) in comparison with that in the subjects younger than 50 years old (n=3, 0.024%) (u=2.327, P<0.05). It was shown that the occurrence of breast diseases was concentrated in women aged 20-40 years, while the total morbidity reached its peak at the age of 30 years and then decreased sharply after age of 40. Compared with the patients elder than or equal to 40 years old (n=3289, 27.46%), the morbidity rate of breast diseases was significantly increased in women less than 40 years old (2648 cases, 47.18%; P<0.001). However, there was no significant difference in the morbidity of breast diseases between the age group of 20-29 years and that of 30-39 years (P=0.453), and both of them were high. There was no significant association between the morbidity of breast diseases and cervical cancer. Since the morbidity of breast diseases was higher among young women, more attention should be paid to the screening of breast diseases among young women for early diagnosis.
8.Analysis of the parental origin of MECP2 mutations in patients with Rett syndrome.
Jing-jing ZHANG ; Xin-hua BAO ; Guang-na CAO ; Sheng-ling JIANG ; Xing-wang ZHU ; Hong-mei LU ; Li-fang JIA ; Hong PAN ; Xi-ru WU
Chinese Journal of Medical Genetics 2010;27(2):121-124
OBJECTIVETo identify the parental origin of methyl-CpG-binding protein 2 (MECP2) gene mutations in Chinese patients with Rett syndrome.
METHODSSingle 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.
RESULTSSeventy-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.
CONCLUSIONIn Chinese RTT patients, the MECP2 mutations are mostly of paternal origin.
Base Sequence ; Child, Preschool ; DNA Mutational Analysis ; Fathers ; Female ; Humans ; Male ; Methyl-CpG-Binding Protein 2 ; genetics ; Mothers ; Mutation ; genetics ; Parents ; Polymorphism, Single Nucleotide ; Rett Syndrome ; genetics
9.Clinical study of neonatal cardiac output measurement methods.
Man-li ZHENG ; Xin SUN ; Jing ZHONG ; Shao-ru HE ; Wei PAN ; Cheng-cheng PANG ; Yun-xia SUN ; Yu-mei LIU
Chinese Journal of Pediatrics 2013;51(1):58-63
OBJECTIVETo assess agreement between the ultrasonic cardiac output monitor (USCOM) and conventional echocardiography (ECHO) in the measurement of cardiac output in newborn infants, investigate the accuracy and clinical utility of the USCOM in healthy neonates. To explore a more convenient, faster, more accurate hemodynamic monitoring method, for improving the outcome of the critically ill neonates.
METHODFrom October 1(st), 2011 to March 31(st), 2012, a total of 49 infants were included, 20 were term infants, 29 were preterm infants. Cardiac outputs were measured by both ultrasonic cardiac output monitor and echocardiography in all the infants, 60 times measurements were done in both the term infants the preterm infants. The cardiac output of the left and right ventricles, heart rate, diameter and velocity time integral of the aortic valve and pulmonary artery valve of each infant were recorded. The consistency of two methods was analyzed as described by Bland-Altman.
RESULTTerm the term infant group includea 20 term infants, 11 were male and 9 were female, the mean gestational age were (38.1 ± 0.56) weeks, mean age were (2 ± 1) days, mean weight were (3.2 ± 0.29) kg, mean Apgar score were 10. The mean left ventricular output measured by Echo was (242.3 ± 38.9) ml/(kg·min), measured by USCOM was (211.7 ± 38.5) ml/(kg·min); The mean right ventricular output measured by ECHO was (318.9 ± 47.0) ml/(kg·min), measured by USCOM was (340.7 ± 76) ml/(kg·min). Agreement between Echo and USCOM for left ventricular output (LVO) was (bias, ± limits of agreement, mean % error): (30.6 ± 51.1) ml/(kg·min), 21%, and for right ventricular output (RVO): (-21.8 ± 105) ml/(kg·min), 33.2%. The diameter of the aortic valve and pulmonary artery valve measured by conventional echocardiography were significantly larger than that estimated by ultrasonic cardiac output monitor (P < 0.001). The velocity time integral of the pulmonary artery valve measured by ultrasonic cardiac output monitor were significantly larger than measured by conventional echocardiography (P < 0.001). The heart rate, velocity time integral of the aortic valve measured by two methods had no significant differences (P > 0.05). The preterm neonates group included 29 preterm infants, 18 were male and 11 were female, the mean gestational age were (32.6 ± 2.8) weeks, mean age were (2 ± 1) days, mean weight were (1.88 ± 0.57) kg. All the infants were diagnosis as preterm infant, low birth weight. The mean left ventricular output measured by ECHO was (259.8 ± 70) ml/(kg·min), measured by USCOM was (235.6 ± 61.8) ml/(kg·min), the mean right ventricular output measured by ECHO was (318.9 ± 47.0) ml/(kg·min), measured by USCOM was (340.7 ± 76) ml/(kg·min). Agreement between Echo and USCOM for left ventricular output (LVO) was (bias, ± limits of agreement, mean % error): (24.1 ± 71.2) ml/(kg·min), 27.4%, and for right ventricular output (RVO): (-29.5 ± 192.9) ml/(kg·min), 51.8%. The diameter of the aortic valve and pulmonary artery valve measured by conventional echocardiography were significantly larger than estimated by ultrasonic cardiac output monitor (P < 0.001). The velocity time integral of the pulmonary artery valve measured by USCOM were significantly larger than that measured by conventional echocardiography (P < 0.001). The heart rate, velocity time integral of the aortic valve measured by two methods had no significant differences (P > 0.05).
CONCLUSIONAgreement between USCOM and conventional ECHO in the LVO measurement is acceptable, both in the term group and the preterm group. LVO measurement measured by USCOM is recommended. The accuracy and clinical utility of the USCOM in neonates is acceptable. USCOM is a convenient, fast and accurate hemodynamic monitoring method in neonates. While the agreement between USCOM and conventional ECHO in the RVO measurement is poor, especially in the preterm group, the results of the RVO cannot be considered interchangeable in the two methods.
Cardiac Output ; Echocardiography, Doppler ; instrumentation ; methods ; Female ; Heart Rate ; physiology ; Hemodynamics ; physiology ; Humans ; Infant ; Infant, Newborn ; Infant, Premature ; Intensive Care, Neonatal ; Male ; Monitoring, Physiologic ; methods ; Reproducibility of Results ; Sensitivity and Specificity ; Ventricular Function ; physiology
10.Correlation between MECP2 genotype and phenotype in Chinese patients with Rett syndrome.
Mei-rong LI ; Hong PAN ; Xin-hua BAO ; Xing-wang ZHU ; Guang-na CAO ; Yu-zhi ZHANG ; Xi-ru WU
Chinese Journal of Pediatrics 2009;47(2):124-128
OBJECTIVERett syndrome (RTT) is a neurodevelopmental disorder that represents one of the most common genetic causes of mental retardation in girls. The aim of this study was to investigate the correlation between MECP2 genotype and phenotype and thereby not only to provide assistance for clinical care, but also facilitate clinical genetic counseling.
METHODIndividual phenotype characteristic and clinical severity of 126 children with RTT diagnosed by molecular genetic methods were evaluated by using scales of Kerr et al and Scala et al. Statistical package SPSS 12.0 was used for analyses of data. Since the majority of the data were not normally distributed, non-parametric tests were used. The Kruskal-Wallis test/Wilcoxon Mann-Whitney test was employed to compare total severity phenotype scores. The Fisher exact test was used for comparing rates. Statistical significance was set at P < 0.05.
RESULTThere were no significant differences in the average overall scores for RTT patients with mutations in the region of methyl-CpG-binding domain (MBD) compared with those mutations in the transcription repression domain (TRD) and C terminal segment (CTS), also patients with nonsense mutations compared with missense mutations, frameshift mutations and large deletions (P > 0.05). The RTT patients with nonsense mutations located in the region of MBD have more severe phenotype than those with missense mutations in the same region (P = 0.016). Among p.T158M, p.R168X, c.806delG and p.R255X, there were no significant differences in the average overall scores (P > 0.05), but there were significant differences in language skill (P = 0.028) and in language impairment rate at different level (P = 0.019).
CONCLUSIONThere are relationships between MECP2 genotype and phenotype:the RTT patients with nonsense mutations located in MBD tend to develop more severe phenotype;there are significant differences in language skill and language impairment rate in the groups with p.T158M, p.R168X, c.806del and p.R255X, which had higher frequency in children below five-years of age and the p.R168X present with most severe impairment.
Adolescent ; Child ; Child, Preschool ; Female ; Genotype ; Humans ; Infant ; Methyl-CpG-Binding Protein 2 ; genetics ; Phenotype ; Rett Syndrome ; genetics