• Biomolecules & Therapeutics
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• v.25 no.3
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• pp.231-238
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• 2017

Myelin is a specialized structure of the nervous system that both enhances electrical conductance and insulates neurons from external risk factors. In the central nervous system, polarized oligodendrocytes form myelin by wrapping processes in a spiral pattern around neuronal axons through myelin-related gene regulation. Since these events occur at a distance from the cell body, post-transcriptional control of gene expression has strategic advantage to fine-tune the overall regulation of protein contents in situ. Therefore, many research interests have been focused to identify RNA binding proteins and their regulatory mechanism in myelinating compartments. Fragile X mental retardation protein (FMRP) is one such RNA binding protein, regulating its target expression by translational control. Although the majority of works on FMRP have been performed in neurons, it is also found in the developing or mature glial cells including oligodendrocytes, where its function is not well understood. Here, we will review evidences suggesting abnormal translational regulation of myelin proteins with accompanying white matter problem and neurological deficits in fragile X syndrome, which can have wider mechanistic and pathological implication in many other neurological and psychiatric disorders.

• 대한생식의학회:학술대회논문집
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• 2007.06a
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• pp.132-132
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• 2007

• BMB Reports
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• v.52 no.5
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• pp.304-311
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• 2019

The cytoplasmic FMR1-interacting protein family (CYFIP1 and CYFIP2) are evolutionarily conserved proteins originally identified as binding partners of the fragile X mental retardation protein (FMRP), a messenger RNA (mRNA)-binding protein whose loss causes the fragile X syndrome. Moreover, CYFIP is a key component of the heteropentameric WAVE regulatory complex (WRC), a critical regulator of neuronal actin dynamics. Therefore, CYFIP may play key roles in regulating both mRNA translation and actin polymerization, which are critically involved in proper neuronal development and function. Nevertheless, compared to CYFIP1, neuronal function and dysfunction of CYFIP2 remain largely unknown, possibly due to the relatively less well established association between CYFIP2 and brain disorders. Despite high amino acid sequence homology between CYFIP1 and CYFIP2, several in vitro and animal model studies have suggested that CYFIP2 has some unique neuronal functions distinct from those of CYFIP1. Furthermore, recent whole-exome sequencing studies identified de novo hot spot variants of CYFIP2 in patients with early infantile epileptic encephalopathy (EIEE), clearly implicating CYFIP2 dysfunction in neurological disorders. In this review, we highlight these recent investigations into the neuronal function and dysfunction of CYFIP2, and also discuss several key questions remaining about this intriguing neuronal protein.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.3
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• pp.179-188
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• 2007

Objectives: Many neurological diseases are known to be caused by expansion of trinucleotide repeats (TNRs). It is hard to diagnose the alteration of TNRs with single cell level for preimplantation genetic diagnosis (PGD). In this study, we describe methods optimized for PGD of TNRs related diseases such as Huntington's disease (HD), spinocerebellar ataxia 3 (SCA3) and fragile X syndrome (FXS). Methods: We performed the preclinical assays with heterozygous patient's lymphocytes by single cell PCR strategy. Fluorescent semi-nested PCR and fragment analysis using automatic genetic analyzer were applied for HD and SCA 3. Whole genome amplification with multiple displacement amplification (MDA) method and fluorescent PCR were carried out for FXS. Amplification and allele drop-out (ADO) rate were evaluated in each case. Results: The fluorescent semi-nested PCR of single lymphocyte showed 100.0% of amplification and 14.0% of ADO rate in HD, and 94.7% of amplification and 5.6% of ADO rate in SCA3, respectively. We could not detect the PCR product of CGG repeats in FXS using the fluorescent semi-nested PCR alone. After applying the MDA method in FXS, 84.2% of amplification and 31.3% of ADO rate were achieved. Conclusions: Fluorescent semi-nested PCR is a reliable method for PGD of HD and SCA3. The advanced MDA method overcomes the problem of amplification failure in CGG repeats of FXS case. Optimization of methods for single cell analysis could improve the sensitivity and reliability of PGD for complicated single gene disorders of TNRs.

• Clinical and Experimental Pediatrics
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• v.45 no.3
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• pp.311-319
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• 2002

Purpose : We have performed this study to obtain reference data for the distribution of chromosomal aberrations in Korea. Methods : We analyzed 1,180 chromosomal study cases from Kwang ju Christian Hospital during the past 25 years. 756 cases suspected of characteristic chromosomal aberration syndromes and 424 cases with hermaphroditism, mild sexual abnormalities, multiple anomalies, or mental & growth retardation were included. Results : The male to female ratio of autosomal aberration syndromes was 1.2 : 1. 78.6% of autosomal aberrations were diagnosed under 1 year of age, whereas 89.8% of sex chromosomal aberrations were diagnosed over 12 years of age. Among 1,180 cases, 612 ones had chromosomal aberrations(51.9%) : 590 of 756 cases suspected of chromosomal aberration syndromes had aberrations( 78.0%), whereas 22 of 424 showing the above other features had aberrations(5.2%). Autosomal aberrations appeared in 514 cases(83.8%) and sex chromosomal aberrations appeared in 98 cases(16.2%). The most frequently observed abberation in autosomal aberrations was Down syndrome, followed by E, D, B, A and C group aberrations. The most common abberation in sex chromosomal aberrations was Turner syndrome, followed by Klinefelter syndrome and Fragile X syndrome. Conclusion : It is of vital importance that patients suspected of chromosomal aberrations undergo chromosomal analysis. Further advanced chromosomal staining and molecular genetic methods will raise the detection rate of chromosomal aberrations.

• Journal of Environmental Health Sciences
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• v.32 no.6
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• pp.560-565
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• 2006

Extract of DNA for analysis of fragile X syndrome is usually performed by blood, the researches using hair root as specimen have been gradually spread. In this study, analyze fra X gene of the patients in mentally retarded children facilities was conducted using hair root DNA with molecular biologic test (PCR). The number of total subjects was 24, boys were 12, the average age was $17({\pm}3)$, and girls were 12, the average age was $18({\pm}2)$. In girls, normal size of band of 222 bp appeared in all lanes. Also, in all lanes except control in 517 bp, micro band appeared. Moreover, with appearance of band of 1198bp in lanes 2, 3, 4, 5, it is estimated that it is the band of full mutation whose CGG repeated sequences are more than 200. But it showed the peculiarity that it appeared with normal band in all the same lanes, thus it is not reasonable to judge it is the band of full mutation and further studies are needed. These results appeared in 50%, 6 of 12 mentally retarded girls. As the result of mentally retarded boys, normal band appeared in about 222 bp in control, however in experiment group, normal band did not appear. In 43%, 7 out of 12 boys, band did not either appeared in 1198bp, which showed different patterns from that of girls.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.1
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• pp.43-54
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• 1999

Klinefelter's syndrome is a very important disease in gynecologic endocrinologic fields, because the patients with this karyotype complain of infertility, azospermia and ambiguous genitalia. Y chromosome is an important chromosome which determine genetic sex and the structure of gonad and genitalia. In this study, to elucidate the cytogenetic characteristics and clinical features of Klinefelter's syndrome and Y chromosomal abnormalities in Korea, we studied 303 cases of Klinefelter's syndrome and 11 cases of Y chromosomal abnormalities which were diagnosed by chromosomal analysis at the Cytogenetic Laboratory, Institute of Reproductive Medicine and Population, Seoul National University for 12 years from January 1984 to December 1996. The results of this study showed as follows: 1. In a total of 9275 cases, there were 303 cases (3.3%) of Klinefelter's syndromes, 11 cases (0.1%) of Y chromosomal abnormalities. 2. In 102 cases of patients showed typical clinical features of Klinefelter's syndrome, 101 cases (99%) of them were diagnosed to Klinefelter's syndrome in karyotyping. 3. In 303 cases of Klinefelter's syndrome, there were 277 cases (91.4%) of 47,XXY complement, 16 cases (5.3%) of mosaicism, 2 cases (0.7%) of 48,XXXY, 5 cases (1.7%) of 48,XXYY and 3 cases (1.0%) of 49,XXXXY. 4. In 303 cases of Klinefelter's syndrome, 284 cases (93.7%) of them were diagnosed after puberty and only 19 cases (6.3%) of them were diagnosed before puberty. 5. In 303 cases of Klinefelter's syndrome, there were 146 cases (48.2%) of patients with infertility-associated chief complaints, 101 cases (33.3%) of patients with typical clinical features of Klinefelter's syndrome, 22 cases (7.3%) of patients with ambiguous genitalia. 6. In patients with Klinefelter's syndrome, 48,XXYY and 49,XXXXY had serious symptoms such as mental retardation, developmental delay, Down syndrome-like features, congenital anomalies, but 48,XXYY and other mosaicisms had infertility-associated symptoms or ambiguous genitalia. 7. The 8 cases of polysomy Y (XYY complement) showed several serious symptoms such as Down syndrome-like features, mental retardation, fragile X syndrome-like feature, congenital anomalies, ambiguous genitalia which could be detected before puberty.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.12 no.1
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• pp.71-78
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• 2001

Objectives：Few studies have examined the psychiatric properties or child developmental problems associated with inversion of chromosome 9. The purpose of this study is to examine the psychiatric properties of child patients who have inversion of chromosome 9, focused on behavioral problems and child developmental problems like motor or language developmental delay, intellectual impairment, and growth retardation. Methods：1) The authors examined the cases referred for cytogenetic examination from 1984 to 2000 at Seoul National University Hospital in Korea. The cases with the examination result of inversion of chromosome 9 were collected and informations about the departments which referred and the main reasons for referral were also checked. 2) 12 child subjects with inversion of chromosome 9 and their parents underwent psychiatric interview and parent questionnaire(child and adolescent past history questionnare, CBCL). 45 normal students whose sex and age were matched to patients were selected as a control group. Results：1) There were 165 cases of inversion of chromosome 9. The major departments which referred were Obstetrics and Gynecology(47.3%), Pediatrics(23.6%) and Child and Adolescent Psychiatry(17.0%). The major reasons for referral from the Pediatrics and the Child and Adolescent Psychiatry department (67 cases total) were intellectual impairment(35.8%), language or motor developmental delay(31.3%), suspected Fragile X syndrome(23.9%), and growth retardation(20.9%). 2) Compared to normal control group, the rate to be included in the clinical range with regard to the social problems profile was higher in patient group according to the CBCL results. The patient group had language and motor developmental delay. Conclusion：There is a possibility of inversion of chromosome 9 to be associated with child developmental problems or behavioral problems. This study is the first approach to evaluate the developmental aspects associated with inversion of chromosome 9.

• Journal of Genetic Medicine
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• v.13 no.1
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• pp.14-19
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• 2016

Purpose: We examined the prevalence and CGG/AGG repeat structure of expanded alleles of the FMR1 gene in preconceptional and pregnant Korean women. Materials and Methods: The CGG repeats in the FMR1 genes of 1,408 women were analyzed by polymerase chain reaction and Southern blot analysis. To estimate the prevalence of expansion alleles, the individuals were divided into low risk and high risk group. Results: Within this population, 98.4% had normal alleles and 1.6% had abnormal alleles including intermediate (0.6%), premutation (0.5%), full mutation (0.1%), and hemizygous (0.4%) alleles. There were 2 premutation alleles (1:666, 95% confidence interval [CI] 1:250-1,776) in the low risk group and 5 premutation alleles (1:15, 95% 1:6-36) in the high risk group. There were 8 intermediate alleles (1:167, 95% CI 1:130-213) in the low risk group and 1 intermediate alleles (1:76, 95% CI 1:11-533) in the high group. Six of the 7 premutation alleles did not contain AGG interruptions within the repeats and 1 had a single AGG interruption. Four of the 9 intermediate alleles contained 2-3 AGG, 4 had a single AGG, and 1 had no AGG interruptions. Conclusion: Our study demonstrates the prevalence and CGG/AGG structure of expansion alleles in Korean women. The identified premutation prevalence is higher than that of other Asian populations and lower than that of Caucasian populations. Although our study is limited by size and population bias, our findings could prove useful for genetic counseling of preconceptional or pregnant women.