• Journal of the Korean Chemical Society
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• v.50 no.1
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• pp.37-45
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• 2006

gel electrophoresis (CGE) with poly(ethylene oxide) has been applied to the measurement of CAG repeat number in Androgen receptor (AR) gene related to male infertility. Non-linear regression analysis was performed using the standard X174 RF/Hae III, 100bp step ladder DNA in order to investigate the exact number of CAG repeat. For 79 Korean infertile males and 89 controls, CAG repeats at exon 1 in AR gene was compared and analyzed by CGE. It turned out that CAG repeat numbers were 24.972.6 range, 17-29) for the infertile male, and 23.992.4 range, 18-29) for the control, respectively. P value (0.018) was less then 0.05, meaning that the result was statistically meaningful.

• Journal of Genetic Medicine
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• v.4 no.1
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• pp.84-87
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• 2007

Spinocerebellar Ataxia Type 3 (SCA 3) is a rare autosomal dominative disorder in which one of the neurodegenerative disorders is caused by a CAG repeat expansion on chromosome 14q32.1. The age at onset of disease is related to the size of the expanded CAG repeat. We present the prenatal diagnosis of SCA3 in a woman whose husband was known to carry an unstable CAG repeat expansion in the MJD gene. The diagnosis was made using PCR with a fluorescent probe for an expanded MJD allele. The normal ranges of (CAG)n of SCA3 are 14~38 repeats. The husband, who had a family history of SCA 3, has an expanded allele of 69 CAG repeats with a normal allele of 27 repeats. His wife had two normal alleles with 26 and 32 CAG repeats. The fetus had two normal alleles with 26 and 27 CAG repeats; consequently, the baby w as healthy. We report a case of prenatal diagnosis of SCA3 using a fluorescent PCR which is rapid and accurate.

• Annals of Clinical Neurophysiology
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• v.3 no.2
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• pp.151-155
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• 2001

SCA 1 is an autosomal dominant disorder. The phenotypic manifestations of SCA 1 are not specific, and thus, the diagnosis of SCA 1 rests on molecular genetic testing. The number of CAG repeats ranges from 6-44 in normal alleles and from 39-81 repeats in disease-causing alleles(chromosomal locus 6p22-23). The main clinical features of SCA 1 are ataxia, dysarthria, ophthalmoparesis, extrapyramidal signs without retinal degeneration. A 24-year-old woman with suspected family history presented with progressive cerebellar ataxia, dysarthria, ptosis, titubation and general weakness. Brain MRI revealed a moderate cerebellar atrophy. A genomic polymerase chain reaction(PCR) analysis showed 66 repeats at the SCA 1 locus.

• 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.