• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.14-18
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• 2016

Pediatric epilepsy can be caused by various conditions, including specific syndromes. 1p36 deletion syndrome is reported in 1 in 5,000-10,000 newborns, and its characteristic clinical features include developmental delay, mental retardation, hypotonia, congenital heart defects, seizure, and facial dysmorphism. However, detection of the terminal deletion in chromosome 1p by conventional G-banded karyotyping is difficult. Here we present a case of epilepsy with profound developmental delay and characteristic phenotypes. A 7-year-and 6-month-old boy experienced afebrile generalized seizure at the age of 5 years and 3 months. He had recurrent febrile seizures since 12 months of age and showed severe global developmental delay, remarkable hypotonia, short stature, and dysmorphic features such as microcephaly; small, low-set ears; dark, straight eyebrows; deep-set eyes; flat nasal bridge; midface hypoplasia; and a small, pointed chin. Previous diagnostic work-up, including conventional chromosomal analysis, revealed no definite causes. However, array-comparative genomic hybridization analysis revealed 1p36 deletion syndrome with a 9.15-Mb copy loss of the 1p36.33-1p36.22 region, and fluorescence in situ hybridization analysis (FISH) confirmed this diagnosis. This case highlights the need to consider detailed chromosomal study for patients with delayed development and epilepsy. Furthermore, 1p36 deletion syndrome should be considered for patients presenting seizure and moderate-to-severe developmental delay, particularly if the patient exhibits dysmorphic features, short stature, and hypotonia.

• Journal of Genetic Medicine
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• v.2 no.2
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• pp.49-51
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• 1998

Wolf-Hirschhorn syndrome (WHS) is caused by a deletion of the short arm on chromosome 4 and is characterized by multiple congenital abnormalities, growth and mental retardation. In this case report, we performed amniocentesis for the chromosome analysis on a 25-year-old pregnant woman at 16 weeks of gestation whom we suspected of Edward's syndrome by the triple test of maternal serum and ultrasonography. The result of analysis revealed a karyotype of the fetus with 46,XY,del(4)(p15) by trypsin Giemsa's banding technique. With the result, we were able to diagnose the fetus as having WHS. As such, after therapeutic termination of the pregnancy, we confirmed WHS through the sampling of tissue by both trypsin Giemsa's banding and fluorescence in situ hybridization (FISH) method. To determine the origin of the WHS, we further tested the karyotypes of the parents. As parental karyotypes were found to be normal, we determined the case of the fetal WHS to be de novo.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.13 no.1
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• pp.57-61
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• 2013

Glycerol kinase deficiency (GKD) is an X-linked recessive enzyme defect characterized biochemically by hyperglycerolaemia and glyceroluria. GK gene is located on the short arm of X chromosome 21.3 region tandemly with AHC gene, and DMD gene and there is a long deletion resulting in contiguous gene deletion syndrome. In Korea there was a report of contiguous gene deletion syndrome of adrenal hypoplasia congenita, glycerol kinase deficiency and Duchenne muscular dystrophy but no isolated glycerol kinase deficiency. This is the first case of isolated glycerol kinase deficiency confirmed by organic acid analysis and gene analysis in Korea.

• Journal of Genetic Medicine
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• v.18 no.2
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• pp.110-116
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• 2021

Microdeletions of chromosome 22q11.2 are one of the most common microdeletions occurring in humans, and is known to be associated with a wide range of highly variable features. These deletions occur within a cluster of low copy repeats (LCRs) in 22q11.2, referred to as LCR22 A-H. DiGeorge (DGS)/velocardiofacial syndrome is the most prevalent form of a 22q11.2 deletions, caused by mainly proximal deletions between LCR22 A and D. As deletions of distal portion to the DGS deleted regions has been extensively studied, the recurrent distal 22q11.2 microdeletions distinct from DGS has been suggested as several clinical entities according to the various in size and position of the deletions on LCRs. We report a case of long-term follow-up of a female diagnosed with a 22q11.2 distal deletion syndrome, identified a deletion of 1.9 Mb at 22q11.21q11.23 (chr22: 21,798,906-23,653,963) using single nucleotide polymorphism array. This region was categorized as distal deletion type of 22q11.2, involving LCR22 D-F. She was born as a preterm, low birth weight to healthy non-consanguineous Korean parents. She showed developmental delay, growth retardation, dysmorphic facial features, and mild skeletal deformities. The patient underwent a growth hormone administration due to growth impairment without catch-up growth. While a height gain was noted, she had become overweight and was subsequently diagnosed with pre-diabetes. Our case could help broaden the genetic and clinical spectrum of 22q11.2 distal deletions.

• Journal of Interdisciplinary Genomics
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• v.5 no.1
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• pp.1-4
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• 2023

Kleefstra syndrome is caused by chromosome 9q34.3 deletion or heterozygous mutations in the Euchromatin Histone Methyl Transferase 1 (EHMT1) gene. The prevalence is estimated 1:25,000 to 1:35,000. Intellectual disability, distinctive facial features, hypotonia in childhood can be accompanied. The spectrum of Kleefstra syndrome includes behavioral/psychiatric problems, hearing and visual impairments, seizures, congenital heart defects, genitourinary defects, and obesity. Therefore, it is necessary to understand the pathophysiology and various manifestation of Kleefstra syndrome and discussing with a multidisciplinary team will help diagnose and treat Kleefstra syndrome patients.

• Clinical and Experimental Pediatrics
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• v.48 no.12
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• pp.1389-1389
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• 2005

The long arm duplication of chromosome 3 was reported for the first time in 1966 by Falek et al., and Hirschhorn et al. came to identify the duplication of 3q21${\rightarrow}$qter region in 1973. In most cases of duplication 3q syndrome patients, pure duplication of 3qter is believed to be rare and is often reported accompanied with deletion of another segment of the chromosome. Approximately 75 percent of parents of the patient in the meantime have been demonstrated to have unbalanced translocations or inversions of the chromosome. Partial deletion of the distal part of the short arm of chromosome 3 was first reported by Verjaal and De Nef in 1978 and terminal deletion of chromosome 3 (3p25-qter) has been observed in most cases. In karyotyping of chromosomes of immature infants showing the manifestations of flat occiputs, low set ears, hypertelorism, broad nasal roots, thin lips, web necks, hypotonia, hypertrichosis skin, cryptorchidism etc, we experienced a case diagnosed as 46,XY, rec(3)dup(3)(q21)del(3)(p25)inv(3)(p25q21).

• Clinical and Experimental Reproductive Medicine
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• v.49 no.2
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• pp.101-109
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• 2022

Objective: Y chromosome microdeletions are the second most common genetic cause of male infertility after Klinefelter syndrome. The aim of this study was to determine the patterns of Y chromosome microdeletions among infertile Mongolian men. Methods: A descriptive study was performed on 75 infertile men from February 2017 to December 2018. Y chromosome microdeletions were identified by polymerase chain reaction. Semen parameters, hormonal levels, and testis biopsy samples were examined. Results: Among 75 infertile men, two cases of Y chromosome microdeletions were identified. The first case had an AZFa complete deletion and the other had an AZFc partial deletion. This study found that the proportion of Y chromosome microdeletions among infertile Mongolian men was 2.66%. Conclusion: The findings can be applied to in vitro fertilization and assisted reproductive technology, and our results will help clinicians improve treatment management for infertile Mongolian couples.

• Journal of Genetic Medicine
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• v.15 no.1
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• pp.38-42
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• 2018

WAGR (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) syndrome is a rare contiguous gene deletion syndrome caused by deleting genes including WT1 and PAX6 genes in 11p13 region, which is characterized by Wilms tumor, aniridia, genitourinary abnormalities, and intellectual disability. We report the clinical and cytogenetic characteristics of one Korean patient with WAGR syndrome. The patient shows bilateral sporadic aniridia and genital anomalies at 2 months of age. A heterozygous 14.5 Mb interstitial deletion of 11p14.3p12 region was detected by array comparative genomic hybridization. At 2 years and 10 months of age, Wilms tumor is found through regularly abdominal ultrasonography and treated by chemotherapy, radiation therapy and surgery.

• Korean Journal of Clinical Laboratory Science
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• v.42 no.2
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• pp.97-102
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• 2010

The two new female cases of Angelman syndrome (AS) were described, which diagnosed on the basis of clinical features (dysmorphic facial features, severe mental retardation with absent speech, peculiar jerky movements, ataxic gait and paroxysms of inappropriate laughter) and neurophysiological findings. Failure to detect the deletion of the long arm of chromosome 15 or the absence of epileptic seizure were not considered sufficient to exclude a diagnosis of AS. Feeding problems, developmental delay and early signs of ataxia, especially tremor on handling objects and unstable posture when seated, proved effective as the clinical markers for early diagnosis of AS. Most of the authors agreed about the existence of three main EEG patterns in AS which may appear in isolation or in various combinations in the same patient. The most frequently observed pattern in children has prolonged runs of high amplitude rhythmic 2-3 Hz activity predominantly over the frontal region with superimposed interictal epileptiform discharges. High amplitude rhythmic 4-6 Hz activity, prominent in the occipital regions, with spikes, which can be facilitated by eye closure, is often seen in children under the age of 12 years. The EEG findings are characteristic of AS when seen in the appropriate clinical context and can be helpful to identify AS patients at an early age when genetic counselling may be particularly important.

• Journal of Interdisciplinary Genomics
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• v.5 no.2
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• pp.13-17
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• 2023

KBG syndrome (KBGS) is a multisystem disorder characterized by short stature, distinctive facial features including macrodontia of upper central permanent incisors, and developmental/cognitive delay. It is caused by variants or deletion of Ankyrin Repeat Domain 11 (ANKRD11) located in chromosome 16q24.3. Since its initial report in 1975, KBG syndrome has been recognized as an exceedingly rare disorder. However, recent advancements in genetic diagnostic techniques have led to an increase in both the diagnosis rate and the number of reported cases, contributing to a rapid increase in its global prevalence. We review the clinical aspects of KBGS, including previously reported and newly reported cases, as well as the related genetic patterns discovered so far.