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

Although some mutations are beneficial and are the driving force behind evolution, it is important to maintain DNA integrity and stability because it contains genetic information. However, in the oxygen-rich environment we live in, the DNA molecule is under constant threat from endogenous or exogenous insults. DNA damage could trigger the DNA damage response (DDR), which involves DNA repair, the regulation of cell cycle checkpoints, and the induction of programmed cell death or senescence. Dysregulation of these physiological responses to DNA damage causes developmental defects, neurological defects, premature aging, infertility, immune system defects, and tumors in humans. Some human syndromes are characterized by unique neurological phenotypes including microcephaly, mental retardation, ataxia, neurodegeneration, and neuropathy, suggesting a direct link between genomic instability resulting from defective DDR and neuropathology. In this review, rare human genetic disorders related to abnormal DDR and damage repair with neural defects will be discussed.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.14 no.1
• /
• pp.48-53
• /
• 2014

Smith-Lemli-Opitz syndrome (SLO) is a rare, autosomal recessive disease caused by an inborn error in cholesterol synthesis. Patients with this disease suffer from multiple malformations due to reduced activity of 7-dehydrocholesterol reductase (DHCR7), which increases 7-dehydrocholesterol (7DHC) and 8-dehydrocholesterol (8DHC) concentrations and decreases cholesterol concentration in body fluids and tissue. Here, we describe Korean siblings with SLO who were diagnosed recently, and performed a review of literature about Korean cases with SLO to date. Microcephaly and syndactyly of the second and third toes are the most common physical finding in SLOS patients. Other malformations including growth failure, cleft palate or bifid uvula, various heart malformation, genital ambiguity in males are also accompanied. Not all patients showed low levels of serum cholesterol, so DHCR7 mutation analysis can be helpful to confirmative diagnosis. Two mutations on p.R352 locus (p.R352W and p.R352Q) are commonly identified in Korean SLO patients. Although rare in Korea, SLO should be considered in the differential diagnosis of growth failure with intellectual disability, especially in patients with multiple congenital anomalies.

• Neonatal Medicine
• /
• v.17 no.1
• /
• pp.127-131
• /
• 2010

Supernumerary derivative (22) syndrome is a rare genomic syndrome. It is characterized by severe mental retardation, microcephaly, failure to thrive, preauricular tag or sinus, ear abnormalities, cleft and/or high-arched palate, micrognathia, kidney abnormalities, congenital heart defects, and genital abnormalities in males. In 99% of the cases, one of the parents is a balanced carrier of a translocation between chromosome 11 and chromosome 22. To date, there have been about 100 case reports of supernumerary derivative (22) syndrome. In most of the cases, supernumerary derivative (22) syndrome was the result of 3:1 meiotic segregation in the maternal 11;22 translocation carrier. We now report a case of 47,XX, + der(22)t(11;22)(q23;q11.2) resulting from 3:1 meiotic segregation of the paternal translocation carrier.

• Journal of Genetic Medicine
• /
• v.8 no.1
• /
• pp.58-61
• /
• 2011

Cases of interstitial deletions of the long arm of chromosome 17 are very rare, with only nine cases ever reported worldwide. We describe a 12-year-old boy with profound developmental delay, microcephaly, facial dysmorphism, contracture of the large joints and bilateral hearing loss. A chromosomal study using a peripheral blood sampled revealed 46,XY,del(17)(q22q23). To our knowledge, he is the first case of interstitial deletion of the long arm of chromosome 17 ever reported in Korea.

• Journal of Genetic Medicine
• /
• v.15 no.1
• /
• pp.34-37
• /
• 2018

A 1q21.1 microdeletion is an extremely rare chromosomal abnormality that results in phenotypic diversity and incomplete penetrance. Patients with a 1q21.1 microdeletion exhibit neurological-psychiatric problems, microcephaly, epilepsy, facial dysmorphism, cataract, and thrombocytopenia absent radius syndrome. We reported a neonate with confirmed intrauterine growth restriction (IUGR), micrognathia, glossoptosis, upper airway obstruction, facial dysmorphism, and eye abnormality at birth as well as developmental delay at the age of 1 year. These clinical manifestations, except for the IUGR and upper airway obstruction, in the neonate indicated a 1q21.1 microdeletion. Here, we report a rare case of a 1q21.1 microdeletion obtained via paternal inheritance in a newborn with upper airway obstruction caused by glossoptosis and tracheal stenosis.

• Journal of Interdisciplinary Genomics
• /
• v.1 no.1
• /
• pp.10-13
• /
• 2019

A 10-year and 5 month-old girl with developmental delay, intellectual disability, attention deficit hyperactivity disorder, poor weight gain, and microcephaly was transferred to our pediatric clinic for genetic evaluation. Her height was within the 5-10th percentile, and her weight was under the 3rd percentile. On the social maturity scale, her developmental status was scored as 3 years 9 months for social age, and the social quotient was 35.98. A chromosomal microarray analysis was performed and the microduplication at chromosome 16p was observed: arr[GRCh37] 16p11.2 (29580020_30190029)${\times}3$. Currently, the patient is diagnosed with Grade 2 intellectual disability and is attending a computerized cognitive rehabilitation class twice weekly. In addition, nutritional support and growth follow up are also ensured in the Pediatric Gastrointestinal and Endocrinology clinic.

• Korean Journal of Veterinary Research
• /
• v.61 no.2
• /
• pp.12.1-12.9
• /
• 2021

The mosquito-borne pathogen Zika virus may result in neurological disorders such as Guillain-Barré syndrome and microcephaly. The virus is classified as a member of the Flaviviridae family and its wide spread in multiple continents is a significant threat to public health. So, there is a need to develop animal models to examine the pathogenesis of the disease and to develop vaccines. To examine the clinical profile during Zika virus infection, we infected neonatal and adult wild-type mice (C57BL/6 and Balb/c) and compared the clinical signs of African-lineage strain (MR766) and Asian-lineage strain (PRVABC59, MEX2-81) of Zika virus. Consistent with previous reports, eight-week-old female Balb/c mice infected with these viral strains showed no changes in body weight, survival rate, and neurologic signs, but demonstrated increases in the weights of spleens and hearts. However, one-day-old neonates showed significantly lower survival rate and body weight with the African-lineage strain than the Asian-lineage strain. These results confirmed the pathogenic differences between Zika virus strains. We also evaluated the clinical responses in neonatal and adult mice of different strains. Our findings suggest that these are useful mouse models for characterization of Zika virus for vaccine development.

• Journal of Interdisciplinary Genomics
• /
• v.5 no.2
• /
• pp.18-23
• /
• 2023

Conventional evaluation method for identifying the organic cause of short stature has a low detection rate. If an infant who is small for gestational age manifests postnatal growth deterioration, triangular face, relative macrocephaly, and protruding forehead, a genetic testing of IGF2, H19, GRB10, MEST, CDKN1, CUL7, OBSL1, and CCDC9 should be considered to determine the presence of Silver-Russell syndrome and 3-M syndrome. If a short patient with prenatal growth failure also exhibits postnatal growth failure, microcephaly, low IGF-1 levels, sensorineural deafness, or impaired intellectual development, genetic testing of IGF1 and IGFALS should be conducted. Furthermore, genetic testing of GH1, GHRHR, HESX1, SOX3, PROP1, POU1F1, and LHX3 should be considered if patients with isolated growth hormone deficiency have short stature below -3 standard deviation score, barely detectable serum growth hormone concentration, and other deficiencies of anterior pituitary hormone. In short patients with height SDS <-3 and high growth hormone levels, genetic testing should be considered to identify GHR mutations. Lastly, when severe short patients (height z score <-3) exhibit high levels of prolactin and recurrent pulmonary infection, genetic testing should be conducted to identify STAT5B mutations.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.17 no.1
• /
• pp.18-23
• /
• 2017

${\beta}$-ureidopropionase deficiency (${\beta}$-UPD; OMIM # 613161) is a rare autosomal recessive inborn error of pyrimidine metabolism caused by mutations in the UPB1 gene and approximately 30 cases have been reported in the world. The clinical features of patients with ${\beta}$-UPD have been reported to vary from asymptomatic to severe developmental delays. However, the long-term clinical courses of patients with ${\beta}$-UPD have not yet been reported. A Korean girl was diagnosed with ${\beta}$-UPD at the age of 8 years and 10 months by targeted next-generation sequencing which was subsequently confirmed by Sanger sequencing. She had many clinical features such as poor oral feeding, failure to thrive, global developmental delay, microcephaly, frequent infection, and intractable epilepsy. She died suddenly of an unknown cause at the age of 11 years and 5 months. Here we report the long-term (i.e. lifelong) clinical aspects of a Korean patient with ${\beta}$-UPD.

• Korean Journal of Veterinary Research
• /
• v.41 no.3
• /
• pp.395-400
• /
• 2001

The present study analyze the morphological aspects of the cerebrum of mice with prenatal exposure to high and low dose (0.5, 1, 2 Gy) of $\gamma$-radiation on gestation day 12 or 16. The animal were allowed to give birth and the offspring were sacrificed at postnatal days 28 for gross and microscopic examination of cerebrum. Their body weight, brain weight, brain length, brain width, cortical thickness and area of cingulum bundle were examined. The histological and planimetric analysis were performed observing coronal sections. The gross malfomation (microcephaly) and abnormality of cortical architecture were prominent after exposure to 2 Gy on day 12 of gestation. significant dose-related reductions in body weight, brain weight, brain size were found in all irradiated groups. A significant change was found in thickness of the cerebral cortex and area of the cingulum bundle in the groups exposed to 0.5 Gy or more. There was no difference a lamina patter of six layers in cerebral cortex between the control and irradiated groups, but cell packing density increased significantly in the group exposed to 1 Gy or more. These results suggested that dose as low as 0.5 Gy could cause a morphologically reduce change in developing mouse cerebrum and exposure on day 12 of gestation to $\gamma$-irradiation is a particularly sensitive phase in causing malformation and abnormality of central nerve system.