• Journal of Genetic Medicine
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• v.7 no.2
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• pp.160-164
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• 2010

Structural abnormalities of the Y chromosome affect normal testicular differentiation and spermatogenesis. The present case showed a rare monocentric derivative Y chromosome with partial duplication of Yp including the SRY gene and deletion of Yq12 heterochromatin. The karyotype was 46,X,der(Y)(pter${\rightarrow}$q11.23::p11.2${\rightarrow}$pter).ish der(Y)(DYZ3+,DYZ1-,SRY++), confirmed through a FISH study. Even though the patient possessed an abnormal Y chromosome, testicular biopsy showed normal testicular volumes in the proband, with gonadal hormonal levels in the normal range but bilateral varicocele and hypospermatogenesis. We speculate that the abnormal Y chromosome arose from sister chromatids during Y chromosome recombination or intra chromosomal NAHR (non-allelic homologous recombination) during meiosis in the patient's father or in the very early stages of embryogenesis. The derivative Y chromosome might interfere in the meiotic stage of spermatogenesis, leading to the developmental arrest of germ cells. The present case illustrates that the infertility phenotype can have various causes. Also, it emphasizes the importance of accurate and various genetic analyses and could aid in male infertility treatment.

• Journal of Genetic Medicine
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• v.14 no.1
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• pp.43-47
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• 2017

Cat eye syndrome (CES) is a very rare chromosomal syndrome characterized by various malformations such as anal atresia, preauricular malformation, coloboma of the iris, and congenial heart and renal defects. This genetic disorder is caused by partial duplication of chromosome 22, mostly as a result of a supernumerary isodicentric marker chromosome idic(22)(q11.2). Various congenital abnormalities and extreme phenotypic variability in CES patients have been reported, which have made prenatal diagnosis of CES difficult. We report the first case diagnosed with CES prenatally by multiplex ligation-dependent probe amplification in a woman who was referred to our hospital, for a fetus presenting with heart anomaly.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.432-436
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• 2010

Transient neonatal diabetes mellitus (TNDM) has been associated with paternal uniparental isodisomy of chromosome 6, paternally inherited duplication of 6q24, or a methylation defect at a CpG island of the ZAC or HYMAI gene. We experienced a case of TNDM in which the patient presented with hyperglycemia, macroglossia, and intrauterine growth retardation, caused by a paternally derived HYMAI. An 18-day-old female infant was admitted to the hospital because of macroglossia and recurrent hyperglycemia. In addition to the macroglossia, she also presented with large fontanelles, micrognathia, and prominent eyes. Serum glucose levels were 200-00 mg/dL and they improved spontaneously 2 days after admission. To identify the presence of a maternal methylated allele, bisulfite-treated genomic DNA from peripheral blood was prepared and digested with BssHII after polymerase chain reaction (PCR) amplification with methylation-specific HYMAI primers. PCR and restriction fragment length polymorphism analysis showed that the patient had only the paternal origin of the HYMA1 gene. TNDM is associated with a methylation defect in chromosome 6, suggesting that an imprinted gene on chromosome 6 is responsible for this phenotype.