• Anatomy and Cell Biology
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• v.51 no.4
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• pp.243-250
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• 2018

Because of its embryonic origin, the thyroid gland is predisposed to multiple anatomical variations and developmental anomalies. These include the pyramidal lobe, the origin of levator glandular thyroidae, the absence of the isthmus, ectopic thyroid, accessory thyroid tissues, etc. These anatomical variations are clinically significant to surgeons, anatomists, and researchers. The present study was designed to report anatomical variations and developmental anomalies of the thyroid gland in Ethiopian population. The study was conducted on 40 cadavers used for routine dissection classes. The thyroid gland was exposed and observed for any variations and developmental anomalies. The length, width, and thickness of the lobes were measured using a vernier caliper. Differences in the incidence of pyramidal lobe and absence of the isthmus between sexes were tested using a Pearson chi-square test. The mean length, width, and thickness of the right lobe were 4.24 cm, 1.8 cm, and 1.6 cm, respectively, whereas it was 4.08 cm, 1.8 cm, and 1.6 cm, respectively for that of the left lobe. The pyramidal lobe was noted in 52.5% of the cadavers. The levator glandulae thyroidae were prevalent in 40% of the cadavers. The isthmus mainly overlies the 2nd to 4th tracheal rings and was absent in 7.5% of the cadavers. Accessory thyroid tissue and double pyramidal lobes were noted in 2.5% of the cadavers. Most of the variations of the thyroid gland were seen frequently in female but it was not statically significant. Different clinically important and rare variations of the thyroid gland were found.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.2
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• pp.128-139
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• 2020

The purpose of this study was to examine the prevalence of developmental anomalies of permanent lateral incisor and eruption disturbances and analyze the association between two components. Panoramic radiographs of 3984 patients (aged 5 to 13 years) who visited the Department of Pediatric Dentistry of Seoul National University Dental Hospital between November 2016 and October 2017 were screened. The prevalence of developmental anomalies of permanent lateral incisors was 10.2%. The most common developmental anomalies were congenitally missing teeth(66.1%), followed by peg lateralis(33.5%). The prevalence of eruption disturbances was 16.5%. Among the patient with developmental anomalies of permanent lateral incisors, associated eruption disturbances were appeared on 31.1% of patients. Peg lateralis(p < 0.001), underdeveloped lateral incisors(p < 0.001) and dens invaginatus(p = 0.004) were associated significantly with eruption disturbance of permanent teeth. Eruption disturbance in patients with peg lateralis and dens invaginatus was most prevalent in maxillary canine. For patients with underdeveloped lateral incisor, eruption disturbance of maxillary central incisor was most frequent. It is important for patients with developmental anomalies of lateral incisors to detect associated eruption disturbance early through regular checkup. Diagnosis and treatment plan in view of such relationships is important in order to treat appropriately at the optimal time.

• Genomics & Informatics
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• v.15 no.3
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• pp.82-86
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• 2017

Chromosomal microarray (CMA) is a high-resolution, high-throughput method of identifying submicroscopic genomic copy number variations (CNVs). CMA has been established as the first-line diagnostic test for individuals with developmental delay (DD), intellectual disability (ID), autism spectrum disorders (ASDs), and multiple congenital anomalies (MCAs). CMA analysis was performed in 42 Korean patients who had been diagnosed with unexplained DD, ID, ASDs, and MCAs. Clinically relevant CNVs were discovered in 28 patients. Variants of unknown significance were detected in 13 patients. The diagnostic yield was high (66.7%). CMA is a superior diagnostic tool compared with conventional karyotyping and fluorescent in situ hybridization.

• Journal of Genetic Medicine
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• v.5 no.1
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• pp.1-6
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• 2008

Knowledge of developmental biology is essential for clinicians who seek to develop a rational approach to the diagnostic evaluation of patients with birth defects. After an accurate diagnosis, a clinician can make predictions about prognosis, recommend management options, and provide an indication of recurrence risk for the parents and relatives. In this paper, we first review the basic mechanisms of embryological development and clinical dysmorphology. We then review cellular and molecular mechanisms in development and related congenital anomalies. Developmental anomalies have a major impact on public health. Genetic counseling and prenatal diagnosis, with the option to continue or to terminate a pregnancy, are important for helping families faced with the risk of a serious congenital anomaly in their offspring. Moreover, primary prevention of birth defects, for example, supplementation of prenatal folic acid and prevention of consumption of alcohol which has teratogenic effects, can be accomplished using developmental biology knowledge.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.16-22
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• 2005

• Toxicological Research
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• v.17
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• pp.11-16
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• 2001

The development of the central nervous system is a continuous process during the embryonic and fetal periods. For a better understanding of congenital anomalies of central nervous system, three major events of normal development, i.e., neurulation (3 to 4 weeks), brain vesicle formation (4 to 7 weeks) and mantle formation (over 8 weeks) should be kept in mind. The first category of anomalies is neural tube defect. Neural tube defects encompass all the anomalies arise in completion of neurulation. The second category of central nervous system anomalies is disorders of brain vesicle formation. This is anomaly that applies for "the face predicts the brain". Holoprosencephaly covers a spectrum of anomalies of intracranial and midfacial development which result from incomplete development and septation of midline structures within the forebrain or prosencephalon. The last category of central nervous system malformation is disorders involving the process of mantle formation. In the human, neurons are generated in two bursts, the first from 8 to 10 weeks and next from 12 to 14 weeks. By 16 weeks, most of the neurons have been generated and have started their migration into the cortex. Mechanism of migration disorders are multifactorial. Abnormal migration into the cortex, abnormal neurons, faulty neural growth within the cortex, unstable pial-glial border, degeneration of neurons, neural death by exogenous factors are some of the proposed mechanism. Agyria-pachygyria are characterized by a four-layerd cortex. Polymicrogyria is gyri that are too numerous and too small, and is morphologically heterogeneous. Cortical dysplasia is characterized by the presence Q[ abnormal neurons and glia arranged abnormally in focal areas of the cerebral cortex. Neuroglial malformative lesions associated with medically intractable epilepsy are hamartia or hamartoma, focal cortical dysplasia and microdysgenesis.ysgenesis.

• Clinical and Experimental Pediatrics
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• v.46 no.3
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• pp.291-294
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• 2003

Ring chromosome 21 causes a multitude of phenotypes, ranging from severe abnormalities to normal. The proposed mechanism of ring formation, breakage of both short and long arms of a chromosome with subsequent end to end fusion, remains unproven. We encountered a 4-year-old boy who presented developmental delay, microcephaly, micrognathia, hypertelorism, low-set ears, mild optic nerve hypoplasia, cleft lip and palate, scoliosis and left foot valgus, but normal brain MRI. Chromosome study from peripheral blood showed 46,XY, r(21)(p11.2q22.1) karyotype. The authors report the first case of ring chromosome 21 in Korea with a review of the literature.

• Proceedings of the KSMRM Conference
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• 2004.09a
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• pp.54-60
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• 2004

• Advances in pediatric surgery
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• v.3 no.2
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• pp.108-116
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• 1997

The anatomical variations of the external genitalia including the hymen were observed prospectively in 1,500 female infants born between March, 1992 and July, 1992 at the Taegu Fatima Hospital. Careful inspection of the external genitalia was done within 24 hours after birth, and abnormal findings photographed. Almost all hymenal tissue appeared to be redundant. The hymen was annulus in 89.1 % of patients. Ninteen point nine percent had a central orifice and the remainder a ventral orifice. External ridges, intravaginal ridges, and clefts were present in 71.5 %, 50.7 % and 40.5 %, respectively. Congenital anomalies of the external genitalia were found in 20 patients(1.4 %). There were sixteen cases of hymenal cysts, two hymenal polyps, one imperforate hymen, and one Skene's duct cyst. Seven of the 16 hymenal cysts with stalks were excised and those without stalk were aspirated. Hymenal polyps were excised. Imperforate hymen was incised and drained, and Skene's duct cyst was aspirated successfully. The surgical procedure were done without anesthesia, and the results have been good. In conclusion, routine physical examination of the female newborn infant detects frequent developmental anomalies. The significance of those anomalies will be clarified after longitudinal long-term followup studies.

• Clinical and Experimental Pediatrics
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• v.59 no.1
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• pp.16-23
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• 2016

Purpose: The 1p36 deletion syndrome is a microdeletion syndrome characterized by developmental delays/intellectual disability, craniofacial dysmorphism, and other congenital anomalies. To date, many cases of this syndrome have been reported worldwide. However, cases with this syndrome have not been reported in Korean populations anywhere. This study was performed to report the clinical and molecular characteristics of five Korean patients with the 1p36 deletion syndrome. Methods: The clinical characteristics of the 5 patients were reviewed. Karyotyping and multiplex ligation-dependent probe amplification (MLPA) analyses were performed for genetic diagnoses. Results: All 5 patients had typical dysmorphic features including frontal bossing, flat right parietal bone, low-set ears, straight eyebrows, down-slanting palpebral fissure, hypotelorism, flat nasal roots, midface hypoplasia, pointed chins, small lips, and variable degrees of developmental delay. Each patient had multiple and variable anomalies such as a congenital heart defect including ventricular septal defect, atrial septal defect, and patent duct arteriosus, ventriculomegaly, cryptorchism, or hearing loss. Karyotyping revealed the 1p36 deletion in only 1 patient, although it was confirmed in all 5 patients by MLPA analyses. Conclusion: All the patients had the typical features of 1p36 deletion. These hallmarks can be used to identify other patients with this condition in their early years in order to provide more appropriate care.